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NLI Technical Specification

Description: OpenSS7 Project Library Transport NLI

A PDF version of this document is available here.

Network Layer Interface

Network Layer Interface Specification

About This Manual

This is Edition 7.20141001, last updated 2014-10-25, of The Network Layer Interface Specification, for Version 1.1 release 7.20141001 of the OpenSS7 package.


Preface

Notice

Software in this document and related software is released under the AGPL (see GNU Affero General Public License). Please note, however, that there are different licensing terms for some of the manual package and some of the documentation. Consult permission notices contained in the documentation of those components for more information.

This document is released under the FDL (see GNU Free Documentation License) with no invariant sections, no front-cover texts and no back-cover texts.

Abstract

This document is a Specification containing technical details concerning the implementation of the Network Layer Interface for OpenSS7. It contains recommendations on software architecture as well as platform and system applicability of the Network Layer Interface.

This document specifies a Network Layer Interface Specification in support of the OpenSS7 X.25 Packet Layer Protocol (PLP) protocol stacks. It provides abstraction of the X.25 Packet Layer interface to these components as well as providing a basis for X.25 Packet Layer control for other X.25 Packet Layer protocols.

Purpose

The purpose of this document is to provide technical documentation of the Network Layer Interface. This document is intended to be included with the OpenSS7 STREAMS software package released by OpenSS7 Corporation. It is intended to assist software developers, maintainers and users of the Network Layer Interface with understanding the software architecture and technical interfaces that are made available in the software package.

Intent

It is the intent of this document that it act as the primary source of information concerning the Network Layer Interface. This document is intended to provide information for writers of OpenSS7 Network Layer Interface applications as well as writers of OpenSS7 Network Layer Interface Users.

Audience

The audience for this document is software developers, maintainers and users and integrators of the Network Layer Interface. The target audience is developers and users of the OpenSS7 SS7 stack.

Revision History

Take care that you are working with a current version of this documentation: you will not be notified of updates. To ensure that you are working with a current version, check the OpenSS7 Project website for a current version.

A current version of this specification is normally distributed with the OpenSS7 package, openss7-1.1.7.20141001.1

Version Control

Although the author has attempted to ensure that the information in this document is complete and correct, neither the Author nor OpenSS7 Corporation will take any responsibility in it. OpenSS7 Corporation is making this documentation available as a reference point for the industry. While OpenSS7 Corporation believes that these interfaces are well defined in this release of the document, minor changes may be made prior to products conforming to the interfaces being made available. OpenSS7 Corporation reserves the right to revise this software and documentation for any reason, including but not limited to, conformity with standards promulgated by various agencies, utilization of advances in the state of the technical arts, or the reflection of changes in the design of any techniques, or procedures embodied, described, or referred to herein. OpenSS7 Corporation is under no obligation to provide any feature listed herein.

$Log: nli.texi,v $
Revision 1.1.2.2  2011-02-07 02:21:41  brian
- updated manuals

Revision 1.1.2.1  2009-06-21 10:54:48  brian
- added files to new distro

ISO 9000 Compliance

Only the TeX, texinfo, or roff source for this maual is controlled. An opaque (printed, postscript or portable document format) version of this manual is a UNCONTROLLED VERSION.

Disclaimer

OpenSS7 Corporation disclaims all warranties with regard to this documentation including all implied warranties of merchantability, fitness for a particular purpose, non-infrincement, or title; that the contents of the manual are suitable for any purpose, or that the implementation of such contents will not infringe on any third party patents, copyrights, trademarks or other rights. In no event shall OpenSS7 Corporation be liable for any direct, indirect, special or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action or contract, negligence or other tortious action, arising out of or in connection with any use of this documentation or the performance or implementation of the contents thereof.

U.S. Government Restricted Rights

If you are licensing this Software on behalf of the U.S. Government ("Government"), the following provisions apply to you. If the Software is supplied by the Department of Defense ("DoD"), it is classified as "Commercial Computer Software" under paragraph 252.227-7014 of the DoD Supplement to the Federal Aquisition Regulations ("DFARS") (or any successor regulations) and the Government is acquiring only the license rights granded herein (the license rights customarily provided to non-Government users). If the Software is supplied to any unit or agency of the Government other than DoD, it is classified as "Restricted Computer Software" and the Government’s rights in the Software are defined in paragraph 52.227-19 of the Federal Acquisition Regulations ("FAR") (or any successor regulations) or, in the cases of NASA, in paragraph 18.52.227-86 of the NASA Supplerment to the FAR (or any successor regulations).

Acknowledgements

The OpenSS7 Project was funded in part by:

Thanks to the subscribers to and sponsors of The OpenSS7 Project. Without their support, open software like this would not be possible.

As with most open source projects, this project would not have been possible without the valiant efforts and productive software of the Free Software Foundation, the Linux Kernel Community, and the open source software movement at large.


1 Introduction

The Network Layer Interface (NLI) was developed by Spider Systems, Ltd., (now a division of Emerson Power), and is widely available on many platforms. For example, AIX AIXlink/X.25, HP-UX HP X.25/9000, Solaris Solstice X.25 and SunLink X.25, IRIX IRIS SX.25, PT X.25 and SBE X.25 implement the Network Layer Interface (NLI).

The Network Layer Interface (NLI) was designed to be used directly with standard STREAMS system calls and does not require the use of a cooperating user space shared library. Applications programs directly use the getmsg(2s), getpmsg(2s), putmsg(2s), putpmsg(2s) and ioctl(2s) system calls.2 Nevertheless, user shared object libraries can easily be constructed using this STREAMS service primitive interface.

The system header files that must be included when compiling user applications, or STREAMS drivers and modules that use the interface, are detailed in NLI Header Files.

A user library, libsx25, is provided, not for interfacing to the message primitive service interface, but for providing various helper functions when using the STREAMS service interface. This library is detailed in NLI Library.


1.1 History

The original UNIX® System V Release 3.2 with the Network Service Utilities (NSU) package, defined three levels of interface corresponding to boundaries of the OSI Model, as follows:

Transport Layer Inteface

This interface later turned into the Transport Provider Interface (TPI) that was standardized by UNIX International and later standardized by the Open Group. Two libraries existed in SVR 4 and X/Open: the Transport Layer Interface (TLI) library from SVR 4 and the X/Open Transport Interface (XTI) library from the Open Group. The Open Group also standardized the XTI interface for X.25.

Network Layer Interface

This interface later turned into the Network Provider Interface (NPI) that was standardized by UNIX International, but was not standardized by the Open Group. The NPI was used for X.25 as well as CONS in accordance with X.223. No library was provided by SVR 4 for this interface; however, GCOM specified an NPI API Library also provided by OpenSS7. For X.25, Spider Systems, Ltd. provided the Network Layer Interface (NLI) that is the subject of this specification.

Link Layer Interface

This interface later tunred into the Data Link Provider Inteface (DLPI) that was standardized by UNIX International and later standardized by the Open Group. No library was provided by SVR 4 for this interface; however, GCOM specifies a DLPI API Library also provided by OpenSS7. For X.25, Spider Systems, Ltd. provided the Link Layer Interface (LLI) that is the subject of a companion specification. Sun Microsystems has recently specified a DLPI Library for Solaris 11 that is also provided by OpenSS7.

Media Access Control

This interface was proposed by NCR Comten as the Communications Device Interface (CDI) that was not standardized. SVR 4 provided a Media Access Control (MAC) interface also supported by OpenSS7. Spider Systems, Ltd. X.25 does not directly use an interface at this level but, instead relies on access at the LLI.

Wide Area Network

This interface was proposed by NCR Comten as the Communications Device Interface (CDI) that was not standardized. For X.25, Spider Systems, Ltd. provided the Wide Area Network (WAN) Interface that is the subject of a companion specification.

The Network Layer Interface (NLI) specified by Spider Systems, Ltd. was the most widespread implementation of X.25 found on UNIX® and Unix-like systems.


1.2 Development

Although the Spider Systems, Ltd. Network Layer Interface (NLI) that is the subject of this specification was and is still in widespread use for the implementation of X.25 on UNIX® and Unix-like systems, it must be stressed that this is a legacy interface. It is provided by The OpenSS7 Project only for the purpose of porting legacy applications, drivers and modules to Linux. The following principles should be adhered to:

  • The only formal standard interface for X.25 was specified by the Open Group using the X/Open Transport Interface library, specified in reference XX25. This interface is supported by OpenSS7 using the XX25 module described in XX25 Module.

    This interface alone should be used for new applications.

  • For intermodule communications, the only industry standard interface for X.25 was specified by UNIX International as the Network Provider Interface (NPI) specified in reference NPI. This interface is supported by OpenSS7 directly and using the NPI module described in NPI Conversion Module.

    This interface alone should be used for new inter-module service interfaces.

  • For applications interfaces and inter-module service interfaces for CONS (X.223), the only industry standard interface was specified by UNIX International as the Network Provider Interface (NPI) specified in reference NPI. This interface is supported by OpenSS7 directly and using the CON module described in CONS Module.

    This interface alone should be used by OSI applications, drivers and modules.

  • When porting legacy applications, drivers and modules to Linux, the Network Layer Interface (NLI) as specified in this document may be used both for application interface and for inter-module service interfaces.

Note that when porting legacy NLI applications to Linux using the interface specified in this document, that there are many variations in implementation of the NLI as modified by licensors of the Spider Systems, Ltd. implementation. These modifications are ofter incompatible. Some of the incompatibilities are hidden by an X.25 utility library described in NLI Library.


2 Model of the X.25 Packet Layer

The X.25 Packet Layer provides the means to manage the operation of the X.25 network. It is responsible for the routing and management of data exchange between network-user entities.

The NLI defines the services provided by the X.25 packet layer to the X.25 user at the boundary between the X.25 packet layer and the X.25 user entity. The interface consists of a set of messages defined as STREAMS messages that provide access to the X.25 packet layer services, and are transferred between the X.25 user entity and the X.25 packet layer provider.

These messages are of two types: ones that originate from the X.25 user, and other that originate from the X.25 packet layer. The messages that originate from the X.25 user make requests to the X.25 packet layer, or respone to an event of the X.25 packet layer. The messages that originate from the X.25 packet layer, are either confirmations of a request or are indications to the X.25 user that the event has occured. Figure 1 shows the model of the NLI.

Model of the NLI

Figure 1. Model of the NLI

The NLI allows the X.25 packet layer (as a STREAMS driver) to be configured with an X.25 user (as a STREAMS module) that conforms to the NLI. An X.25 user can also be a user program that conforms to the NLI and accesses the X.25 packet layer using putmsg(2s), putpmsg(2s), getmsg(2s), getpmsg(2s), and ioctl(2s) system calls.


3 NLI Services Definition

The features of the NLI are defined in termsof the services provided by the X.25 packet layer, and the individual messages that may flow between the X.25 user and the X.25 packet layer.

The services supported by the NLI are based on three related modes of communication, X.25 mode, non-X.25 mode, and CONS mode.


3.1 NLI Modes

Packet Level Features

  • permanent virtual circuits;
  • extended packet sequence numbering;
  • D-bit support;
  • packet transmission;
  • incoming calls barred;
  • outgoing calls barred;
  • one-way logical channel incoming;
  • one-way logical channel outgoing;
  • two-way logical channel;
  • non-standard default packet sizes;
  • non-standard default window sizes;
  • default throughput class assignement;
  • flow control parameter negotiation;
  • throughput class negotiation;
  • closed user group;
  • bilateral closed user group;
  • fast select;
  • fast select acceptance;
  • reverse charging;
  • reverse charging acceptance;
  • local charging prevention;
  • network user identification selection;
  • network user identification override;
  • RPOA selection;
  • called line address modification;
  • call redirection;
  • call deflection;
  • transit delay;
  • protection;
  • priority;
  • TOA/NPI addressing;
  • programmable facilities.

X.25 Facilities

  • fast select request;
  • fast select with unrestricted response;
  • fast select with restricted response;
  • reverse charging;
  • packet size negotiation;
  • window size negotiation;
  • closed user groups;
  • bilateral closed user groups;
  • network user identification;
  • RPOA selection;
  • called line address modification;
  • call redirection;
  • call charging;
  • programmable facilities;
  • DTE facility marker;
  • extended address;
  • throughput class;
  • transit delay;
  • expedited data;
  • protection;
  • priority;
  • call user data;
  • clear user data.

X.25 Operational Support

  • Q-bit support for X.29 services;
  • M-bit support for packet segmentation and reassembly;
  • D-bit for data delivery confirmation;
  • expedited data;
  • call charging;
  • called line address modification;
  • call deflection;
  • clear user data.

3.2 NLI Commands

CommandDescriptionSection
N_CIxcallfConnect Request/Indication.
N_CCxccnffConnect Response/Confirmation.
N_DataxdatafData.
N_DAckxdatacfData Acknowledgement.
N_EDataxeadatafExpedited Data.
N_EAckxedatacfExpedited Data Acknowledgement.
N_RIxrstfReset Request/Indication.
N_RCxrscfReset Response/Confirmation.
N_DIxdiscfDisconnect Request/Indication.
N_DCxdcnffDisconnect Confirmation.
N_AbortxabortfAbort Indication.
N_XlistenxlistenfListen Request/Response.
N_XelistenxlistenfExtended Listen Request/Response.
N_XcanlisxcanlisfListen Cancel Request/Response.
N_PVC_ATTACHpvcattfPVC Attach.
N_PVC_DETACHpvcdetfPVC Detach.

3.3 NLI Data Structures


3.3.1 Addresses

In call requests and responses, it is necessary to specify the X.25 addresses associated with the connection. These addresses consist of the called, calling and responding addresses. A common structure is used for these addresses. The addressing format used by this stricture provides the following information:

  • the subnetwork (data link) on which outgoing Connect Requests are to be sent and on which incoming Connect Indications arrive;
  • Network Service Access Points (NSAP) and Subnetwork Point of Attachments (SNPA), or Data Terminal Equipment (DTE) addresses and Link Service Access Points (LSAP); and,
  • optional formats for the encoding of addresses (NSAP).

3.3.1.1 X.25 Address Format

Addresses are represent using an xaddrf structure. The xaddrf structure is formatted as follows:

#define NSAPMAXSIZE 20

struct xaddrf {
    union {
        uint32_t link_id;
        uint32_t sn_id;
    };
    unsigned char aflags;
    struct lsapformat DTE_MAC;
    unsigned char nsap_len;
    unsigned char NSAP;
};

The xaddrf structure contains the following members:

link_id

Holds the link number as a uint32_t. By default, link_id has a valud of ‘0xFF’. When link_id is ‘0xFF’, Solstice X.25 attempts to match the valled address with an entry in a routing configuration file. If it cannot find a match, it routes the call over the lowest numbered WAN link.

sn_id

Note that in some implementations, the sn_id field is declared as unsigned long; however, this causes complications for 32-bit applications running over a 64-bit kernel: i.e., it requires that the data model of the application be known to the kernel module and conversions be supported. Therefore, this field appears in the header file as the 32- vs. 64-bit agnostic uint32_t.

aflags

Specifies the options required (or used) by the subnetwork to encode and interpret addresses. It may have one of the following values:

NSAP_ADDR0x00NSAP is OSI-encoded NSAP address.
EXT_ADDR0x01NSAP is non-OSI-encoded extended address.
PVC_LCI0x02NSAP is a PVC number.
PVC_LCI0x02DTE_MAC is the LCI of a PVC.

When the NSAP field is empty, aflags takes the value zero (0).3

DTE_MAC

The DTE address, or LSAP as two BCD digits per byte, right justified, or the PVC_LCI as three BCD digits with two digits per byte, right justified. Holds the DTE address, the Medium Access Control plus Service Access Point (MAC+SAP) address or the LCI. This is binary. See lsapformat.

nsap_len

The length in semi-octets of the NSAP as two BCD digits per byte, right justified. This indicates the length of the NSAP, if any (and where appropriate), in semi-octets.

NSAP

The NSAP or address extension (see aflags) as two BCD digitis per byte, right justified. This carries the NSAP or address extension (see field aflags) when present as indicated by nsap_len. This is binary.


3.3.1.2 LSAP Address Format

The lsapformat structure is formatted as follows:.

#define LSAPMAXSIZE

struct lsapformat {
    unsigned char lsap_len;
    unsigned char lsap_add[LSAPMAXSIZE];
};

The fields in this structure are defined as follows:

lsap_len

This gives the length of the DTE address, the MAC+SAP address, or the LCI in semi-octets. For example for Ethernet, the length is always 14 to indicate the MAC (12) plush SAP (2). The SAP always follows the MAC address. The DTE can be up to 15 decimal digits unless X.25(88) and Type Of Address/Numbering Plan Identification (TOA/NPI) addressing is being used, in which case, it can be up to 17 decimal digits. For an LCI, the length is 3. The length of the DTE address or LSAP as two BCD digits per byte, right justified. An LSAP is always 14 digits long. A DTE address can be up to 15 decimal digtis unless X.25(88) and TOA/NPI addressing is used, in which case it can be up to 17 decimal digits. A PVC_LCI is 3 digits long.

lsap_add

This holds the DTE, MAC+SAP or LCI, when present, as indicated by lsap_len. This is binary. The DTE address, LSAP or PVC_LCI as two BCD digits per byte, right justified.

For TOA/NPI the TOA is:

00000Network-dependent number or unknown.
00011International number.
00102National number.
00113Network specific number (for use in private networks).
01004Complementary address without main address.
01015Alternative address.

NPI for other than Alternative address is:

00000Network-dependent number or unknown.
00011ITU-T Recommendation E.164 (digital).
00102ITU-T Recommendation E.164 (analog).
00113ITU-T Recommendation X.121.
01004ITU-T Recommendation F.69 (telex numbering plan).
01015Private number plan (for private use only).

NPI when TOA is Alternative Address is:

00000Character string coding to ISO/IEC 646.
00011OSI NSAP address coded per X.213/ISO 8348.
00102MAC address per IEEE 802.2/ISO/IEC 8802:1998.
00113Internet Address per RFC 1166. (i.e. an IPv4 address).

3.3.2 CONS Quality of Service Parameters

Negotiable X.25 facilities are supported by the PLP driver. This section describes the request and negotiation of these facilities, and the data structures used by the NLI primitives.

The facilities are broken down into two groups:

  • those required for Connection-Oriented Network Service (CONS) support, and
  • those requried for non-OSI procedures (X.29, for example).

The CONS quality of service (QOS) parameters supported are the following:

  • Throughput Class
  • Minimum Throughput Class
  • Target Transit Delay
  • Maximum Acceptable Transit Delay
  • Use of Expedited Data
  • Protection
  • Receipt Acknolwedgement

CONS-related quality of service parameters are defined in the qosformat structure. The qosformat structure is formatted as follows:

#define MAX_PROT 32

struct qosformat {
    unsigned char reqtclass;
    unsigned char locthroughput;
    unsigned char remthroughput;
    unsigned char reqminthruput;
    unsigned char locminthru;
    unsigned char remminthru;
    unsigned char reqtransitdelay;
    unsigned short transitdelay;
    unsigned char reqmaxtransitdelay;
    unsigned char acceptable;
    unsigned char reqpriority;
    unsigned char reqprtygain;
    unsigned char reqprtykeep;
    unsigned char prtydata;
    unsigned char prtygain;
    unsigned char prtykeep;
    unsigned char reqlowprtydata;
    unsigned char reqlowprtygain;
    unsigned char reqlowprtykeep;
    unsigned char lowprtydata;
    unsigned char lowprtygain;
    unsigned char lowprtykeep;
    unsigned char protection_type;
    unsigned char prot_len;
    unsigned char lowprot_len;
    unsigned char protection[MAX_PROT];
    unsigned char lowprotection[MAX_PROT];
    unsigned char reqexpedited;
    unsigned char reqackservice;
    struct extraformat xstras;
};

The qosformat structure has the following members:

reqtclass

When non-zero, conveys that throughput negotiation is selected.

locthroughput

Contains the four-bit throughput encoding for the local to remote direction.

remthroughput

Contains the four-bit throughput encoding for the remote to local direction.

reqminthruput

When non-zero, conveys that minimum throughput negotiation is selected.

locminthru

When reqminthruput is non-zero, conveys the four-bit throughput encoding for the local to remote direction.

remminthru

When reqminthruput is non-zero, conveys the four-bit throughput encoding for the remote to local direction.

reqtransitdelay

When non-zero, conveys that target transit delay negotiation is selected.

transitdelay

When reqtransitdelay is non-zero, conveys the 16-bit value. In a Connect Confirmation, the value of the selected transit delay is placed in this field and is non-zero.

reqmaxtransitdelay

When non-zero, conveys that maximum acceptable transit delay negotiation is selected.

acceptable

When reqmaxtransitdelay is non-zero, conveys the 16-bit value of the maximum acceptable transit delay.

Note: Transit delay selection applies only to Connect Requests. There is no transit dleay QOS parameter in a Connect Response. The correct response when the indicated QOS is unattainable is to make a Disconnect Request. In a Connect Confirmation, the value of the selected transit delay is placed in the transitdelay field when such negotiation takes place.

reqpriority

When non-zero, conveys that data priority negotiation is selected.

reqprtygain

When non-zero, conveys that gain priority negotiation is selected.

reqprtykeep

When non-zero, conveys that keep priority negotiation is selected.

prtydata

When reqpriority is non-zero, contains the 8-bit priority for sending data.

prtygain

When reqprtygain is non-zero, contains the 8-bit priority for gaining a connection.

prtykeep

When reqprtykeep is non-zero, contains the 8-bit priority for keeping a connection.

reqlowprtydata

When non-zero, conveys that data low priority negotiation is selected. This field is only valid on Connect Requests/Indications.

reqlowprtygain

When non-zero, conveys that gain low priority negotiation is selected. This field is only valid on Connect Requests/Indications.

reqlowprtykeep

When non-zero, conveys that keep low priority negotiation is selected. This field is only valid on Connect Requests/Indications.

lowprtydata

When reqlowprtydata is non-zero, contains the 8-bit priority for sending data. This field is only valid on Connect Requests/Indications.

lowprtygain

When reqlowprtygain is non-zero, contains the 8-bit priority to gain a connection. This field is only valid on Connect Requests/Indications.

lowprtykeep

When reqlowprtykeep is non-zero, contains the 8-bit priority to keep a connection. This field is only valid on Connect Requests/Indications.

protection_type

When non-zero, conveys that protection negotiation is selected. The field can be one of the following valuse:

ValueNameMeaning
1PRT_SRCSource address specific.
2PRT_DSTDestination address specific.
3PRT_GLBGlobally unique.
prot_len
lowprot_len

This field is only valid on Connect Requests/Indications.

protection
lowprotection

This field is only valid on Connect Requests/Indications.

reqexpedited

When non-zero, conveys that expedited data negotiation is selected. For Connect Indications, a non-zero value implies that the Expedited Data negotiation facility was present in the incoming call packet, and that its use was requested.

Note: Negotiation is a CONS procedure. When the facility is present and indicates non-use, use cannot be negotiated by Connect Responses. For a description of the use of the CONS_call field in Connect Requests and Connect Responses, see Connect Request/Indication, and Connect Response/Confirmation.

For incoming or outgoing non-CONS calls (denoted by the CONS_call flag set to zero (0)), Expedited Data negotiation is not required: interrupt data is always available in X.25. This means that this field is ignored on Connect Requests and Responses for non-CONS calls.

reqackservice

When non-zero, conveys that receipt confirmation negotiation is selected. For Connect Indications, a non-zero value implies that the Receipt Confirmation negotiation facility was present in the incoming call packet, and that its use was requested. This field can have one of the following values:

ConstantValueDescription
-0No receipt confirmation.
RC_CONF_DTE1Confirmation by the remote terminal.
RC_CONF_APP2Confirmation by the remote application.

In the case of receipt confirmation by the remote DTE, no acknowledgements are expected or given over the X.25 service interface. In the case of receipt confirmation by the remote application, there is a one-to-one corrrespondence between D-bit data and acknowledgements, with one data acknowlegement being received or sent for each D-bit data packet sent or received over the X.25 service interface.

xstras

3.3.3 Non-OSI X.25 Facilities

Although these are non-OSI facilities, they are also negotiable with CONS. For those NLI applications that require them, the non-OSI facilities supported are as follows:

  • non-OSI extended addressing;
  • X.25 fast select request/indication with no restriction on response;
  • X.25 fast select reqeust/indication with restriction on response;
  • X.25 reverse charging;
  • X.25 packet size negotiation;
  • X.25 window size negotiation;
  • X.25 network user identification;
  • X.25 recognized private operating agency selection;
  • X.25 closed user groups;
  • X.25 call deflection; and,
  • X.25 programmable facilities.

Non-OSI X.25 Facilities are defined in the extraformat structure. The extraformat structure is formatted as follows:

#define MAX_NUI_LEN  64
#define MAX_RPOA_LEN  8
#define MAX_CUG_LEN   2
#define MAX_FAC_LEN  32
#define MAX_TARIFFS   4
#define MAX_CD_LEN   MAX_TARRIFS * 4
#define MAX_SC_LEN   MAX_TARRIFS * 4
#define MAX_MU_LEN   16
struct extraformat {
    unsigned char fastselreq;
    unsigned char restrictresponse;
    unsigned char reversecharges;
    unsigned char pwoptions;
    unsigned char locpacket;
    unsigned char rempacket;
    unsigned char locwsize;
    unsigned char remwsize;
    int nsdulimit;
    unsigned char nui_len;
    unsigned char nui_field[MAX_NUI_LEN];
    unsigned char rpoa_len;
    unsigned char rpoa_field[MAX_RPOA_LEN];
    unsigned char cug_type;
    unsigned char cug_field[MAX_CUG_LEN];
    unsigned char reqcharging;
    unsigned char chg_cd_len;
    unsigned char chg_cd_field[MAX_CD_LEN];
    unsigned char chg_sc_len;
    unsigned char chg_sc_field[MAX_SC_LEN];
    unsigned char chg_mu_len;
    unsigned char chg_mu_field[MAX_MU_LEN];
    unsigned char called_add_mod;
    unsigned char call_redirect;
    struct lsapformat called;
    unsigned char call_deflect;
    unsigned char x_fac_len;
    unsigned char cg_fac_len;
    unsigned char cd_fac_len;
    unsigned char fac_field[MAX_FAC_LEN];
};

The extraformat structure has the following members:

fastselreq

For non-OSI services (e.g. X.29), if the X.25 facility fast select is to be requested or indicated, this field is non-zero. For CONS, the use of fast select is optional.

restrictresponse

If the resonse to a Connect Request or Indication is to be a Diconnect Indiciation, this filed is non-zero.

reversecharges

If reverse charging is requested or indicated for a connection, this field is non-zero. The configuration mod bit SUB_REVCHARGE has an impact on whether reverse charging is indicated, since it is possible to select a per-subnetwork policy for reciept of reverse charging.

pwoptions

This field is used to indicate per-circuit options. The field is a bitwise OR of zero or more of the following values:

NameValueMeaning when set.
NEGOT_PKT0x01Packet size negotiation permitted.
NEGOT_WIN0x01Window size negotiation permitted.
ASSWERN_HWM0x01Assert concatentaiton limit.

The field is defined as follows:

#define NEGOT_PKT       0x01
#define NEGOT_WIN       0x02
#define ASSERT_HWM      0x04

The field is used for two reasons:

  1. The X.25 software always indicates the values of the window and packet sizes operating on the virtual circuit. The field pwoptions for an incoming call indicates whether these values are negotiable.
  2. In Connect Request/Response message, the NLI user can set nsdulimit, the limit value for packet concatentation by the X.25 level, to a value different from the limit in the subnetwork configuration database. It is not a negotiable option, so whatever the user requests is used.
locpacket

When non-zero, contains the local to remote direction packet size. The default value, DEF_X25_PKT, is seven (7).

rempacket

When non-zero, contains the remote to local direction packet size. The default value, DEF_X25_PKT, is seven (7).

locwsize

When non-zero, contains the local to remote direction window size. The default value, DEF_X25_WIN, is two (2).

remwsize

When non-zero, contains the remote to local direction window size. The default value, DEF_X25_WIN, is two (2).

nsdulimit

When non-zero, and the appropriate bit is set in the pwoptions field, this field is used as the specified concatentaiton limit.

nui_len

Valid in Connect Requests and Connect Responses, when non-zero, specifies the length of the nui_field in octets. The Network User Identification facility is not available on 1980 X.25 networks.

nui_field

Contains the Network User Identification (NUI) octets of length nui_len.

rpoa_len

Valid in Connect Requests only. When non-zero, the RPOA DNIC information is suppplied in the rpoa_field field and the semi-octets in the field are of this length.

rpoa_field

Contains the Recognized Private Operating Agency (RPOA) semi-octets of length rpoa_len.

cug_type

Valid in Connect Requests and Connect Indications only, this field, when non-zero, is 1 for Closed User Group (CUG) and 2 for Bilateral CUG (two members only).

Note: Incoming CUG facilities are assumed to have been validated by the network. No further cehcking is performed.

cug_field

Contains the Closed User Group (CUG) semi-octets of length up to four (4) semi-octets for CUG and four semi-octets (4) for BCUG (Bilateral CUG).

reqcharging

When non-zero in a Connect Request of Connect Indication, call charging is requested; in a Disconnect Indication of Disconnect Confirmation, the six fields below will give the charging information.

chg_cd_len

When non-zero, conveys the length of the chg_cd_field field.

chg_cd_field

Conveys the call duration.

chg_sc_len

When non-zero, conveys the length of the chg_sc_field field.

chg_sc_field

Conveys the segment count.

chg_mu_len

When non-zero, conveys the length of the chg_mu_field field.

chg_mu_field

Conveys the monetary unit.

called_add_mod

When non-zero, conveys the reason value for call modification.

call_redirect

When non-zero, conveys the reason for call redirection.

called

When call_redirect is non-zero, conveys the orignalling called DTE address.

call_deflect

Valid in the Disconnect Request and Disconnect Indication, when non-zero, conveys the reason for call deflection. The deflected field in the Disconnect Request or Indication conveys the DTE address, and if required, the NSAP address to which the call is to be deflected.

x_fac_len

Valid in Connect Requests and Connect Indications only, when non-zero, provides the length of the explicit facility ecnoded strings for X.25 facilities.

cg_fac_len

Valid in Connect Requests and Connect Indiciations only, when non-zero, provides the length of the explicit facility encoded strings for non-X.25 facilities for the calling network.

cd_fac_len

Valid in Connect Requests and Connect Indiciations only, when non-zero, provides the length of the explicit facility encoded strings for non-X.25 facilities for the called network.

fac_field

When x_fac_len, cg_fac_len or cd_fac_len are non-zero, contains the X.25 facilities, non-X.25 facilities for the calling network, and/or non-X.25 facilities for the called network.

Note: The contents of this field, if supplied, are not validated or acted upon by the code. The X.25 facilities are inserted at the end of any other X.25 facilities that are passed in the Connect Request/Indication (for example, packet or window sizes). If any non-X.25 facilities are supplied, the appropriate marker is inserted before the supplied facilities.


4 NLI Primitives


4.1 Connect Request/Indication

Format

The Connect Request and Connect Indication use the xcallf structure. The control part of the message consists of one M_PROTO message block containing the xcallf structure. The data part of the message consists of zero or one M_DATA message blocks containing the Call User Data (if any).

The xcallf structure is formatted as follows:

struct xcallf {
    unsigned char xl_type;
    unsigned char xl_command;
    int conn_id;
    unsigned char CONS_call;
    unsigned char negotiate_qos;
    struct xaddrf calledaddr;
    struct xaddrf callingaddr;
    struct qosformat qos;
};

Usage

The Connect Request or Indication message primitive, N_CI, is used by the NS user to request a outgoing connection, or by the NS provider to indicate an incoming connection. The control part of the message consists of one M_PROTO message block, and contains the xcallf structure. The data part of the message consists of zero or one M_DATA message blocks containing the Call User Data (CUD) when supplied.

Parameters

The xcallf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_CI, for both Connect Requests and Connect Indications.

conn_id

This field is used only for Connect Indications. When an NS user Stream is listening, multiple incoming Connect Indications can be pending. This field indicates the connection identifier for the current Connect Indication for use by the NS user when responding to this Connection Indication with either a Connect Response or a Disconnect Request message.

CONS_call

Either X.25 or CONS procedures4 can be used for calls. When non-zero, this field indicates that CONS procedures are to be used. When zero, this field indicates that X.25 procedures are to be used.

negotiate_qos

QOS parameters can be negotiated by the peer or left at default values. When non-zero, this field specifies or indicates that QOS parameters are being negotiated by the NS user or NS user peer and the pertinent ranges are provided in the qos member. When zero, this field specifies and indicates that default values are to be used for the NS user or were indicated by the NS user peer.

calledaddr

Conveys the called address. For outgoing Connect Requests, this is the remote address to which the call is to be connected. For incoming Connect Indications, this is the local address to which the call was initiated.

callingaddr

Conveys the calling address. For outgoing Connect Requests, this is the local address from which the call is to be connected. For incoming Connect Indications, this is the remote address from which the call was initiated.

qos

Conveys the quality of service parameters and CONS an non-CONS facilities that are requested or indicated.

State

Response

When the Connect Request is issued by the NS user, the expected response from the NS provider is a Connect Conformation or a Disconnect Indication.

When the Connect Indication is issued by the NS provider, the expected response from the NS user is a Connect Response or a Disconnect Request.

Equivalence

The Connect Request message primitive is equivalent to the N_CONN_REQ primitive of the NPI; the Connect Indication, the N_CONN_IND.


4.2 Connect Response/Confirmation

Format

The Connect Response and Connect Confirmation use the xccnff structure. The control part of the message consists of one M_PROTO message block containing the xccnff structure. The data part of the message consists of zero or one M_DATA message blocks containing the Call User Data (if any).

The xccnff structure is formatted as follows:

struct xccnff {
    unsigned char xl_type;
    unsigned char xl_command;
    int conn_id;
    unsigned char CONS_call;
    unsigned char negotiate_qos;
    struct xaddrf responder;
    struct qosformat rqos;
};

Usage

The Connect Response or Confirmation message primitive, N_CC, is used by the NS user to response to an incoming connection, or by the NS provider to confirm an outgoing connection. The control part of the message consists of one M_PROTO message block, and contains the xccnff structure. The data part of the message consists of zero or one M_DATA message block containing the Call User Data (CUD) when supplied.

Parameters

The xccnff structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_CC, for both Connect Response and Connect Confirmation.

conn_id

This field is only used for Connect Responses. When an NS user Stream is listening, multiple incoming Connect Indications can be pending. This field specifies the connection identifier from the Connection Indication to which the NS user is responding.

CONS_call

Either X.25 or CONS procedures5 can be used for calls. When non-zero, this field indicates that CONS procedures are to be used. When zero, this field indicates that X.25 procedures are to be used.

negotiate_qos

QOS parameters can be negotiated by the peer or left at default values. When non-zero, this field specifies or indicates that QOS parameters are being negotiated by the NS user or NS user peer and the pertinent ranges are provided in the rqos member. When zero, this field specifies and indicates that default values are to be used for the NS user or were indicated by the NS user peer.

responder

Conveys the responding address. For Connect Responses, this is the local address that is responding to the incoming call. For Connect Confirmations, this is the remote address that responded to the outgoing call.

rqos

Conveys the negotiated quality of service parameters and CONS an non-CONS facilities in response or confirmation.

State

Response

No response is expected when either the NS user or NS provider issue this primitive.

Equivalence

The Connect Response message primitive is equivalent to the N_CONN_RES primitive of the NPI; the Connect Confirmation, the N_CONN_CON.


4.3 Data

Format

The Data message uses the xdataf structure. The control part of the message consists of one M_PROTO message block, and contains the xdataf structure. The data part of the message consists of one or more M_DATA message blocks containing the local or remote NS user data (NSDU).

The xdataf structure is formatted as follows:

struct xdataf {
    unsigned char xl_type;
    unsigned char xl_command;
    unsigned char More;
    unsigned char setDbit;
    unsigned char setQbit;
};

Usage

The Data message primitive, N_Data, is used to transfer NS user data to or from the NS user. The control part of the message consists of one M_PROTO message block, and contains the xdataf structure. The data part of the message consists of one or more M_DATA message blocks containing the local or remote NS user data (NSDU).

Parameters

The xdataf structure contains the following members:

xl_type

Always XL_DAT.

xl_command

Always N_Data, for both Data Request and Data Indication.

More

When non-zero, this field conveys that a subsequent N_Data message primitive will contain additional data belonging to the same NSDU. When zero, this field conveys that the data contained in the message primitive completes an NSDU.

setDbit

Conveys that the D-bit is to be (or was) associated with the NSDU. When the data portion represents part of an NSDU, the bit must be set or clear on each request or indication belonging to the same NSDU.

setQbit

Conveys that the Q-bit is to be (or was) associated with the NSDU. When the data portion represents part of an NSDU, the bit must be set or clear on each request or indication belonging to the same NSDU.

State

This message primitive is only valid during the data transfer phase.

Response

No response is expected when either the NS user or NS provider issue this primitive, unless the D-bit is set, in which case a Data Acknowledgement response is expected from the NS provider or NS user, respectively.

Equivalence

The Data message primitive is equivalent to the N_DATA_REQ and N_DATA_IND primitives of the NPI.


4.4 Data Acknowledgement

Format

The Data Acknowledgement message uses the xdatacf structure. The control part of the message consists of one M_PROTO message block, and contains the xdatacf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The xdatacf structure is formatted as follows:

struct xdatacf {
    unsigned char xl_type;
    unsigned char xl_command;
};

Usage

The Data Acknowledgement message primitive, N_DAck, is used to request or indicate acknolwedgement of data. The control part of the message consists of one M_PROTO message block, and contains the xdatacf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

Parameters

The xdatacf structure contains the following members:

xl_type

Always XL_DAT.

xl_command

Always N_DAck.

State

This message primitive is only valid during the data transfer phase.

Response

When receipt confirmation from the remote application is active on a VC, this message primitive is used to acknowledge a previous N_DAck request or indication that had the D-bit set. There is a one-to-one correspondence between D-bit data and acknowledgements, with one Data Acknowledgement being conveyed for each Data message primitive conveyed. The Data message primitive acknowledged is always the oldest outstanding Data message primitive that requested acknowledgement.

For CONS calls, if receipt acknowledgement was negotiated on the connection, then an acknowledgement is pending for each Data primitive conveyed. However, to be compatible with previous releases of the NPI, the value of the reqackservice field in the qos structure can be set to request that the D-bit signifies receipt confirmation by the remote DTE only, thus ensuring that no acknowledgements are expected or given.

For non-CONS calls, only when the reqackservice field in the qos structure has been set to the appropriate value will the Data Acknolwedgement procedures apply for an D-bit Data requested or indicated. Otherwise, no acknowledgement is expected or given.

Equivalence

The Data Acknowledgement message primitive is equivalent to the N_DATACK_REQ and N_DATACK_IND primitives of the NPI.


4.5 Expedited Data

Format

The Expedited Data message uses the xedataf structure. The control part of the message consists of one M_PROTO message block, and contains the xedataf structure. The data part of the message consists of one or more M_DATA message blocks containing the local or remote expedited NS user data (ENSDU).

The xedataf structure is formatted as follows:

struct xedataf {
    unsigned char xl_type;
    unsigned char xl_command;
};

Usage

The Expedited Data message primitive, N_EData, is used to transfer expedited NS user data to or from the NS user. The control part of the message consists of one M_PROTO message block, and contains the xedataf structure. The data part of the message consists of one or more M_DATA message blocks containing the local or remote expedited NS user data (ENSDU).

The Expedited Data message primitive, N_EData, is used when expedited data, carried by an X.25 interrupt packet, corsses the X.25 NLI service interface from NS provider to user or NS user to provider. The Expedited Data message is a confirmed primitive and must be acknowledged before another expedited data unit can be requested or indicated.

Parameters

The xedataf structure contains the following members:

xl_type

Always XL_DAT.

xl_command

Always N_EData.

State

This message primitive is only valid during the data transfer phase.

Response

When NS user or provider issues this primtive it expectes an Expedited Data Acknowledgement message primitive in reponse. The Expedited Data message is a confirmed primitive and must be acknowledged before another expedited data unit can be requested or indicated.

Equivalence

The Expedited Data message primitive is equivalent to the N_EXDATA_REQ and N_EXDATA_IND primitives of the NPI.


4.6 Expedited Data Acknowledgement

Format

The Expedited Data Acknowledgement message uses the xedatacf structure. The control part of the message consists of one M_PROTO message block, and contains the xedatacf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The xedatacf structure is formatted as follows:

struct xedatacf {
    unsigned char xl_type;
    unsigned char xl_command;
};

Usage

The Expedited Data Acknowledgement message primitive, N_EAck, is used to request or indicate acknolwedgement of expedited data. The control part of the message consists of one M_PROTO message block, and contains the xedatacf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

Parameters

The xedatacf structure contains the following members:

xl_type

Always XL_DAT.

xl_command

Always N_EAck.

State

This message primitive is only valid during the data transfer phase.

Response

The Expedited Data Acknolwedgement message primitive is issued only in confirmation to the Expedited Data message primitive. When an Expedited Data message primitive is delivered to the NS user or provider, the NS provider or user, respectively, must acknowledged the expedited data.

Equivalence

The Expedited Data Acknowledgement message primitive has no equivalent in the NPI.


4.7 Reset Request/Indication

Format

The Reset Request and Reset Indication use the xrstf structure. The control part of the message consists of one M_PROTO message block containing the xrstf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The xrstf structure is formatted as follows:

struct xrstf {
    unsigned char xl_type;
    unsigned char xl_command;
    unsigned char originator;
    unsigned char reason;
    unsigned char cause;
    unsigned char diag;
};

Usage

The Reset Request or Indication message primitive, N_RI, is used by the NS user to request reset of the connection, or by the NS provider to indicate a remote reset. The control part of the message consists of one M_PROTO message block, and contains the xrstf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The X.25 cause and diagnostic octets, cause and diag, are conveyrs, as well as the CONS originator and reason codes, which are mapped from the cause and diag. A Reset Request on a non-CONS call can specify a non-zero cause code. This has no effect for a CONS call.

Parameters

The xrstf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_RI.

originator

For a CONS call, contains the CONS originator mapped from the X.25 cause and diagnostic. This field can have one of the following values:

ConstantValueDescription
NS_UNKNOWN0Originator is unknown.
NS_USER1Originator is the NS user.
NS_PROVIDER2Originator is the NS provider.
reason

For a CONS call, contains the CONS reason, mapped from the X.25 cause and diagnostic. This field can have one of the following values when the originator is NS_PROVIDER:

ConstantValueDescription
NS_RUNSPECIFIED233Unspecified reason.
NS_RCONGESTION234Congestion.

The field can have the following values when the originator is NS_USER:

ConstantValueDescription
NS_RESYNC250Resynchronization.

The field can have the following values when the originator is NS_UNKNOWN:

ConstantValueDescription
NS_UNKNOWN0Unspecified reason.
cause

Conveys the X.25 cause octet associated with the reset.

diag

Conveys the X.25 diagnostic octet associated with the reset.

State

This message primitive is valid in the data transfer phase.

Response

A Reset Request and Reset Indication message primitive is an acknowledged service. The NS user expects a Reset Confirmation primitive in response to a Reset Request; the NS provide, a Reset Response primitive in reesponse to a Reset Indication.

A collision between a Reset Indication and a Reset Request is taken to acknolwedge the Reset Request and no Reset Confirmation is then issued.

Equivalence

The Reset Request message primitive is equivalent to the N_RESET_REQ of the NPI; the Reset Indication, N_RESET_IND.


4.8 Reset Response/Confirmation

Format

The Reset Response and Reset Confirmation use the xrscf structure. The control part of the message consists of one M_PROTO message block containing the xrscf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The xrscf structure is formatted as follows:

struct xrscf {
    unsigned char xl_type;
    unsigned char xl_command;
};

Usage

The Reset Response or Confirmation message primitive, N_RC, is used by the NS user to respond to a Reset Indication for the connection, or by the NS provider to confirm a Reset Request. The control part of the message consists of one M_PROTO message block, and contains the xrscf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

Parameters

The xrscf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_RC.

State

This message primitive is valid in the data transfer phase.

Response

The Reset Response message primitive is used by the NS user to respond to and acknowledge a previous Reset Indication message primitive from the NS provider. The Reset Confirmation message primitive is used by the NS provider to respond to and acknowledge a previous Reset Request message primitive from the NS user.

Equivalence

The Reset Response message primitive is equivalent to the N_RESET_RES of the NPI; the Reset Confirmation, N_RESET_CON.


4.9 Disconnect Request/Indication

Format

The Disconnect Request and Disconnect Indication use the xdiscf structure. The control part of the message consists of one M_PROTO message block containing the xdiscf structure. The data part of the message consists of zero or one M_DATA message blocks containing the Clear User Data (if any).

The xdiscf structure is formatted as follows:

struct xdiscf {
    unsigned char xl_type;
    unsigned char xl_command;
    unsigned char originator;
    unsigned char reason;
    unsigned char cause;
    unsigned char diag;
    int conn_id;
    unsigned char indicated_qos;
    struct xaddrf responder;
    struct xaddrf deflected;
    struct qosformat qos;
};

Usage

The Disconnect Request or Indication message primitive, N_DI, is used by the NS user to reject an incoming connection or disconnect an existing connection, or by the NS provider to reject an outgoing connection or disconnect an existing connection. The control part of the message consists of one M_PROTO message block, and contains the xdiscf structure. The data part of the message consists of zero or one M_DATA message blocks containing the Clear User Data (CUD) when supplied.

The X.25 cause and diagnostic octets, cause and diag, are presented, as well as the CONS originator and reason codes mapped from the X.25 cause and diagnostic. A Disconnect Request for a non-CONS call can specify a non-zero cause code. This has no effect for a CONS call.

Parameters

The xdiscf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_DI.

originator

For a CONS call, contains the CONS originator (NS user, NS provider, or unknown), mapped from the X.25 cause and diagnostic. This field can have one of the following values:

ConstantValueDescription
NS_UNKNOWN0Originator is unknown.
NS_USER1Originator is the NS user.
NS_PROVIDER2Originator is the NS provider.
reason

For a CONS call, contains the CONS reason, mapped from the X.25 cause and diagnostic. This field can have one of the following values when the originator is NS_PROVIDER:

ConstantValueDescription
NS_GENERIC224General.
NS_DTRANSIENT225Disconnect, transient.
NS_DPERMANENT226Disconnect, permanent.
NS_TUNSPECIFIED227Reject, unspecified, transient.
NS_PUNSPECIFIED228Reject, unspecified, permanent.
NS_QOSNATRANSIENT229Reject, QOS unavailable, transient.
NS_QOSNAPERMANENT230Reject, QOS unavailable, permanent.
NS_NSAPTUNREACHABLE232Reject, NSAP unreachable, transient.
NS_NSAPPUNREAHCABLE235Reject, NSAP unreachable, permanent.

The field can have the following values when the originator is NS_USER:

ConstantValueDescription
NU_GENERIC240General.
NU_DNORMAL241Disconnect, normal.
NU_DABNORMAL242Disconnect, abnormal.
NU_DINCOMPUSERDATA243Disconnect, incomprehensible user data.
NU_TRANSIENT244Reject, transient.
NU_PERMANENT245Reject, permanent.
NU_QOSNATRANSIENT246Reject, QOS unavailable, transient.
NU_QOSNAPERMANENT247Reject, QOS unavailable, permanent.
NU_INCOMPUSERDATA248Reject, Call User Data facility.
NU_BADPROTID249Reject, Bad protocol identifier.
cause

Conveys the X.25 cause octet associated with the disconnect.

diag

Conveys the X.25 diagnostic octet associated with the disconnect.

conn_id

When a Disconnect Request is used to refuse and incoming connection, this field contains the conn_id from the corresponding Connect Indication message primitive.

indicated_qos

When non-zero, conveys that facilities and quality of service paraemters are being indicated.

responder

Conveys the responding address. This is the local responding address in a Disconnect Request used to refuse an incoming call, and a remote responding address in a Disconnect Indication refusing an outgoing call.

deflected

When the call_deflect field of the associated qos structure is non-zero, this field conveys the deflected address. The deflected address is the address of the remote station to which the call is being deflected. This is set by the NS user when deflecting a call with a Disconnect Request refusing an incoming connection; and by the NS provider when an outgoing call has been deflected.

qos

Conveys the CONS quality of service parameters and non-OSI facilities associated with the disconnect. This is used currently for the charging information when an existing connection is disconnected, and for the deflection facility when an incoming or outgoing call is being deflected.

State

This primitive is valid in the data transfer phase; it is also valid in the incoming or outgoing connecting phase. The call moves to the disconnect phase.

Response

This primitive is valid in response to a previously sent Connect Request or received Connect Indication message primitive; or, to simply request or indicate disconnection of an existing connection.

When an existing connection is disconnect with a Disconnect Request by the NS user, the NS user expects a Disconnect Confirmation to acknowledge the disconnect. All other message should be discarded from the Stream until the Disconnect Confirmation is received.

When a Disconnect Indication is issued by the NS provider, all messages sent downstream except Connect Request or Connect Response messages are silently discarded.

A disconnect collision can occur, where Disconnect Request and a Disconnect Indication messages collide. In this case, the Disconnect Indication messages is taken as a confirmation and no Disconnect Confirmation message should be expected by the NS user.

Equivalence

The Disconnect Request message primitive is equivalent to the N_DISCON_REQ of the NPI; the Disconnect Indication, N_DISCON_IND.


4.10 Disconnect Confirmation

Format

The Disconnect Confirmation uses the xdcnff structure. The control part of the message consists of one M_PROTO message block, containing the xdcnff structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The xdcnff structure is formatted as follows:

struct xdcnff {
    unsigned char xl_type;
    unsigned char xl_command;
    unsigned char indicated_qos;
    struct qosformat qos;
};

Usage

The Disconnect Confirmation message primitive, N_DC, is used to confirm a previous Disconnect Request and provide charging information facilities associated with a previously established call. The control part of the message consists of one M_PROTO message block, containing the xdcnff structure. There is no data part (M_DATA message blocks) associated with this message primitive.

Parameters

The xdcnff structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_DC.

indicated_qos

When non-zero, conveys that CONS quality of service parameters and non-OSI facilities are indicated.

qos

Conveys the facilities indicated. This is only used on a Disconnect Confirmation to indicate the charging information facility.

State

This primitive is valid in the disconnecting phase.

Response

This message primitive is only issued by the NS provider. No response is expected when the NS provider issues this primitive.

Equivalence

The Disconnect Confirmation message primitive has no equivalent in NPI.


4.11 Abort Indication

Format

The Abort Indication uses the xabortf structure. The control part of the message consists of one M_PROTO message block containing the xabortf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The xabortf structure is formatted as follows:

struct xabortf {
    unsigned char xl_type;
    unsigned char xl_command;
};

Usage

The Abort Indication message primtiive is used by the X.25 driver in lieue of a Disconnect Indication, when there is insufficient resources to generate a Disconnect Indication. Therefore, some NS providers may never issue this message primitive. Nevertheless, the NS user must be prepared to receive this message primitive in liueue of a Disconnect Indication. The control part of the message consists of one M_PROTO message block containing the xabortf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

Parameters

The xabortf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_Abort.

State

This message primitive is only valid in the data transfer phase. The call moves to the disconnected phase.

Response

This message primitive is only issued by the NS provider. No response is expected when the NS provider issues this primitive.

Equivalence

The Abort Indication message primitive is equivalent to the N_DISCON_IND of the NPI.


4.12 Listen Request/Response

Format

The Listen Request and Listen Response use the xlistenf structure. The control part of the message consists of one M_PROTO or M_PCPROTO message block, and contains the xlistenf structure. The data part of the message consists of one or more M_DATA message blocks containing the call user data and address of interest.

The xlistenf structure is formatted as follows:

struct xlistenf {
    unsigned char xl_type;
    unsigned char xl_command;
    int lmax;
    int l_result;
};

The M_DATA message blocks are formatted as follows:

struct lcud {
    unsigned char l_cumode;
    unsigned char l_culength; /* octets */
    unsigned char l_cubytes[0];
    /* followed by l_culength bytes */
};
struct ladd {
    unsigned char l_mode;
    unsigned char l_type;
    unsigned char l_length; /* semi-octets */
    unsigned char l_add[0];
    /* followed by ((l_length+1)>>1) bytes
       containing l_length semi-octets. */
};

Usage

The Listen Request or Response is used when an NS user wishes to register interest in incoming calls and the NS provider acknowledges the request. The control part of the message consists of one M_PROTO or M_PCPROTO message block, and contains the xlistenf structure. The data part of the message consists of one or more M_DATA message blocks containing the call user data and address of interest.

The Listen Request queue is ordered in terms of the amount of listen data supplied. The more a Listen Request asks for, the higher its place in the queue. Connect Indications are sent to the listener whose listening criteria are best matched.

Privileged users can ask for a Listen Request to be placed at the front of the queue, regardless of the amount of listen data supplied. To do this, the Listen Request should be sent as a M_PCPROTO message. This is achieved by setting the RS_HIPRI flag in putmsg(2s). Such requests are searched in the order in which they arrive.

The system adminstrator controls whether or not listening for incoming calls is a privileged operation. If listening is privileged, incoming calls will be sent only to on listen streams opened by a user with superuser privilege. This prevents other users accepting calls that may contain private information, passwords, and so on.

In systems where privileged and non-privileged listens are allowed:

  • Privileged listens have priority.
  • A matching but busy privileged listen prevents a search of any non-privileged listens.

Parameters

The xlistenf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_Xlisten.

lmax

Conveys the maximum number of outstanding Connect Indications that the listening Stream is willing to accept, for the addresses conveyed in the attached M_DATA message blocks.

Listen requests are cummulated but this field is not. The maximum number of outstanding Connect Indications will be reflected by the value of this field for the last successful Listen Request issued by the NS user.

l_result

Conveys the result of the Listen Request in a Listen Response message primitive. An error in the parameters or a lack of resources results in this flag being set to a non-zero value.

The M_DATA portion of the message contains the following members:

l_cumode

Specifies the type of matching. This field can have one of the following values:

ConstantValueDescription
X25_DONTCARE1Represents a wildcard.
X25_STARTSWITTH2Contains a prefix.
X25_IDENTITY3Contains an identity match.

Notes:

  1. When the l_cumode is set to X25_DONTCARE, the l_culength and l_cubytes fields are ommitted from the M_DATA message block.
l_culength

Specifies the length of the l_cubytes field in octets.

l_cubytes

Contains the bytes to be matched against the Call User Data (CUD).

l_mode

Specifies the type of matching. This field can have one of the following values:

ConstantValueDescription
X25_DONTCARE1Represents a wildcard.
X25_STARTSWITTH2Contains a prefix.
X25_IDENTITY3Contains an identity match.
X25_PATTERN4Contains a pattern.6

Notes:

  1. When the l_mode is set to X25_DONTCARE, the l_type, l_length and l_add fields are ommitted from the M_DATA message block.
  2. When the l_mode is set to X25_PATTERN, the l_add field can contain the wilcard digits ‘*’ and ‘?’ that have the same effect as these characters in regular expressions: that is, ‘*’ represents zero or more characters of any value, and ‘?’ represents single character of any value. The ‘*’ character is represented by the BCD digit 0xF and the ‘?’ character is represented by the BCD digit 0xE.
l_type

This field can have one of the following values:

ConstantValueDescription
X25_DTE1Contains an X.25 DTE (X.121) address.
X25_NSAP2Contains a CONS NSAP address.
l_length

Specifies the length of the l_add field in semi-octets. That is, the length of the l_add field in octets is: ‘((l_length+1)>>1)’. The maximum length for a DTE address is 15 or 17 semi-octets (that is, 8 or 9 octets) depending upon whether TOA/NPI addressing is used. The maximum length for an NSAP address is 20 semi-octets (that is, 10 octets).

l_add

Contains the bytes to be matched against the DTE address or the NSAP address.

Each semi-octet is a BCD representation. That is, digits in the range ‘0’ through ‘9’ are represented by 0x0 through 0x9 in the semi-octet position. The first digit occupies the high order nibble of the first octet; the second digit, the low order nibble of the first octet; the third digit, the high order nibble of the second octet; and so on. If l_length is odd, the low order nibble of the last octet is ignored.

When the l_mode field is X25_PATTERN, a semi-octet of 0xF represents a ‘*’ wildcard, and a semi-octet of 0xE represents a ‘?’ wildcard.

State

This message primitive is valid in the disconnected phase or during an incoming connecting phase.

Response

When an NS user issues a Listen Request, the NS user expects a Listen Response message primitive from the NS provider.

Equivalence

The Listen Request message primitive is equivalent to the N_BIND_REQ of the NPI; the Listen Response, N_BIND_ACK.


4.13 Extended Listen Request/Response

Format

The Extended Listen Request and Extended Listen Response use the xlistenf structure. The control part of the message consists of one M_PROTO or M_PCPROTO message block, and contains the xlistenf structure. The data part of the message consists of one or more M_DATA message blocks containing the call user data and address of interest.

The xlistenf structure is formatted as follows:

struct xlistenf {
    unsigned char xl_type;
    unsigned char xl_command;
    int lmax;
    int l_result;
};

The M_DATA message blocks are formatted as follows:

struct lcud {
    unsigned char l_cumode;
    unsigned char l_culength; /* octets */
    unsigned char l_cubytes[0];
    /* followed by l_culength bytes */
};
struct lsn {
    unsigned char l_snmode;
    unsigned char l_snlen;
    unsigned char l_snid[0];
    /* followed by l_snlen bytes */
};
struct ladd {
    unsigned char l_mode;
    unsigned char l_type;
    unsigned char l_length; /* semi-octets */
    unsigned char l_add[0];
    /* followed by ((l_length+1)>>1) bytes
       containing l_length semi-octets. */
};

Usage

The Extended Listen Request or Response is used when an NS user wishes to register interest in incoming calls and the NS provider acknowledges the request. The control part of the message consists of one M_PROTO or M_PCPROTO message block, and contains the xlistenf structure. The data part of the message consists of one or more M_DATA message blocks containing the call user data and address of interest.

Parameters

The xlistenf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_Xelisten.

lmax

Conveys the maximum number of outstanding Connect Indications that the listening Stream is willing to accept, for the addresses conveyed in the attached M_DATA message blocks.

Listen requests are cummulated but this field is not. The maximum number of outstanding Connect Indications will be reflected by the value of this field for the last successful Listen Request issued by the NS user.

l_result

Conveys the result of the Listen Request in a Listen Response message primitive. An error in the parameters or a lack of resources results in this flag being set to a non-zero value.

The M_DATA portion of the message contains the following members:

l_cumode

Specifies the type of matching. This field can have one of the following values:

ConstantValueDescription
X25_DONTCARE1Represents a wildcard.
X25_MATCH4Contains a pattern match.7

Notes:

  1. When the l_cumode is set to X25_DONTCARE, the l_culength and l_cubytes fields are ommitted from the M_DATA message block.
l_culength

Specifies the length of the l_cubytes field in octets.

l_cubytes

Contains the bytes to be matched against the Call User Data (CUD).

l_snmode

Specifies the matching mode. This field can have one of the following values:

ConstantValueDescription
X25_DONTCARE1Represents a wildcard.
X25_MATCH4Contains a pattern match.8

Notes:

  1. When the l_mode is set to X25_DONTCARE, the l_snlen and l_snid fields are ommitted from the M_DATA message block.
l_snlen
l_snid
l_mode

Specifies the type of matching. This field can have one of the following values:

ConstantValueDescription
X25_DONTCARE1Represents a wildcard.
X25_MATCH4Contains a pattern match.9

Notes:

  1. When the l_mode is set to X25_DONTCARE, the l_type, l_length and l_add fields are ommitted from the M_DATA message block.
l_type

This field can have one of the following values:

ConstantValueDescription
X25_DTE1Contains an X.25 DTE (X.121) address.
X25_NSAP2Contains a CONS NSAP address.
l_length

Specifies the length of the l_add field in semi-octets. That is, the length of the l_add field in octets is: ‘((l_length+1)>>1)’. The maximum length for a DTE address is 15 or 17 semi-octets (that is, 8 or 9 octets) depending upon whether TOA/NPI addressing is used. The maximum length for an NSAP address is 20 semi-octets (that is, 10 octets).

l_add

Contains the bytes to be matched against the DTE address or the NSAP address.

State

This message primitive is valid in the disconnected phase or during an incoming connecting phase.

Response

When an NS user issues a Listen Request, the NS user expects an Extended Listen Response message primitive from the NS provider.

Equivalence

The Extended Listen Request message primitive is equivalent to the N_BIND_REQ of the NPI; the Extended Listen Response, N_BIND_ACK.


4.14 Listen Cancel Request/Response

Format

The Listen Cancel Request and Listen Cancel Response use the xcanlisf structure. The control part of the message consists of one M_PROTO message block containing the xcanlisf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The xcanlisf structure is formatted as follows:

struct xcanlisf {
    unsigned char xl_type;
    unsigned char xl_command;
    int c_result;
};

Usage

The Listen Cancel Request message primitive is used by the NS user to cancel listening on any address. The Listen Cancel Request removes all listen addresses from the Stream. There is no way of cancelling a Listen Request on a particular address; this message is probably used when the use of the Stream is about to be changed by the NS user. The control part of the message consists of one M_PROTO message block containing the xcanlisf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

Parameters

The xcanlisf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_Xcanlis.

c_result

Conveys the result of the Listen Cancel Request in a Listen Cancel Response message primitive. An failure to cancel a listen request results in this flag being set to a non-zero value. A Listen Cancel Request may fail because no listen was in effect, or a Connect Indication is outstanding.

State

This message primitive is valid in the disconnected phase.

Response

When an NS user issues a Listen Cancel Request, the NS user expects a Listen Cancel Response message primitive from the NS provider.

Equivalence

The Listen Cancel Request message primitive is equivalent to the N_UNBIND_REQ of the NPI; the Listen Cancel Response, N_OK_ACK.


4.15 PVC Attach

Format

The PVC Attach uses the pvcattf structure. The control part of the message consists of one M_PROTO message block containing the pvcattf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The pvcattf structure is formatted as follows:

struct pvcattf {
    unsigned char xl_type;
    unsigned char xl_command;
    unsigned short lci;
    union {
        uint32_t link_id;
        uint32_t sn_id;
    };
    unsigned char reqackservice;
    unsigned char reqnsdulimit;
    int nsdulimit;
    int result_code;
};

Usage

The PVC Attach message primitive is used by the NS user when requesting an attachment of the Stream to a PVC. The NS provider uses the PVC Attach message primitive to acknolwedge a previous PVC Attach message primitive issued by the NS user. The control part of the message consists of one M_PROTO message block containing the pvcattf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

Parameters

The pvcattf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_PVC_ATTACH.

lci

Conveys the logical channel identifier (LCI) of the PVC.

link_id

Conveys the link identifier for the PVC. This is a Solstice X.25 specific field.

The link_id and sn_id fields are equivalent, with a slightly different name and format for Solstice X.25.

sn_id

Conveys the subnetwork identifier for the PVC. This is the non-Solstice X.25 specific field.

This field is sometimes specified as a unsigned long. It has been declared as an uint32_t to support compatibility of 32-bit applications running over a 64-bit kernel.

reqackservice

When non-zero, conveys that the receipt confirmation service is requested by the use of the D-bit. This field can have one of the following values:

ConstantValueDescription
-0No receipt confirmation.
RC_CONF_DTE1Confirmation by the remote terminal.
RC_CONF_APP2Confirmation by the remote application.

In the case of receipt confirmation by the remote station, no acknowledgements are expected or given over the X.25 NLI service interface. For receipt confirmation by the remote application, there is a one-to-one correspondence between D-bit data and acknolwedgements passing in opposite directions. One data acknowledgement is received or sent for each D-bit data packet sent or received over the X.25 NLI service interface.

reqnsdulimit

When non-zero, conveys that an NSDU concantenation limit is asserted and the nsdulimit field is valid.

nsdulimit

When non-zero, conveys the packet concatenation limit for NSDUs when the reqnsdulimit field is also non-zero.

result_code

When the PVC Attach message primitive is used by the NS provider to acknowledge a previous PVC Attach message primitive issued by the NS user, this field is non-zero when an error has been encountered that prevents the attachment of the PVC.

This field can have one of the following values:

ConstantValueDescription
PVC_SUCCESS0Operation was successful.
PVC_NOSUCHSUBNET1Subnetwork not configured.
PVC_CFGERROR2LCI not in range, no PVCs.
PVC_NODBELEMENTS3No database available.
PVC_PARERROR4Error in request parameters.
PVC_BUSY6PVC in non-attach state.
PVC_CONGESTION7Resources unavailable.
PVC_WRONGSTATE8State wrong for function.
PVC_NOPERMISSION9Inadequate permissions.
PVC_LINKDOWN10The link has gone down.
PVC_RMTERROR11No reponse from remote.
PVC_USRERROR12User interface error detected.
PVC_INTERROR13Internal error.
PVC_NOATTACH14Not attached yet.
PVC_WAIT15Wait code, not to user.

State

This message primitive is valid in the disconnected phase.

Response

When an NS user issues a PVC Attach, the NS user expects a PVC Attach message primitive from the NS provider in response.

Equivalence

The PVC Attach message primitive is equivalent to the N_CONN_REQ and N_CONN_CON of the NPI.


4.16 PVC Detach

Format

The PVC Detach uses the pvcdetf structure. The control part of the message primitive consists of one M_PROTO message block containing the pvcdetf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

The pvcdetf structure is formatted as follows:

struct pvcdetf {
    unsigned char xl_type;
    unsigned char xl_command;
    int reason_code;
};

Usage

The PVC Detach message primitive, N_PVC_DETACH, is used when an NS user wishes to detach from a currently attached PVC. The control part of the message primitive consists of one M_PROTO message block containing the pvcdetf structure. There is no data part (M_DATA message blocks) associated with this message primitive.

Parameters

The pvcdetf structure contains the following members:

xl_type

Always XL_CTL.

xl_command

Always N_PVC_DETACH.

reason_code

When the PVC Detach message primitive is used by the NS provider to acknowledge a previous PVC Detach message primitive issued by the NS user, this field is non-zero when an error has been encountered that prevents detaching the PVC.

This field can have one of the following values:

ConstantValueDescription
PVC_SUCCESS0Operation was successful.
PVC_NOSUCHSUBNET1Subnetwork not configured.
PVC_CFGERROR2LCI not in range, no PVCs.
PVC_NODBELEMENTS3No database available.
PVC_PARERROR4Error in request parameters.
PVC_BUSY6PVC in non-attach state.
PVC_CONGESTION7Resources unavailable.
PVC_WRONGSTATE8State wrong for function.
PVC_NOPERMISSION9Inadequate permissions.
PVC_LINKDOWN10The link has gone down.
PVC_RMTERROR11No reponse from remote.
PVC_USRERROR12User interface error detected.
PVC_INTERROR13Internal error.
PVC_NOATTACH14Not attached yet.
PVC_WAIT15Wait code, not to user.

State

This message primitive is valid in the PVC attached phase.

Response

When an NS user issues a PVC Detach, the NS user expects a PVC Detach message primitive from the NS provider in response.

Equivalence

The PVC Detach message primitive is equivalent to the N_DISCON_REQ of the NPI.


5 NLI Input-Output Controls


5.1 Input-Output Control Data Structures


5.2 Input-Output Control Commands

N_snident- Configure a newly linked driver. Also N_linkent on Sun.
N_snmode-
N_snconfig- Configure wlcfg database for a subnetwork. Also N_linkconfig on Sun.
N_snread- Also N_linkread on Sun.
N_getstats- read X.25 global (multiplexer) statistics.
N_zerostats- reset X.25 global (multiplexer) statistics.
N_putpvcmap- change per VC packet and window sizes.
N_getpvcmap- get default packet and window sizes.
N_getVCstatus- get per VC state and statistics.
N_getVCstats- get per VC statistics. Sun only.
N_getnliversion-
N_getoneVCstats- get status and statisics for VC associated with the current stream. Sun only.
N_traceon- start packet level tracing.
N_traceoff- stop packet level tracing.
N_nuimsg-
N_nuiput- store a set of NUI mappings.
N_nuidel- delete specific NUI mapping.
N_nuiget- read specific NUI mapping.
N_nuimget- read all NUI mappings.
N_nuireset- delete all NUI mappings.
N_zeroVCstats- reset per VC statistics.
N_putx32map-
N_getx32map-
N_getSNIDstats- retrieve per subnetwork statistics. Also N_getlinkstats on Sun.
N_zeroSNIDstats- reset per subnetwork statistics.
N_setQOSDATPRI-
N_resetQOSDATPRI-
N_X25_ADD_ROUTE- add a new route or update an existing route. Sun only.
N_X25_FLUSH_ROUTE- clear all entries from the routing table. Sun only.
N_X25_GET_ROUTE- obtain routing information for a specific address. Sun only.
N_GET_NEXT_ROUTE- obtain routing information for next route in the routing table. Sun only.
N_RM_ROUTE- remove a specific route. Sun only.

5.2.1 N_snident

The N_snident input-output control identifies the subnetwork. This is performed by indicating the lower multiplex identifier returned from the I_LINK STREAMS operation and assigning a subnetwork identifier and a dl_sap and dl_max_conind to bind.

Format

The argument to the N_snident input-output control is a pointer to a xll_reg structure, formatted as follows:

struct xll_reg {
    uint32_t snid;
    uint32_t lmuxid;
    uint16_t dl_sap;
    uint16_t dl_max_conind;
};

Parameters

The xll_reg structure contains the following members:

snid

Specifies the subnetwork identifier to assign to the data link.

lmuxid

Identifies the data link as a linked Stream beneath the lower multiplex.

dl_sap

Specifies the DLSAP to bind the Stream.

dl_max_conind

Specifies the maximum number of connection indications to bind to the Stream.


5.2.2 N_snmode

The N_snmode input-output control adjusts only the subscription mode bits. When rd_wr is set to read, the subscription mode bits (see the SUB_MODES member in the wlcfg structure) are read; when set to write, the mode bits are written.

Format

The argument to the N_snmode input-output control is a pointer to a snoptformat structure, formatted as follows:

struct snoptformat {
    uint32_t U_SN_ID;
    uint16_t newSUB_MODES;
    uint8_t rd_wr;
};

Parameters

The snoptformat structure contains the following members:

U_SN_ID

Specifies the subnetwork identifier of the data link whose modes are to be read or written.

newSUB_MODES

Contains the read or written subnetwork modes. This can contain a bitmask of zero or more of the following bits:

0SUB_EXTENDEDSubscribe extended facilities.
1BAR_EXTENDEDBar extended facilities.
2SUB_FSELECTSubscribe fast select.
3BAR_FSELECTBar fast select.
4SUB_FSRRESPSubscribe fast select with restriction on response.
5SUB_REVCHARGESubscribe reverse charging.
6SUB_LOC_CHG_PREVSubscribe local charge prevention.
7BAR_INCALLBar incoming calls.
8BAR_OUTCALLBar ougoing calls.
9SUB_TOA_NPI_FMTSubscribe TOA/NPI address extensions.
10BAR_TOA_NPI_FMTBar TOA/NPI address extensions.
11SUB_NUI_OVERRIDESubscribe NUI override.
12BAR_CALL_X32_REGBar calls while X.32 registration in progress.
rd_wr

Specifies whether to read or write the subnetwork modes.


5.2.3 N_snconfig

The N_snconfig input-output control is used to configure a data link connected to a subnetwork, but subnetwork identifier.

Format

The argument to the N_snconfig input-output control is a pointer to a wlcfg structure, formatted as follows:

struct wlcfg {
    uint32_t U_SN_ID;
    uint8_t NET_MODE;
    uint8_t X25_VSN;
    uint8_t L3PLPMODE;
    uint16_t LPC;
    uint16_t HPC;
    uint16_t LIC;
    uint16_t HIC;
    uint16_t HTC;
    uint16_t LOC;
    uint16_t HOC;
    uint16_t NPCchannels;
    uint16_t NICchannels;
    uint16_t NTCchannels;
    uint16_t NOCchannels;
    uint16_t Nochnls;
    uint8_t THISGFI;
    uint8_t LOCMAXPKTSIZE;
    uint8_t REMMAXPKTSIZE;
    uint8_t LOCDEFPKTSIZE;
    uint8_t REMDEFPKTSIZE;
    uint8_t LOCMAXWSIZE;
    uint8_t REMMAXWSIZE;
    uint8_t LOCDEFWSIZE;
    uint8_t REMDEFWSIZE;
    uint16_t MAXNSDULEN;
    int16_t ACKDELAY;
    int16_t T20value;
    int16_t T21value;
    int16_t T22value;
    int16_t T23value;
    int16_t Tvalue;
    int16_t T25value;
    int16_t T26value;
    int16_t T28value;
    int16_t idlevalue;
    int16_t connectvalue;
    uint8_t R20value;
    uint8_t R22value;
    uint8_t R23value;
    uint8_t R28value;
    uint16_t localdelay;
    uint16_t accessdelay;
    uint8_t locmaxthclass;
    uint8_t remmaxthclass;
    uint8_t locdefthclass;
    uint8_t remdefthclass;
    uint8_t locminthclass;
    uint8_t remminthclass;
    uint8_t CUG_CONTROL;
    uint16_t SUB_MODES;
    struct {
        uint16_t SNMODES;
        uint8_t intl_addr_recogn;
        uint8_t intl_prioritised;
        uint8_t dnic1;
        uint8_t dnic2;
        uint8_t prty_encode_control;
        uint8_t prty_pkt_forced_value;
        uint8_t src_addr_control;
        uint8_t dbit_control;
        uint8_t thclass_neg_to_def;
        uint8_t thclass_type;
        uint8_t thclass_wmap[16];
        uint8_t thclass_pmap[16];
    } psdn_local;
    struct lsapformat local_address;
};

Parameters

The wlcfg structure contains the following members:

U_SN_ID
NET_MODE
X25_VSN
L3PLPMODE
LPC
HPC
LIC
HIC
HTC
LOC
HOC
NPCchannels
NICchannels
NTCchannels
NOCchannels
Nochnls
THISGFI
LOCMAXPKTSIZE
REMMAXPKTSIZE
LOCDEFPKTSIZE
REMDEFPKTSIZE
LOCMAXWSIZE
REMMAXWSIZE
LOCDEFWSIZE
REMDEFWSIZE
MAXNSDULEN
ACKDELAY
T20value
T21value
T22value
T23value
Tvalue
T25value
T26value
T28value
idlevalue
connectvalue
R20value
R22value
R23value
R28value
localdelay
accessdelay
locmaxthclass
remmaxthclass
locdefthclass
remdefthclass
locminthclass
remminthclass
CUG_CONTROL
SUB_MODES
psdn_local
SNMODES
intl_addr_recogn
intl_prioritised
dnic1
dnic2
prty_encode_control
prty_pkt_forced_value
src_addr_control
dbit_control
thclass_neg_to_def
thclass_type
thclass_wmap
thclass_pmap
local_address

5.2.4 N_snread

The N_snread input-output control is used to read the configuration information for a specified subnetwork identifier.

Format

The argument to the N_snread input-output control is a pointer to a wlcfg structure, see N_snconfig.

Parameters

See N_snconfig.


5.2.5 N_getstats

The N_getstats input-output control is used to collect the global statistics.

Format

The argument to the N_getstats input-output control is a pointer to a buffer aread containing 101 32-bit unsigned integer values.

Parameters

The buffer area contains 101 32-bit unsigned integer values as follows:

0cll_in_gCalls received and indicated.
1cll_out_gCalls sent.
2caa_in_gCalls established outgoing.
3caa_out_gCalls established incoming.
4ed_in_gInterrupts received.
5ed_out_gInterrupts sent.
6rnr_in_gReceiver not ready received.
7rnr_out_gReceiver not ready sent.
8rr_in_gReceiver ready received.
9rr_out_gReceiver ready sent.
10rst_in_gResets received.
11rst_out_gResets sent.
12rsc_in_gReset confirms received.
13rsc_out_gReset confirms sent.
14clr_in_gClears received.
15clr_out_gClears sent.
16clc_in_gClear confirms received.
17clc_out_gClear confirms sent.
18cll_coll_gCall collision count, not rejected.
19cll_uabort_gCalls aborted by user before sent.
20rjc_buflow_gCalls rejected no buffers before sent.
21rjc_coll_gCalls rejected collision DCE mode.
22rjc_failNRS_gCalls rejected negative NRS response.
23rjc_lstate_gCalls rejected link disconnecting.
24rjc_nochnl_gCalls rejected no local channels left.
25rjc_nouser_gCalls rejected no user on NSAP.
26rjc_remote_gCalls rejected by remote responder.
27rjc_u_gCalls rejected by NS user.
28dg_in_gDiagnostic packets received.
29dg_out_gDiagnostic packets sent.
30p4_ferr_gFormat errors in P4.
31rem_perr_gRemote protocol errors.
32res_ferr_gRestart format errors.
33res_in_gRestarts received (including DTE/DXE).
34res_out_gRestarts sent (including DTE/DXE).
35vcs_labort_gCircuits aborted by link event.
36r23exp_gCircuits hung by R23 expiry.
37l2conin_gLink level connection established.
38l2conok_gLLC connections accepted.
39l2conrej_gLLC connections rejected.
40l2refusal_gLLC connect requests refused.
41l2lzap_gOperator requests to kill link.
42l2r20exp_gR20 retransmission expiry.
43l2dxeexp_gDXE connect expiry.
44l2dxebuf_gDXE resolve abort, no buffers.
45l2noconfig_gNo configuration base.
46xiffnerror_gUpper interface bad M_PROTO type.
47xintdisc_gInternal disconnecte events.
48xifaborts_gUpper interface abort_vc called.
49PVCusergone_gCount of non-user interactions.
50max_opens_gHighest number of simultaneous opens.
51vcs_est_gVirtual circuits established since reset.
52bytes_in_gBytes received.
53bytes_out_gBytes sent.
54dt_in_gData packets received.
55dt_out_gData packets sent.
56res_conf_in_gRestart confirms received.
57res_conf_out_gRestart confirms sent.
58reg_in_gRegistration requests received.
59reg_out_gRegistration requests sent.
60reg_conf_in_gRegistration confirms received.
61reg_conf_out_gRegistration confirms sent.
62l2r28exp_gR28 retransmission expiries.
63Cantlzap_gOperator link reset refused.
64L2badcc_g-
65L2baddcnf_g-
66L3T25timeouts_g-
67L3badAE_g-
68L3badT20_g-
69L3badT24_g-
70L3badT25_g-
71L3badT28_g-
72L3badevent_g-
73L3badgfi_g-
74L3badlstate_g-
75L3badltock2_g-
76L3badrandom_g-
77L3badxtock0_g-
78L3clrbadstate_g-
79L3conlt0_g-
80L3deqfailed_g-
81L3indnodata_g-
82L3matrixcall_g-
83L3nodb_g-
84L3qoscheck_g-
85L3outbad_g-
86L3shortframe_g-
87L3tabfault_g-
88L3usererror_g-
89L3usergone_g-
90LNeednotneeded_g-
91NSUbadref_g-
92NSUdtnull_g-
93NSUednull_g-
94NSUrefrange_g-
95NeednotNeeded_g-
96NoNRSrequest_t-
97UDRbad_g-
98Ubadint_g-
99Unoint_g-
100L3baddiag_g-

5.2.6 N_zerostats

The N_zerostats input-output control is used to zero the global statistics. The same statistics buffer as is provided for N_getstats is provided so that the statistics immediately before the reset can be collected.

Format

The format of the buffer area of the N_zerostats input-output control is identical to that of N_getstats.

Parameters

The parameters of the buffer contain the statistics that were collected immediately before resetting the statistics to zero.


5.2.7 N_putpvcmap

Format

struct pvcmapf {
    int first_ent;
    int num_ent;
    struct pvcconf entries[0];
};
struct pvcconf {
    uint32_t sn_id;
    uint16_t lci;
    uint8_t locpacket;
    uint8_t rempacket;
    uint8_t locwsize;
    uint8_t remwsize;
};

Parameters

first_ent
num_ent
entries
sn_id
lci
locpacket
rempacket
locwsize
remwsize

5.2.8 N_getpvcmap


5.2.9 N_getVCstatus

Format

struct vcstatusf {
    int first_ent;
    int num_ent;
    struct vcinfo vc;
};
struct vcinfo {
    struct xaddrf rem_addr;
    struct xaddrf loc_addr;
    uint32_t xu_ident;
    uint32_t process_id;
    uint16_t lci;
    uint8_t xstate;
    uint8_t xtag;
    uint8_t ampvc;
    uint8_t call_direction;
    uint8_t vctype;
    uint32_t perVC_stats[27];
};

Parameters

first_ent
num_ent
vc
rem_addr
loc_addr
xu_ident
process_id
lci
xstate
xtag
ampvc
call_direction
vctype
perVC_stats
0cll_in_vCalls received and indicated.
1cll_out_vCalls sent.
2caa_in_vCalls established outgoing.
3caa_out_vCalls established incoming.
4dt_in_vData packets received.
5dt_out_vData packets sent.
6ed_in_vInterrupts received.
7ed_out_vInterrupts sent.
8rnr_in_vReceiver not ready received.
9rnr_out_vReceiver not ready sent.
10rr_in_vReceiver ready received.
11rr_out_vReceiver ready sent.
12rst_in_vResets received.
13rst_out_vResets sent.
14rsc_in_vRestart confirms received.
15rsc_out_vRestart confirms sent.
16clr_in_vClears received.
17clr_out_vClears sent.
18clc_in_vClear confirms received.
19clc_out_vClear confirms sent.
20octets_in_vOctets received.
21octets_out_vOctets sent.
22rst_timeouts_vReset timeouts.
23ed_timeouts_vInterrupt timeouts.
24prov_rst_in_vProvider initiated resets.
25rem_rst_in_vRemote initiated resets.

5.2.10 N_getnliversion

Format

struct nliformat {
    unsigned char version;
};

Parameters

version

5.2.11 N_traceon


5.2.12 N_traceoff


5.2.13 NUI_MSG Input-Output Controls


5.2.13.1 N_nuimsg


5.2.13.2 N_nuiput

Format

struct nui_put {
    char prim_class;
    char op;
    struct nuiformat nuid;
    struct facformat nuifacility;
};

Parameters

prim_class

Always NUI_MSG.

op

Always NUI_PUT.

nuid
nuifacility

5.2.13.3 N_nuidel

Format

struct nui_del {
    char prim_class;
    char op;
    struct nuiformat nuid;
};

Parameters

prim_class

Always NUI_MSG.

op

Always NUI_DEL.

nuid

5.2.13.4 N_nuiget

Format

struct nui_get {
    char prim_class;
    char op;
    struct nuiformat nuid;
    struct facformat nuifacility;
};

Parameters

prim_class

Always NUI_MSG.

op

Always NUI_GET.

nuid
nuifacility

5.2.13.5 N_nuimget

Format

struct nui_mget {
    char prim_class;
    char op;
    unsigned int first_ent;
    unsigned int last_ent;
    unsigned int num_ent;
    union {
        char buf[0];
        struct nui_addr entries[0];
    };
};

Parameters

prim_class

Always NUI_MSG.

op

Always NUI_MGET.

first_ent
last_ent
num_ent
buf
entries

5.2.13.6 N_nuireset

Format

struct nui_reset {
    char prim_class;
    char op;
};

Parameters

prim_class

Always NUI_MSG.

op

Always NUI_RESET.


5.2.14 N_zeroVCstats


5.2.15 N_putx32map


5.2.16 N_getx32map


5.2.17 N_getSNIDstats

Format

struct persnidstats {
    uint32_t snid;
    int32_t network_state;
    uint32_t mon_array[59];
};

Parameters

snid
network_state
mon_array
0cll_in_sCalls received.
1cll_out_sCalls sent.
2caa_in_sCalls established outgoing.
3caa_out_sCalls established incoming.
4dt_in_sData packets received.
5dt_out_sData packets sent.
6ed_in_sInterrupts received.
7ed_out_sInterrupts sent.
8rnr_in_sReceiver not ready received.
9rnr_out_sReceiver not ready sent.
10rr_in_sReceiver ready received.
11rr_out_sReceiver ready sent.
12prov_rst_in_sProvider initiated resets received.
13rem_rst_in_sRemote initiated resets received.
14rsc_in_sReset confirms received.
15rsc_out_sReset confirms sent.
16prov_clr_in_sProvider initiated clears received.
17clc_in_sClear confirms received.
18clc_out_sClear confirms sent.
19perr_in_sPackets with protocol errors received.
20out_vcs_sOutgoing circuits.
21in_vcs_sIncoming circuits.
22twoway_vcs_sTwo-way circuits.
23res_in_sRestarts received.
24res_out_sRestarts sent.
25res_timeouts_sRestart timeouts.
26cll_timeouts_sCall timeouts.
27rst_timeouts_sReset timeouts.
28clr_timeouts_sClear timeouts.
29ed_timeouts_sInterrupt timeouts.
30retry_exceed_sRetry count exceeded.
31clear_exceed_sClear count exceeded.
32octets_in_sOctets received.
33octets_out_sOctets sent.
34rec_in_sRestart confirms received.
35rec_out_sRestart confirms sent.
36rst_in_sReset confirms received.
37rst_out_sReset confirms sent.
38dg_in_sDiagnostic packets received.
39dg_out_sDiagnostic packets sent.
40res_in_conn_sRestarts in connected state.
41clr_in_sClears received.
42clr_out_sClears sent.
43pkts_in_sPackets received.
44pkts_out_sPackets sent.
45vcs_est_sSVCs established.
46max_svcs_sMaximum number of SVCs opened.
47svcs_sSVCs currently open.
48pvcs_sPVCs currently attached.
49max_pvcs_sMaximum number of PVCs ever attached.
50rjc_coll_sCall rejects overload.
51rjc_failNRS_sCall rejects failed no resource.
52rjc_nouser_sCall rejects failed no user.
53rjc_buflow_sCall rejects buffers low.
54reg_in_sRegistration requests received.
55reg_out_sRegistration requests sent.
56reg_conf_in_sRegistration confirms received.
57reg_conf_out_sRegistration confirms sent.

5.2.18 N_zeroSNIDstats


5.2.19 N_setQOSDATPRI

Format

struct qosdatpri {
    int32_t band;
    uint32_t tx_window;
};

Parameters

band
tx_window;

5.2.20 N_resetQOSDATPRI


6 NLI Management Information Base

The OPENSS7-X25-MIB provides the following tables:

x25PLEConfigTable:X.25 Packet Layer Entity (PLE) Configuration Table
x25PLEProfileTable:X.25 Packet Layer Entity (PLE) Profile Table
x25PLEStateTable:X.25 Packet Layer Entity (PLE) State Table
x25PLEStatsTable:X.25 Packet Layer Entity (PLE) Statistics Table
x25VCConfigTable:X.25 Virtual Circuit (VC) Configuration Table
x25VCProfileTable:X.25 Virtual Circuit (VC) Profile Table
x25VCStatsTable:X.25 Virtual Circuit (VC) Statistics Table
x25PVCConfigTable:X.25 Permanent Virtual Circuit (PVC) Configuration Table
x25SVCConfigTable:X.25 Switched Virtual Circuit (SVC) Configuration Table

6.1 X.25 Packet Layer Entity (PLE) Configuration Table

The X.25 Packet Layer Entity (PLE) Configuration Table, x25PLEConfigTable, is a table that provides specific configuration information for various X.25 Packet Layer Entities.

Provides a table of X.25 Packet Layer Protocol (PLP) Entities. Each X.25 Packet Layer Entity corresponds to an X.25 DTE or DCE over which permanent virtual circuits exist or virtual calls can be placed. ITU-T Rec. X.283 | ISO/IEC 10733. Each entry corresponds to an instance of an x25PLE managed object, which represents a DTE, DCE or DXE X.25 packet layer entity, from which permanent virtual circuits are formed or virtual calls are established. ITU-T Rec. X.283 | ISO/IEC 10733.

x25PLEConfigIndex

Provides and index for the PLE configuration entry.

x25PLEConfigProtocolVersionSupported

The protocol versions of ISO8208 available on the PLE interface.

x25PLEConfigLocalDTEAddress

The full DTE address of this PLE expressed as an X.121, X.31, etc. address.

x25PLEConfigInterfaceMode

The DCE/DTE mode in which the interface is currently operating.

dTE(0)- Data Terminal Equiment
dCE(1)- Data Circuit-terminating Equipment
dXE(2)- Data eXchange Equipment (DTE/DCE)
x25PLEConfigDefaultThroughputClass

The default throughput class value currently agreed with the DCE. This may be the normal default, or may have been changed as a result of the use of the defaultThroughputClassAssignment facility.

x25PLEConfigFlowControlNegotiationPermitted

Indicates whether flow control parameter negotiation is permitted. When this has the value ‘true(1)’, the use of flow control parameter negotiation (by specifying values for the window and packet size in call request and accept packets) is permitted. When it has the value ‘false(2)’, no such values shall be specified in call request and accept packets, and any values specified in a Profile or via an internal interface shall be ignored.

x25PLEConfigCallDeflectionSubscription

Indicates whether call deflection has been subscribed to. When this has value ‘true(1)’, call deflection has been subscribed to. Otherwise it has the value ‘false(2)’.

x25PLEConfigMaxActiveCalls

The maximum number of active circuits permitted on this PLE. When the NULL value (zero (0)) is specified, the maximum number of active circuits shall be limited only by the resources available to the entity.

x25PLEConfigRestartTime

Value for Timer T20 (Restart Request Response Timer) in centiseconds. Note that the default timer is ultimately dependent upon the underlying data link provider type.

x25PLEConfigDefaultPacketSizeIncoming

The default value of the packet size parameter for this DTE. A value of NULL (zero (0)) indicates the ISO/IEC 8208 or ITU-T Rec. X.25 default value of ‘128’. Any other value indicates the value agreed by the nonstandard default packet size facility.

x25PLEConfigDefaultPacketSizeOutgoing

The default value of the packet size parameter for this DTE. A value of NULL (zero (0)) indicates the ISO/IEC 8208 or ITU-T Rec. X.25 default value of ‘128’. Any other value indicates the value agreed by the nonstandard default packet size facility.

x25PLEConfigDefaultWindowSizeIncoming

The default value of the window size parameter for this DTE. A value of NULL (zero (0)) indicates the ISO/IEC 8208 or ITU-T Rec X.25 default value of ‘2’. Any other value indicates the value agreed by the nonstandard default window sizes facility.

x25PLEConfigDefaultWindowSizeOutgoing

The default value of the window size parameter for this DTE. A value of NULL (zero (0)) indicates the ISO/IEC 8208 or ITU-T Rec X.25 default value of ‘2’. Any other value indicates the value agreed by the nonstandard default window sizes facility.

x25PLEConfigMinimumRecallTimer

Minimum time in centiseconds before recall permitted. This timer determines the minimum interval (in centiseconds) which shall elapse following an unsuccessful first call attempt before a subsequent call attempt is permitted.

x25PLEConfigRestartCount

Value for Count R20 (Restart Request Retransmission Count).

x25PLEConfigSN-ServiceProvider

Distinguished name of the subnetwork (SN) service provider Managed Object. This attribute identifies the subnetwork entity to be used to support the linkage, when enabled. The subnetwork service provider may be in the data link layer, or it may be in the network layer (for example when operating ISO 8473 over the ISO 8208 SNDCF).10

x25PLEConfigSN-SA-P

Distinguished name of the service provider SA-P Managed Object (if present). This is obtained via an internal interface when the linkage is enabled. The sN-SA-P may be a relationship to a SA-P Managed Object in the data link layer, or it may be a relationship to another Managed Object within the network layer which is not a SA-P Managed Object. For example, when operating ISO 8473 over the ISO 8208 SNDCF, it is a relationship to the same x25PLE Managed Object which is pointed to by the sN-ServiceProvider Attribute.11

x25PLEConfigLogicalChannelAssignmentsPVC

Represents the logical channel assignments of this PLE, expressed as a four-tuple where the values represent the set (with maximum permitted cardinality (LIC - 1), minimum required cardinality of zero) of PVC channels (with a maximum value (LIC - 1), and minimum value 1) assigned, the incoming channel range, the two-way channel range, the outgoing channel range, respectively.

The presence of each of the ranges shall be optional. Absence of a particular range shall signify that there are no channels of that type assigned. Within each range, the low value shall be less than or equal to the high value, and there shall be no value in any set or range which is greater than or equal to a value in a subsequent range when ordered as above.

This attribute is subject to the rules for logical assignments described in ISO/IEC 8208 clause 3.7. it is understood that the Highest Permanent Channel (HPC) is defined by the Lowest Incoming Channel (LIC) value minus one.

The OCTET STRING is encoded as two octets, most significant octet followed by least significant octet, where each pair of octets represents another channel number from ‘1..4095’ (but less than LIC), the logical channel number to which a Permanent Virtual Circuit (PVC) has been assigned.12

x25PLEConfigLogicalChannelAssignmentsLIC

The lowest incoming logical channel in the incoming logical channel range. When set to zero (0), or the same value as the highest incoming logical channel, it indicates that there is no incoming logical channel range and the highest incoming logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.13

x25PLEConfigLogicalChannelAssignmentsHIC

The highest incoming logical channel in the incoming logical channel range. When set to zero (0), or the same value as the lowest incoming logical channel, it indicates that there is no incoming logical channel range and the lowest incoming logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.14

x25PLEConfigLogicalChannelAssignmentsL2W

The lowest two-way logical channel in the two-way logical channel range. When set to zero (0), or to the same value as the highest two-way logical channel, it indicates that there is no two-way logical channel range and the highest two-way logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.15

x25PLEConfigLogicalChannelAssignmentsH2W

The highest two-way logical channel in the two-way logical channel range. When set to zero (0), or to the same value as the lowest two-way logical channel, it indicates that there is no two-way logical channel range and the lowest two-way logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.16

x25PLEConfigLogicalChannelAssignmentsLOG

The lowest outgoing logical channel in the outgoing logical channel range. When set to zero (0), or to the same value as the highest outgoing logical channel, it indicates that there is no outgoing channel range and the highest outgoing logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.17

x25PLEConfigLogicalChannelAssignmentsHOG

The highest outgoing logical channel in the outgoing logical channel range. When set to zero (0), or to the same value as the lowest outgoing logical channel, it indicates that there is no outgoing logical channel range and the lowest outgoing logical channel is otherwise ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.18

x25PLEConfigPacketSequencing

The modulo of the packet sequence number space. Expressed as an integer. ISO/IEC 8208 only requires support for at least one of the two values ‘8’ and ‘128’, but it is possible that some future revision may extend the range.19 A system is only required to support the setting of values which are also required by the protocol standard. A system shall return an error when an attempt is made to set the value to a value which is not supported by that system.20

8-Modulo 83 bits
128-Modulo 1287 bits
32768-Modulo 3276815 bits
x25PLEConfigPLEClientMOName

The Distinguished name of the client Managed Object. Note that this will either be a Transport Layer Managed Object or a CLNS Managed Object.21

x25PLEConfigRegistrationRequestTime

Value for Timer T28 (Registration Request Timer) in centiseconds.22

x25PLEConfigRegistrationRequestCount

Value for Count R28 (Registration Request Count).23

x25PLEConfigRegistrationPermitted

When ‘true(1)’, the use of on-line facility registration is permitted. Otherwise, the value is ‘false(2)’.24


6.2 X.25 Packet Layer Entity (PLE) Profile Table

The Packet Layer Entity (PLE) Profile Table, x25PLEProfileTable, is a table that provides a common set of X.25 packet layer entity (PLE) configuration parameters organized into a referencable profile.

This table provides profiles for the x25PLE. These profiles are not created nor deleted by management stations; however, their values may be altered. Each entry in the table consists of a separate profile. The managed element may choose to use profile values when creating instances of x25PLEs (entries in the x25PLEConfig table.25

Each entry in the table provides a separate profile identified by the x25PLEProfileName which consists of a DisplayString used to identify the profile. The agent or implementation may used specific profiles to create instances of x25PLEs. Management stations may not create nor delete entries in this table, however, the values associated with a given profile may be altered.26

x25PLEProfileName
x25PLEProfileLocalDTEAddress
x25PLEProfileInterfaceMode

The DCE/DTE mode in which the interface is currently operating.27

dTE(0)-Data Terminating Equipment (DTE)
dCE(1)-Data Circuit-terminating Equipment (DCE)
dXE(2)-Data eXchange Equipment (DTE/DCE)
x25PLEProfileDefaultThroughputClass

The default throughput class value currently agreed with the DCE. This may be the normal default, or may have been changed as a result of the use of the defaultThroughputClassAssignment facility.

x25PLEProfileFlowControlNegotiationPermitted

Indicates whether flow control parameter negotiation is permitted. When this has the value ‘true(1)’, the use of flow control parameter negotiation (by specifying values for the window and packet size in call request and accept packets) is permitted. When it has the value ‘false(2)’, no such values shall be specified in call request and accept packets, and any values specified in a Profile or via an internal interface shall be ignored.28

x25PLEProfileCallDeflectionSubscription

Indicates whether call deflection has been subscribed to. When this has value ‘true(1)’, call deflection has been subscribed to.29

x25PLEProfileMaxActiveCircuits

The maximum number of active circuits permitted on this PLE. When the NULL value (zero (0)) is specified, the maximum number of active circuits shall be limited only by the resources available to the entity.30

x25PLEProfileRestartTime

Value for Timer T20 (Restart Request Response Timer) in centiseconds. Note that the default timer is ultimately dependent upon the underlying data link provider type.31

x25PLEProfileDefaulPacketSizeIncoming

The default value of the packet size parameter for this DTE. A value of NULL (zero (0)) indicates the ISO 8208 default value of 128. Any other value indicates the value agreed by the nonstandard default packet size facility.32

x25PLEProfileDefaulPacketSizeOutgoing

The default value of the packet size parameter for this DTE. A value of NULL (zero (0)) indicates the ISO/IEC 8208 or ITU-T Rec. X.25 default value of 128. Any other value indicates the value agreed by the nonstandard default packet size facility.33

x25PLEProfileDefaultWindowSizeIncoming

The default value of the window size parameter for this DTE. A value of NULL (zero (0)) indicates the ISO/IEC 8208 or ITU-T Rec X.25 default value of 2. Any other value indicates the value agreed by the nonstandard default window sizes facility.34

x25PLEProfileDefaultWindowSizeOutgoing

The default value of the window size parameter for this DTE. A value of NULL (zero (0)) indicates the ISO/IEC 8208 or ITU-T Rec X.25 default value of 2. Any other value indicates the value agreed by the nonstandard default window sizes facility.35

x25PLEProfileMinimumRecallTimer

Minimum time in centiseconds before recall permitted. This timer determines the minimum interval (in centiseconds) which shall elapse following an unsuccessful first call attempt before a subsequent call attempt is permitted.36

x25PLEProfileRestartCount

Value for Count R20 (Restart Request Retransmission Count).37

x25PLEProfileSN-ServiceProvider

Distinguished name of the subnetwork (SN) service provider Managed Object. This attribute identifies the subnetwork entity to be used to support the linkage, when enabled. The subnetwork service provider may be in the data link layer, or it may be in the network layer (for example when operating ISO 8473 over the ISO 8208 SNDCF).38

x25PLEProfileSN-SA-P

Distinguished name of the service provider SA-P Managed Object (if present). This is obtained via an internal interface when the linkage is enabled. The sN-SA-P may be a relationship to a SA-P Managed Object in the data link layer, or it may be a relationship to another Managed Object within the network layer which is not a SA-P Managed Object. For example, when operating ISO 8473 over the ISO 8208 SNDCF, it is a relationship to the same x25PLE Managed Object which is pointed to by the sN-ServiceProvider Attribute.39

x25PLEProfileLogicalChannelAssignementsPVC

Represents the logical channel assignments of this PLE, expressed as a four-tuple where the values represent the set (with maximum permitted cardinality (LIC - 1), minimum required cardinality of zero) of PVC channels (with a maximum value (LIC - 1), and minimum value 1) assigned, the incoming channel range, the two-way channel range, the outgoing channel range, respectively.

The presence of each of the ranges shall be optional. Absence of a particular range shall signify that there are no channels of that type assigned. Within each range, the low value shall be less than or equal to the high value, and there shall be no value in any set or range which is greater than or equal to a value in a subsequent range when ordered as above.

This attribute is subject to the rules for logical assignments described in ISO/IEC 8208 clause 3.7. it is understood that the Highest Permanent Channel (HPC) is defined by the Lowest Incoming Channel (LIC) value minus one.

The OCTET STRING is encoded as two octets, most significant octet followed by least significant octet, where each pair of octets represents another channel number from 1..4095 (but less than LIC), the logical channel number to which a Permanent Virtual Circuit (PVC) has been assigned.40

x25PLEProfileLogicalChannelAssignementsLIC

The lowest incoming logical channel in the incoming logical channel range. When set to zero (0), or the same value as the highest incoming logical channel, it indicates that there is no incoming logical channel range and the highest incoming logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.41

x25PLEProfileLogicalChannelAssignementsHIC

The highest incoming logical channel in the incoming logical channel range. When set to zero (0), or the same value as the lowest incoming logical channel, it indicates that there is no incoming logical channel range and the lowest incoming logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.42

x25PLEProfileLogicalChannelAssignementsL2W

The lowest two-way logical channel in the two-way logical channel range. When set to zero (0), or to the same value as the highest two-way logical channel, it indicates that there is no two-way logical channel range and the highest two-way logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.43

x25PLEProfileLogicalChannelAssignementsH2W

The highest two-way logical channel in the two-way logical channel range. When set to zero (0), or to the same value as the lowest two-way logical channel, it indicates that there is no two-way logical channel range and the lowest two-way logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.44

x25PLEProfileLogicalChannelAssignementsLOG

The lowest outgoing logical channel in the outgoing logical channel range. When set to zero (0), or to the same value as the highest outgoing logical channel, it indicates that there is no outgoing channel range and the highest outgoing logical channel is ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.45

x25PLEProfileLogicalChannelAssignementsHOG

The highest outgoing logical channel in the outgoing logical channel range. When set to zero (0), or to the same value as the lowest outgoing logical channel, it indicates that there is no outgoing logical channel range and the lowest outgoing logical channel is otherwise ignored.

This value is subject to the rules for logical channel assignments described in ISO/IEC 8208 clause 3.7.46

x25PLEProfilePacketSequencing

The module of the packet sequence number space. Expressed as an integer. ISO/IEC 8208 only requires support for at least one of the two values 8 and 128, but it is possible that some future revision may extend the range. A system is only required to support the setting of values which are also required by the protocol standard. A system shall return an error when an attempt is made to set the value to a value which is not supported by that system.47

x25PLEProfileRegistrationRequestTime

Value for Timer T28 (Registration Request Timer) in centiseconds.48

x25PLEProfileRegistrationRequestCount

Value for Count R28 (Registration Request Count).49

x25PLEProfileRegistrationPermitted

When ‘true(1)’, the use of online facility registration is permitted.50


6.3 X.25 Packet Layer Entity (PLE) State Table

The X.25 Packet Layer Entity (PLE) State Table, x25PLEStateTable, is a table that provides the current states for various X.25 packet layer entities.

The x25PLEStateTable provides state information for each x25PLE object which are represented by the rows in the table. Each row corresponds to an X.25 Packet Layer Entity.51

The x25PLEStateEntry provides an entry in the X.25 Packet Layer Entity state table which provides the state information for a single packet layer entity as indicated by the index into the table.52

x25PLEStateIndex

Provides an index for the PLE state table.

x25PLEStateAdministrativeState

Provides the administrative state of the PLE following the AdministrativeState textual convention of the OPENSS7-SMI-MIB module.53

x25PLEStateOperationalState

Provides the operational state of the PLE following the OperationalState textual convention of the OPENSS7-SMI-MIB module.54

x25PLEStateUsageState

Provides the usage status of the PLE following the UsageStatus textual convention of the OPENSS7-SMI-MIB module.55

x25PLEStateProceduralStatus

Provides the procedural status of the PLE following the ProceduralStatus textual convention of the OPENSS7-SMI-MIB module.56

x25PLEStateAlarmStatus

Provides the alarm status of the PLE following the AlarmStatus textual convention of the OPENSS7-SMI-MIB module.57


6.4 X.25 Packet Layer Entity (PLE) Statistics Table

The X.25 Packet Layer Entity (PLE) Statistics Table, x25PLEStatsTable, is a table that provides statistics for various X.25 packet layer entities.

The x25PLEStatsTable provides statistics and counts for each X25PLE object which are represented by the rows in the table. Each row corresponds to an X.25 Packet Layer Entity.58

An entry in the x25PLEStatsTable. Each row or entry provides statistics for one X.25 Packet Layer Entity. Rows cannot be created or deleted by management stations.59

x25PLEStatsIndex
x25PLEStatsOctetsSentCounter

This corresponds to the ISO/IEC 8208 Octets Sent attribute. Note that the DMI definition is in terms of user data octets.60

x25PLEStatsOctetsReceivedCounter

This corresponds to the ISO/IEC 8208 Octets Received attribute. Note that the DMI definition is in terms of user data octets.61

x25PLEStatsDataPacketsSent

Counter of the total number of data packets sent.62

x25PLEStatsDataPacketsReceived
x25PLEStatsCallAttempts

Counter of the total number of data packets received.63

x25PLEStatsCallsConnected

Counter of the total number of calls which have reached the open state.64

x25PLEStatsProviderInitiatedDisconnects

Counter for the provider initiated disconnect events which generate communications alarm notifications.65

x25PLEStatsCallTimeouts

Counter of the number of times timer T21 expiry is experienced by the PLE. 66

x25PLEStatsClearTimeouts

Counter of the number of times timer T23 expiry is experienced by the PLE. ISO/IEC 10733 : clearTimeouts.

x25PLEStatsRemotelyInitiatedResets

Counter associated with the remotely initiated reset event which generates a communications alarm notification.67

x25PLEStatsDataRetransmissionTimerExpires

Counter of the number of expires of timer T25. Returns zero if the option is not implemented.68

x25PLEStatsProviderInitiatedResets

Counter associated with the provider initiated reset event which generates a communication alarm notification.69

x25PLEStatsResetTimeouts

Counter of the number of timer T22 expires experienced by the PLE.70

x25PLEStatsRemotelyInitiatedRestarts

Counter of the number of remotely initiated restarts. This is the total number of remotely initiated (including provider initiated) restarts experienced by the PLE, excluding the restart associated with bringing up the PLE interface. 71

x25PLEStatsRestartCountsExceeded

Counter associated with the restart count exceeded event which generate a communication alarm notification.72

x25PLEStatsProtocolErrorsDetectedLocally

Counter associated with the protocol error detected locally event which generates a communications alarm notification.73

x25PLEStatsProtocolErrorsAccusedOf

Counter associated wtih the accused of protocol error event which generates communications alarm notification.74

x25PLEStatsCallEstablishmentRetryCountsExceeded

Counter associated with the call establishment retry count exceeded event which generates a communications alarm notification.75

x25PLEStatsClearCountsExceeded

Counter associated with the clear count exceeded event which generates a communications alarm notification.76


6.5 X.25 Virtual Circuit (VC) Configuration Table

The X.25 Virtual Circuit (VC) Configuration Table, x25VCConfigTable, is a table that provides specific configuration information for various virtual circuits (VC) belonging to the various X.25 packet layer entities (PLE).

x25VCConfigId

ITU-T Rec. X.283 | ISO/IEC 10742.

x25VCConfigChannel

ITU-T Rec. X.283 | ISO/IEC 10742.

x25VCConfigPacketSizeIncoming

The incoming packet size for this VC. In the case of a profile entry, it is the proposed value of the incoming packet size to be used when establishing the virtual call, expressed in octets. The value NULL (or zero (0)) indicates that the default incoming packet size as indicated by the x25PLEConfigDefaultPacketSizeIncoming attribute of the containing x25PLE entry), is to be used. In the case of a non-profile entry, it is the actual packet size in use for the VC. ITU-T Rec. X.283 | ISO/IEC 10742.

x25VCConfigPacketSizeOutgoing

The outgoing packet size for this VC. In the case of a profile entry, it is the proposed value of the outgoing packet size to be used when establishing the virtual call, expressed in octets. The value NULL (or zero (0)) indicates that the default outgoing packet size as indicated by the x25PLEConfigDefaultPacketSizeOutgoing attribute of the containing x25PLE etnry), is to be used. Int he case of a non-profile entry, it is the actual packet size in used for the VC. ITU-T Rec. X.283 | ISO/IEC 10742.

x25VCConfigWindowSizeIncoming

The actual incoming window size in use for this VC. ITU-T Rec. X.283 | ISO/IEC 10742.

x25VCConfigWindowSizeOutgoing

The actual outgoing window size in use for this VC. ITU-T Rec. X.283 | ISO/IEC 10742.

x25VConfigThroughputClassIncoming

The incoming throughput class in use or to be used. For a profile, this is the throughput class to be proposed. For a non-profile it is the actual throughput class in use. For Virtual Calls this is the result of negotiation. ITU-T Rec. X.283 | ISO/IEC 10742.

x25VConfigThroughputClassOutgoing

The outgoing throughput class in use or to be used. For a profile, this is the throughput class to be proposed. For a non-profile it is the actual throughput class in use. For Virtual Calls this is the result of negotiation. ITU-T Rec. X.283 | ISO/IEC 10742.


6.6 X.25 Virtual Circuit (VC) Profile Table

The X.25 Virtual Circuit (VC) Profile Table x25VCProfileTable, is a table that provides a common set of virtual circuit (VC) configuration parameters organized into a referencable profile.

This managed object exists in order to permit the values of various parameters of a virtual call to be specified in advance by management. When a virtual call is to be established, the values of all the parameters to be used can be identified by specifying an instance of this Managed Object. However it is permitted for values specified by other means (for example, across and internal user interface) to override the values supplied in the profile. There may be multiple entries in this table. ISO/IEC 10733 : virtualCall.

x25VCProfileId

ISO/IEC 10733.

x25VCProfileProposedPacketSizeIncoming

The proposed value of the packet size parameter to be used when establishing the virtual call, expressed in octets. The value of NULL (zero (0)) indicates that the default packet size (as indicated by the defaultPacketSize attribute of the containing X.25 PLE Managed Object), is to be used. ISO/IEC 10733.

x25VCProfileProposedPacketSizeOutgoing

The proposed value of the packet size parameter to be used when establishing the virtual call, expressed in octets. The value of NULL (zero (0)) indicates that the default packet size (as indicated by the defaultPacketSize attribute of the containing X.25 PLE Managed Object), is to be used. ISO/IEC 10733.

x25VCProfileProposedWindowSizeIncoming

The proposed value of the window size parameter to be used when establishing the virtual call. The value of NULL (zero (0)) indicates that the default window size (as indicated by the defaultWindowSize attribute of the containing X.25 PLE Managed Object), is to be used. ISO/IEC 10733.

x25VCProfileProposedWindowSizeOutgoing

The proposed value of the window size parameter to be used when establishing the virtual call. The value of NULL (zero (0)) indicates that the default window size (as indicated by the defaultWindowSize attribute of the containing X.25 PLE Managed Object), is to be used. ISO/IEC 10733.

x25VCProfileAcceptReverseCharging

When ‘false(2)’, an incoming call requesting reverse charging shall not be accepted. ISO/IEC 10733.

x25VCProfileProposeReverseCharging

When ‘true(1)’, an outgoing call shall be initiated requesting reverse charging. ISO/IEC 10733.

x25VCProfileFastSelect

Type of fast select to be used for the call. This specifies that one of ’fast select’, ’fast select with restricted response’, or no fast select facility is to be used for the call. Includes a value ’not specified’ which indicates that no preference is expressed. ISO/IEC 10733.

notSpecified(0)Unspecified or unknown.
fastSelect(1)Fast Select with unrestricted response.
fastSelectWithRestrictedResponse(2)Fast Select with restricted response.
noFastSelect(3)No fast select.
x25VCProfileCallTime

Value for Timer T21 (Call Request Response Timer) in centiseconds. ISO/IEC 10733.

x25VCProfileResetTime

The value for Timer T22 (Reset Request Response Timer) in centiseconds. ISO/IEC 10733.

x25VCProfileClearTime

Value for Timer T23 (Clear Request Response Timer) in centiseconds. ISO/IEC 10733.

x25VCProfileInterruptTime

Value for Timer T26 (Interrupt Response Timer) in centiseconds. ISO/IEC 10733.

x25VCProfileResetCount

Value for Count R22 (Reset Request Retransmission Count). ISO/IEC 10733.

x25VCProfileClearCount

Value for Count R23 (Clear Request Retransmission Count). ISO/IEC 10733.

x25VCProfileWindowTime

Value for Timer 24 (Window Status Transmission Timer) in centiseconds.

Valid when implemented and using the optional window rotation recovery procedures at a receiving DTE as described in Clause 11.2.2 of ISO/IEC 8208 (2nd Edition). ISO/IEC 10733, ISO/IEC 8208 clause 11.2.2.

x25VCProfileDataRetransmissionTime

Default for Timer T25 (Window Rotation Timer) in centiseconds.

Valid when implemented and using the operation transmitting window rotation recovery procedures at a transmitting DTE as described in Clause 11.2.1 of ISO/IEC 8208 (2nd Edition). ISO/IEC 10733.

x25VCProfileDataRetransmissionCount

Value for Count R25 (Data Packet Retransmission Count).

Valid when implemented and using the operation transmitting window rotation recovery procedures at a transmitting DTE as described in Clause 11.2.1 of ISO/IEC 8208 (2nd Edition). ISO/IEC 10733.

x25VCProfileRejectTime

Value for Timer T27 (Reject Response Timer) in centiseconds.

Valid when the optional packet retransmission procedures are implemented and used. ISO/IEC 10733.

x25VCProfileRejectCount

Value for Count R27 (Reject Retransmission Count).

Valid when the optional packet retransmission procedures are implemented and used. ISO/IEC 10733.


6.7 X.25 Virtual Circuit (VC) Statistics Table

The X.25 Virtual Circuit (VC) Statistics Table, x25VCStatsTable, is a table that provides statistics for various virtual circuits (VC) belonging to the various X.25 packet layer entities (PLE).

x25VCStatsIndex

ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsChannel

ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsOctetsSentCounter

ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsOctetsReceivedCounter

ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsDataPacketsSent

Counter of the total number of data packets sent by the PLE or over the PVC/VC. ITU-T Rec. X.283 | ISO/IEC 10733 dataPacketsSent.

x25VCStatsDataPacketsReceived

Counter of the total number of data packets received by the PLE or over the PVC/VC. ITU-T Rec. X.283 | ISO/IEC 10733 dataPacketsReceived.

x25VCStatsProviderInitiatedDisconnects

Counter for the provider initiated disconnect events which generate communication alarm notifications. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsRemotelyInitiatedResets

Counter associated with the remotely initiated reset event which generates a communication alarm notification. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsDataRetranmissionTimerExpiries

Counter of the number of expires of timer T25. Returns zero if the option is not implemented. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsProviderInitiatedResets

Counter associated with the provider initiated reset event which generates a communication alarm notification. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsResetTimeouts

Counter of the number of timer T22 expiries experienced by the PLE or over the PVC/VC. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsRemotelyInitiatedRestarts

Counter of the number of remotely initiated restarts. This is the total number of remotely initiated (including provider initiated) restarts experienced by the PLE, including the restart associated with bringing up the PDE interface. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsInterruptPacketsSent

Counter of the number of interrupt packets sent by the PLE or over the PVC/VC. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsInterruptPacketsReceived

Counter of the number of interrupt packets received by the PLE or over the PVC/VC. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsInterruptTimerExpiries

Counter of the number of expiries of timer T26 experienced by the PLE or over the PVC/VC. ITU-T Rec. X.283 | ISO/IEC 10733.

x25VCStatsX25SegmentsSent

Value for count of X.25 Segments Received. ITU-T Rec. X.283 | but not ISO/IEC 10733.

x25VCStatsX25SegmentsReceived

Value for count of X.25 Segments Sent. ITU-T Rec. X.283 | but not ISO/IEC 10733.


6.8 X.25 Permanent Virtual Circuit (PVC) Configuration Tableh

The X.25 Permanent Virtual Circuit (PVC) Configuration Table, x25PVCConfigTable, is a table that provides specific configuration information for permanent virtual circuits (PVC) belonging to the various X.25 packet layer entities (PLE).

An entry exists for each Permanent Virtual Circuit. It may be both created and deleted by management stations.

For DTEs, when an entry is created, the protocol machine shall be reinitialized and a reset PDU shall be transmitted with a cause code of DTE originated (encoded as 00000000) and a diagnostic code of DTE operational (161) shall be transmitted. When the entry is deleted, the protocol machine shall be reinitialized and a reset PDU with cause code of DTE originated (encoded as 00000000) and a diagnostic code of DTE not operational (162) shall be transmitted.

For DCEs, when an entry is created, the protocol machine shall be re-initialized and a reset PDU shall be transmitted. A cause code of remote DTE Operational (encoded as X000 1001) or Network Operational (encoded as X000 1111) may, for example, be included. When the entry is deleted the protocol machine shall be reinitialized and a reset PDU shall be transmitted. A cause code of Out of Order (encoded as X000 0001) or Network Out of Order (encoded as X001 1101) may, for example, be included.

ITU-T Rec. X.283 | ISO/IEC 10742.

  • x25PVCConfigId
  • x25PVCConfigChannel
  • x25PVCConfigRowStatus

6.9 X.25 Switched Virtual Circuit (SVC) Configuration Table

The X.25 Switched Virtual Circuit (SVC) Configuration Table, x25PVCConfigTable, is a table that provides specific configuration information for switched virtual circuits (SVC) belonging to the various X.25 packet layer entities (PLE).

x25SVCConfigId
x25SVCConfigChannel
x25SVCConfigDirection

The direction (incoming(0) or outgoing(1)) of the call. ISO/IEC 10733 : direction.

x25SVCConfigRemoteDTEAddress

The DTE Address of the remote DTE. In the case of an outgoing call, this is the remote DTE address from the called address of the transmitted call request packet. In the case of an incoming call, it is the calling address from the received call request packet. ISO/IEC 10733 remoteDTEAddress.

x25SVCConfigThroughputClass

The actual through class in used for the call. For SVCs this is the result of negotiation. ISO/IEC 10733 : throughputClass.

x25SVCConfigRedirectReason

The reason for call redirect. The zero value indicates that the call was not redirected. ISO/IEC 10733 : redirectReason.

x25SVCConfigOriginallyCalledAddress

The originally called address. ISO/IEC 10733 : originallyCalledAddress.

x25SVCConfigCallingAddressExtension

The contents of the calling address extension field.

In the OSI context, this will always be an NSAP address but in other uses it may not. In any case, it may be null, for example, when used by ISO 8473.

x25SVCConfigCalledAddressExtension

The contents of the called address extension field.

In the OSI context, this will always be an NSAP address but in other uses it may not. In any case, it may be null, for example, when used by ISO 8473.


7 Allowable Sequence of NLI Primitives


7.1 Opening a Connection


7.2 Data Transfer


7.3 Closing a Connection


7.4 Listening


7.5 PVC Operation


Appendix A NLI Header Files

Applications using the Network Layer Interface (NLI) need to include several system header files:


A.1 X.25 Protocol Primitive Header

<errno.h>
<sys/types.h>
<sys/ioctl.h>
<sys/stropts.h>
<sys/snet/x25_proto.h>

Note that on IRIS SX.25 this file is located in <sys/snet/x25_proto.h>. Note that on Solaris X.25 this file is located in <sys/netx25/x25_proto.h>.

#ifndef __NETX25_X25_PROTO_H__
#define __NETX25_X25_PROTO_H__

#include <stdint.h>

/* From Solstice X.25 documentation:
 *
 * The LSAP is defined by the lsapformat structure.  The members of the
 * lsapformat structure are:
 *
 * lsap_len:    This gives the length of the DTE address, the MAC+SAP address,
 *              or the LCI in semi-octets.  For example, for Ethernet, the
 *              length is always 14 to indicate the MAC (12 semi-octets), plus
 *              SAP (2 semi-octets).  The SAP always follows the MAC address.
 *              The DTE can be up to 15 decimal digits unless X.25(88) and
 *              TO/NPI (Type Of Address/Numbering Plan Identification)
 *              addressing is being used, when it can be up to 17 decimal
 *              digits.  For an LCI the length is 3.
 *
 *              The length of the DTE address or LSAP as two BCD digits per
 *              byte, right justified.  An LSAP is always 14 digits long.  A
 *              DTE address can be up to 15 decimal digits unless X.25(88) and
 *              TOA/NPI addressing is used, in which case it can be up to 17
 *              decimal digits.  A PVC_LCI is 3 digits long (hexadecimal,
 *              0-4095).  For TOA/NPI the TOA is:
 *
 *              0000 0 Network-dependent number or unknown
 *              0001 1 International number
 *              0010 2 National number
 *              0011 3 Network specific number (for use in private networks)
 *              0100 4 Complementary address without main address.
 *              0101 5 Alernative address.
 *
 *              NPI for other than Alternative Address is:
 *
 *              0000 0 Network-dependent number or unknown
 *              0001 1 Rec. E.164 (digital)
 *              0010 2 Rec. E.164 (analog)
 *              0011 3 Rec. X.121
 *              0100 4 Rec. F.69 (telex numbering plan)
 *              0101 5 Private numbering plan (for private use only)
 *
 *              NPI when TOA is Alternative Address is:
 *
 *              0000 0 Character string coding to ISO/IEC 646.
 *              0001 1 OSI NSAP address coded per X.213/ISO 8348.
 *              0010 2 MAC address per IEEE 802.
 *              0011 3 Internet Address per RFC 1166. (i.e. an IPv4 address)
 *
 *
 * lsap_add:    The DTE address, LSAP or PVC_LCI as two BCD digtis per byte,
 *              right justified.
 */
#define LSAPMAXSIZE             9

struct lsapformat {
        uint8_t lsap_len;
        uint8_t lsap_add[LSAPMAXSIZE];
};

/* From Solstice X.25 documentation:
 *
 * Addressing is defined by the xaddrf structure.  The members of the xaddrf
 * structure are:
 *
 * link_id:     Holds the link number as a uint32_t.  By default, link_id has
 *              a value of 0xFF.  When link_id is 0xFF, X.25 attempts to match
 *              the called address with an entry in a routing configuration
 *              file.  If it cannot find a match, it routes the call over the
 *              lowest numbered WAN link.
 *
 *              Note that IRIS SX.25 uses sn_id here instead of link_id.
 *
 * aflags:      Specifies the options required or used by the subnetwork to
 *              encode and interpret addresses.  These take on of these values:
 *
 *              NSAP_ADDR   0x00    NSAP field contains OSI-encoded NSAP
 *                                  address.
 *              EXT_ADDR    0x01    NSAP field contains non-OSI-encoded
 *                                  extended address.
 *              PVC_LCI     0x02    NSAP field contains a PVC number.
 *
 *              When the NSAP field is empty, aflags has the value 0.
 *
 * DTE_MAC:     The DTE address or LSAP as two BCD digits per byte, right
 *              justified, or the PVC_LCI as three BCD digits with two digits
 *              per byte, right justified.
 *
 * nsap_len:    The length in semi-octets of the NSAP as two BCD digits per
 *              byte, right justified.
 *
 * NSAP:        The NSAP or address extension (see aflags) as two BCD digits
 *              per byte, right justified.
 */
#define NSAPMAXSIZE 20
struct xaddrf {
        uint32_t link_id;
        unsigned char aflags;
#define EXT_ADDR        0x00            /* X.121 subaddress */
#define NSAP_ADDR       0x01            /* NSAP address */
#define PVC_LCI         0x02            /* PVC LCI number 0-4095 3 semi-octets */
        struct lsapformat DTE_MAC;      /* X.121 DTE address or IEEE 802 MAC */
        unsigned char nsap_len;
        unsigned char NSAP[NSAPMAXSIZE];
};

#define MAX_NUI_LEN     64
#define MAX_RPOA_LEN     8
#define MAX_CUG_LEN      2
#if 1
#define MAX_FAC_LEN     32
#else
#define MAX_FAC_LEN     109
#endif
#define MAX_TARRIFS      4
#define MAX_CD_LEN      (MAX_TARRIFS * 4)
#define MAX_SC_LEN      (MAX_TARRIFS * 8)
#define MAX_MU_LEN      16

/*
 * Extra format (facilities) structure from Solstice X.25 and IRIS SX.25
 * documentation.
 */
struct extraformat {
        unsigned char fastselreq;
        unsigned char restrictresponse;
        unsigned char reversecharges;
        unsigned char pwoptions;
#define NEGOT_PKT       0x01    /* packet size negotiable */
#define NEGOT_WIN       0x02    /* window size negotiable */
#define ASSERT_HWM      0x04    /* concatenation limit assert */
        unsigned char locpacket;
        unsigned char rempacket;
#define DEF_X25_PKT     7       /* the standard default packet size */
        unsigned char locwsize;
        unsigned char remwsize;
#define DEF_X25_WIN     2       /* the standard default window size */
        int nsdulimit;
        unsigned char nui_len;
        unsigned char nui_field[MAX_NUI_LEN];
        unsigned char rpoa_len;
        unsigned char rpoa_field[MAX_RPOA_LEN];
        unsigned char cug_type;
#define CUG             1       /* closed user group, up to four semi-octets */
#define BCUG            2       /* bilateral CUG (two members only), for semi-octets */
        unsigned char cug_field[MAX_CUG_LEN];
        unsigned char reqcharging;
        unsigned char chg_cd_len;
        unsigned char chg_cd_field[MAX_CD_LEN];
        unsigned char chg_sc_len;
        unsigned char chg_sc_field[MAX_SC_LEN];
        unsigned char chg_mu_len;
        unsigned char chg_mu_field[MAX_MU_LEN];
        unsigned char called_add_mod;
        unsigned char call_redirect;
        struct lsapformat called;
        unsigned char call_deflect;
        unsigned char x_fac_len;
        unsigned char cq_fac_len;
        unsigned char cd_fac_len;
        unsigned char fac_field[MAX_FAC_LEN];
};

/*
 * QOS format structure: from Solstice X.25 and IRIS SX.25 documentation.
 */

#define MAX_PROT 32

struct qosformat {
        unsigned char reqtclass;
        unsigned char locthroughput;
        unsigned char remthroughput;
        unsigned char reqminthruput;
        unsigned char locminthru;
        unsigned char remminthru;
        unsigned char reqtransitdelay;
        unsigned short transitdelay;
        unsigned char reqmaxtransitdelay;
        unsigned short acceptable;
        unsigned char reqpriority;
        unsigned char reqprtygain;
        unsigned char reqprtykeep;
        unsigned char prtydata;
        unsigned char prtygain;
        unsigned char prtykeep;
        unsigned char reqlowprtydata;
        unsigned char reqlowprtygain;
        unsigned char reqlowprtykeep;
        unsigned char lowprtydata;
        unsigned char lowprtygain;
        unsigned char lowprtykeep;
        unsigned char protection_type;
#define PRT_SRC         1   /* source address specific */
#define PRT_DST         2   /* destination address specific */
#define PRT_GLB         3   /* globally unique */
        unsigned char prot_len;
        unsigned char lowprot_len;
        unsigned char protection[MAX_PROT];
        unsigned char lowprotection[MAX_PROT];
        unsigned char reqexpedited;
        unsigned char reqackservice;
#define RC_CONF_DTE     1
#define RC_CONF_APP     2
        struct extraformat xtras;
};

/*
 * Diagnostic codes from Solstice X.25 and IRIS SX.25 documentation.   Note
 * that the values themselves are from ISO/IEC 8208 and are mapped from X.25
 * cause and diagnostic codes as described in ISO/IEC 8878.
 */
/*
 * To identify the originator in N_RI and N_DI messages
 */
#define NS_USER                 0x01
#define NS_PROVIDER             0x02

/*
 * Reason when the originator is NS Provider
 */
#define NS_GENERIC              0xe0
#define NS_DTRANSIENT           0xe1
#define NS_DPERMENEN            0xe2
#define NS_TUNSPECIFIED         0xe3
#define NS_PUNSPECIFIED         0xe4
#define NS_QOSNATRANSIENT       0xe5
#define NS_QOSNAPERMENENT       0xe6
#define NS_NSAPTUNREACHABLE     0xe7
#define NS_NSAPPUNREACHABLE     0xe8
#define NS_NSAPPUNKNOWN         0xeb

/*
 * Reason when the originator is NS User
 */
#define NU_GENERIC              0xf0
#define NU_DNORMAL              0xf1
#define NU_DABNORMAL            0xf2
#define NU_DINCOMPUSERDATA      0xf3
#define NU_TRANSIENT            0xf4
#define NU_PERMANENT            0xf5
#define NU_QOSNATRANSIENT       0xf6
#define NU_QOSNAPERMENENT       0xf7
#define NU_INCOMPUSERDATA       0xf8
#define NU_BADPROTID            0xf9

/*
 * To specify the reason when the originator is NS Provider in N_RI messages
 */
#define NS_RUNSPECIFIED         0xe9
#define NS_RCONGESTION          0xea

/*
 * To specify the reason when the originator is NS User in N_RI messages
 */
#define NU_RESYNC               0xfa

/*
 * X.25 Primitive structures taken from Solstice X.25 documentation.
 */

#define XL_CTL      0
#define XL_DAT      1

#define N_CI        0

struct xcallf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_CI */
        int conn_id;                    /* The connection id returned in Connection Response or
                                           Disconnect */
        unsigned char CONS_call;        /* When set, indicates a CONS call */
        unsigned char negotiate_qos;    /* When set, negotiate facilities, etc., or else use
                                           defaults */
        struct xaddrf calledaddr;       /* called address */
        struct xaddrf callingaddr;      /* calling address */
        struct qosformat qos;           /* facilities and CONS qos: if negotiate qos is set */
        /* Note the data part of the message contains the Call User Data (CUD), if any. */
};

#define N_CC        1

struct xccnff {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_CC */
        int conn_id;                    /* The connection id from the associated indication. */
        unsigned char CONS_call;        /* When set, indicate CONS call */
        unsigned char negotiate_qos;    /* When set, negotiate facilities, etc., else use indicated 
                                           values. */
        struct xaddrf responder;        /* responding address */
        struct qosformat rqos;          /* Facilities and CONS qos if negotiate_qos is set. */
        /* Note the data part of the message contains the CUD, if any. */
};

#define N_Data      2

struct xdataf {
        unsigned char xl_type;          /* always XL_DAT */
        unsigned char xl_command;       /* always N_Data */
        unsigned char More;             /* set when more data is required to complete the nsdu */
        unsigned char setDbit;          /* set when data carries X.25 D-bit */
        unsigned char setQbit;          /* set when data carries X.25 Q-bit */
        /* Note the data part of the message contains user data */
};

#define N_DAck      3

struct xdatacf {
        unsigned char xl_type;          /* always XL_DAT */
        unsigned char xl_command;       /* always N_DAck */
        /* No data part */
};

#define N_EData     4

struct xedataf {
        unsigned char xl_type;          /* always XL_DAT */
        unsigned char xl_command;       /* always N_EData */
        /* Note the data part of the message contains user data */
};

#define N_EAck      5

struct xedatacf {
        unsigned char xl_type;          /* always XL_DAT */
        unsigned char xl_command;       /* always N_EAck */
        /* No data part */
};

#define N_RI        6

struct xrstf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_RI */
        unsigned char originator;       /* originator and reason mapped */
        unsigned char reason;           /* from X.25 cause/diag in indications */
        unsigned char cause;            /* X.25 cause byte */
        unsigned char diag;             /* X.25 diagnostic byte */
        /* No data part */
};

#define N_RC        7

struct xrscf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_RC */
        /* No data part */
};

#define N_DI        8

struct xdiscf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_DI */
        unsigned char originator;       /* originator and reason mapped */
        unsigned char reason;           /* from X.25 cause/diag in indications */
        unsigned char cause;            /* X.25 cause byte */
        unsigned char diag;             /* X.25 diagnostic byte */
        int conn_id;                    /* the connection id (for reject only) */
        unsigned char indicated_qos;    /* when set, facilities indicated */
        struct xaddrf responder;        /* CONS responder address */
        struct xaddrf deflected;        /* deflected address */
        struct qosformat qos;           /* if indicated_qos is set, holds facilities and CONS qos */
        /* The data part of the message contains the clear user data, if any. */
};

#define N_DC        9

struct xdcnff {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_DC */
        unsigned char indicated_qos;    /* when set, facilities indicated */
        struct qosformat qos;           /* if indicated_qos is set, holds facilities and CONS qos */
        /* No data part */
};

#define N_Abort     10

struct xabortf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_Abort */
        /* No data part */
};

#define N_Xlisten   11

struct xlistenf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_Xlisten */
        int lmax;                       /* maximum number of CI's at a time */
        int l_result;                   /* result flag */
        /* Data part contains called user data. */
};

#define X25_DONTCARE    0       /* The listener ignores the CUD of Address, l_culength and
                                   l_cubytes, or l_type, l_length and l_add are ommited. */
#define X25_IDENTITY    1       /* The listener match is made only if all bytes of the CUD or
                                   Address field are the same as the supplied l_cubytes or l_add */
#define X25_STARTSWITH  2       /* The listener match is made only if the leading bytes of the CUD
                                   or Address field are the same as the supplied l_cubytes or l_add 
                                 */
struct l_cu {
        unsigned char l_cumode;         /* CUD mode as above. */
        unsigned char l_culength;       /* This is the length of the CUD in octets for a field
                                           match.  If l_culength is zero, l_cubytes is omitted.
                                           Currently, the range for l_culength is zero to 16
                                           inclusive.  The application still has to check the full
                                           CUD field. */
        unsigned char l_cubytes[0];     /* Of length l_culength, this is the string of bytes sought 
                                           in the CUD field when a matching mode is specified. */
};
struct l_add {
        unsigned char l_mode;           /* Address mode as above. */
        unsigned char l_type;           /* This is the type of the address entry, and it can have
                                           to values. */
#define X25_DTE         0
#define X25_NSAP        1
        unsigned char l_length;         /* This is the length of the address l_add in
                                           semi-octets--the common format for X.25 DTE addresses
                                           and NSAPs.  If l_length is zero, then l_add is omitted.
                                           The maximum values for l_length are 15 for X25_DTE and
                                           40 for X25_NSAP. */
        unsigned char l_add[0];         /* Of length l_length, this contains the address in
                                           semi-octets. */
};

#define N_Xcanlis   12

struct xcanlisf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_Xcanlis */
        int c_result;                   /* result flag */
        /* No data part */
};

#define N_PVC_ATTACH    13

struct pvcattf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_PVC_ATTACH */
        unsigned short lci;             /* logical channel */
#if 0
        unsigned long sn_id;            /* subnetwork identifier */
#else
        unsigned int sn_id;             /* subnetwork identifier */
#endif
        unsigned char reqackservice;    /* receipt acknowledgement 0 for next parameter implies use 
                                           of default */
        unsigned char reqnsdulimit;
        int nsdulimit;
        int result_code;                /* Nonzero - error */
};

#define N_PVC_DETACH    14

struct pvcdetf {
        unsigned char xl_type;          /* always XL_CTL */
        unsigned char xl_command;       /* always N_PVC_DETACH */
        int reason_code;                /* reports why */
};

typedef struct xhdrf {
        unsigned char xl_type;          /* XL_CTL/XL_DAT */
        unsigned char xl_command;       /* Command */
} S_X25_HDR;

/*
 * X.25 primitives union from Solstice X.25 and IRIS SX.25 documentation.  Both
 * documetnation sources contain errors (maker with "[sic]" below).
 */
typedef union x25_primitives {
        struct xhdrf xhdr;              /* header */
        struct xcallf xcall;            /* connect request/indication */
        struct xccnff xccnf;            /* connect confirm/response */
        struct xdataf xdata;            /* normal, q-bit or d-bit data */
        struct xdatacf xdatac;          /* data ack */
        struct xedataf xedata;          /* expedited data */
        struct xedatacf xedatac;        /* expedited data ack */
        struct xrstf xrst;              /* reset request/indication */
        struct xrscf xrsc;              /* reset confirm/response */
        struct xrscf xrscf;             /* reset confirm/response [sic] */
        struct xdiscf xdisc;            /* disconnect request/indication */
        struct xdcnff xdcnf;            /* disconnect confirm */
        struct xabortf xabort;          /* abort indication */
        struct xabortf abort;           /* abort indication [sic] */
        struct xlistenf xlisten;        /* listen command/response */
        struct xcanlisf xcanlis;        /* cancel command/response */
        struct pvcattf pvcatt;          /* PVC attach */
        struct pvcdetf pvcdet;          /* PVC detach */
} x25_types;

#endif                          /* __NETX25_X25_PROTO_H__ */

A.2 X.25 Input-Output Control Header

<errno.h>
<sys/types.h>
<sys/ioctl.h>
<sys/stropts.h>
<sys/snet/x25_proto.h>
<sys/snet/x25_control.h>

Note that on IRIS SX.25 this file is located in <sys/snet/x25_control.h>. Note that on Solaris X.25 this file is located in <sys/netx25/x25_control.h>.

#ifndef __NETX25_X25_CONTROL_H__
#define __NETX25_X25_CONTROL_H__

/* linkid:              the number of the link.
 *
 * network_state:       a code fining the network state.  The codes are as
 *                      follows:
 *
 *                      1 - connecting to DXE
 *                      2 - connecte resolving DXE
 *                      3 - random wait started
 *                      4 - connected and resolved DXE
 *                      5 - DTE restart request
 *                      6 - waiting link disconnect reply
 *                      7 - buffer to enter WtgRES
 *                      8 - buffer to enter L3 restarting
 *                      9 - buffer to enter L_disconnect
 *                      10 - registration request
 *
 * mon_array:           the array containing the statistics mon_array is
 *                      defined in the file x25_control.h
 */
struct perlinkstats {
        uint32_t linkid;                        /**< link id (ppa) */
        int network_state;                      /**< network state */
        uint32_t mon_array[link_mon_size];      /**< L3 per link monitor array */
};

/* version:             the version of NLI supported by the X.25 multiplexor.
 */
struct nliformat {
        unsigned char version;          /**< NLI version number */
};

enum {
        cll_in_v = 1,
#define cll_in_v        cll_in_v
        cll_out_v,
#define cll_out_v       cll_out_v
        caa_in_v,
#define caa_in_v        caa_in_v
        caa_out_v,
#define caa_out_v       caa_out_v
        dt_in_v,
#define dt_in_v         dt_in_v
        dt_out_v,
#define dt_out_v        dt_out_v
        ed_in_v,
#define ed_in_v         ed_in_v
        ed_out_v,
#define ed_out_v        ed_out_v
        rnr_in_v,
#define rnr_in_v        rnr_in_v
        rnr_out_v,
#define rnr_out_v       rnr_out_v
        rr_in_v,
#define rr_in_v         rr_in_v
        rr_out_v,
#define rr_out_v        rr_out_v
        rst_in_v,
#define rst_in_v        rst_in_v
        rst_out_v,
#define rst_out_v       rst_out_v
        rsc_in_v,
#define rsc_in_v        rsc_in_v
        rsc_out_v,
#define rsc_out_v       rsc_out_v
        clr_in_v,
#define clr_in_v        clr_in_v
        clr_out_v,
#define clr_out_v       clr_out_v
        clc_in_v,
#define clc_in_v        clc_in_v
        clc_out_v,
#define clc_out_v       clc_out_v
        octets_in_v,
#define octetst_in_v    octetst_in_v
        octets_out_v,
#define octets_out_v    octets_out_v
        rst_timeouts_v,
#define rst_timeouts_v  rst_timeouts_v
        ed_timeouts_v,
#define ed_timeouts_v   ed_timeouts_v
        prov_rst_in_v,
#define prov_rst_in_v   prov_rst_in_v
        rem_rst_in_v,
#define rem_rst_in_v    rem_rst_in_v
        perVCmon_size
#define perVCmon_size   perVCmon_size
};

/* rem_addr:            the called address if its an outgoing call, or the
 *                      calling address for incoming calls.
 *
 * xu_ident:            the link identifier
 *
 * process_id:          the relevant user id
 *
 * lci:                 the logical channel identifier
 *
 * xstate:              the VC state
 *
 * xtag:                the VC check record
 *
 * ampvc:               set to 1 if this is a PVC
 *
 * call_direction:      0 indicates incoming call, 1 outgoing call
 *
 * perVC_stats:         an array containing the per-virtual channel circuit
 *                      statistics.  The array is defined in the x25_control.h
 *                      file.
 */
struct vcinfo {
        struct xaddrf rem_addr;
        /* struct xaddrf loc_addr; */
        uint32_t xu_ident;              /* link identifier */
        uint32_t process_id;            /* relevant user id */
        unsigned short lci;             /* logical channel id */
        unsigned char xstate;           /* VC state */
        unsigned char xtag;             /* VC check record */
        unsigned char ampvc;            /* true if is a PVC */
        unsigned char call_direction;   /* 0, incoming; 1, outgoing */
        unsigned char domain;           /* vctype */
        int perVC_stats[perVCmon_size]; /* per-VC statistics */
};

/* entries:             contains the structure for the returned mapping
 *                      entries.
 *
 * first_ent:           informs the X.25 multiplexor where to start or
 *                      restart the table read.  It should intially be set to
 *                      zero 0, to indicate starting at the beginning of the
 *                      table.  On return, it points to the next entry.
 *
 * num_ent:             indicate the number of mapping entries returned in the
 *                      entries member.  It should be set to 0 before maing
 *                      the ioctl.
 */
struct pvcmapf {
        struct pvcconff entries[MAX_PVC_ENTS];  /* data buffer */
        int first_ent;                  /* where to start search */
        unsigned char num_ent;          /* number entries returned */
};

// int N_getstats[mon_size];
enum {
        cll_in_g = 0,
        caa_in_g,
        caa_out_g,
        ed_in_g,
        ed_out_g,
        rnr_in_g,
        rnr_out_g,
        rr_in_g,
        rr_out_g,
        rst_in_g,
        rst_out_g,
        rsc_in_g,
        rsc_out_g,
        clr_in_g,
        clr_out_g,
        clc_in_g,
        clc_out_g,
        cll_coll_g,
        cll_uabort_g,
        rjc_buflow_g,
        rjc_coll_g,
        rjc_failNRS_g,
        rjc_lstate_g,
        rjc_nochnl_g,
        rjc_nouser_g,
        rjc_remote_g,
        rjc_u_g,
        dg_in_g,
        dg_out_g,
        p4_ferr_g,
        rem_perr_g,
        rem_ferr_g,
        res_in_g,
        res_out_g,
        vcs_labort_g,
        r23exp_g,
        l2conin_g,
        l2conok_g,
        l2conrej_g,
        l2refusal_g,
        l2lzap_g,
        l2r20exp_g,
        l2dxeexp_g,
        l2dxebuf_g,
        l2noconfig_g,
        xiffnerror_g,
        xintdisc_g,
        xifaborts_g,
        PVCusergone_g,
        max_opens_g,
        vcs_est_g,
        bytes_in_g,
        bytes_out_g,
        dt_in_g,
        dt_out_g,
        res_conf_in_g,
        res_conf_out_g,
        reg_in_g,
        reg_out_g,
        reg_conf_in_g,
        reg_conf_out_g,
        l2r28exp_g,
        mon_size
};

struct N_getstats {
        int cll_in;             /**< calls received and indicated */
        int caa_in;             /**< call established outgoing */
        int caa_out;            /**< call established incoming */
        int ed_in;              /**< interrupts recv */
        int ed_out;             /**< interrupts sent */
        int rnr_in;             /**< receiver not ready recv */
        int rnr_out;            /**< receiver not ready sent */
        int rr_in;              /**< receiver ready recv */
        int rr_out;             /**< receiver ready sent */
        int rst_in;             /**< resets recv */
        int rst_out;            /**< resets sent */
        int rsc_in;             /**< restart confirms recv */
        int rsc_out;            /**< restart confirms sent */
        int clr_in;             /**< clears recv */
        int clr_out;            /**< clears sent */
        int clc_in;             /**< clear confirms recv */
        int clc_out;            /**< clear confirms sent */
        int cll_coll;           /**< call collision count (not rjc) */
        int cll_uabort;         /**< calls aborted by user b4 sent */
        int rjc_buflow;         /**< calls rejected no buffs b4 sent */
        int rjc_coll;           /**< calls rejected collision DCE mode */
        int rjc_failNRS;        /**< calls rejected netative NRS response */
        int rjc_lstate;         /**< calls rejected link disconnecting */
        int rjc_nochnl;         /**< calls rejected no lcns left */
        int rjc_nouser;         /**< in call but no user on NSAP */
        int rjc_remote;         /**< call rejected by remote responder */
        int rjc_u;              /**< call rejected by NS user */
        int dg_in;              /**< DIAG packets recv */
        int dg_out;             /**< DIAG packets sent */
        int p4_ferr;            /**< format errors in P4 */
        int rem_perr;           /**< remote protocol errors */
        int rem_ferr;           /**< restart format errors */
        int res_in;             /**< restarts recv (inc DTE/DXE) */
        int res_out;            /**< restarts sent (inc DTE/DXE) */
        int vcs_labort;         /**< circtuis aborted via link event */
        int r23exp;             /**< circuits hung by r23 expiry */
        int l2conin;            /**< Link level connect established */
        int l2conok;            /**< LLC connections accepted */
        int l2conrej;           /**< LLC connections rejected */
        int l2refusal;          /**< LLC connect requests refused */
        int l2lzap;             /**< operator requests to kill link */
        int l2r20exp;           /**< R20 transmission expiry */
        int l2dxeexp;           /**< DXE connect expiry */
        int l2dxebuf;           /**< DXE resolv abort - no buffers */
        int l2noconfig;         /**< no config base - error */
        int xiffnerror;         /**< upper interface bad M_PROTO type */
        int xintdisc;           /**< internal disconnect events */
        int xifaborts;          /**< interface abort_vc called */
        int PVCusergone;        /**< count of non-user interactions */
        int max_opens;          /**< highest number of simultaneous opens */
        int vcs_est;            /**< VCs established since reset */
        int bytes_in;           /**< data bytes recv */
        int bytes_out;          /**< data bytes sent */
        int dt_in;              /**< data packets recv */
        int dt_out;             /**< data packets sent */
        int res_conf_in;        /**< restart confirms recv */
        int res_conf_out;       /**< restart confirms sent */
        int reg_in;             /**< registration requests recv */
        int reg_out;            /**< registration requests sent */
        int reg_conf_in;        /**< registration confirms recv */
        int reg_conf_out;       /**< registration confirms sent */
        int l2r28exp;           /**< R28 transmission expiries */
};

struct pervcinfo {
        struct xaddrf rem_addr;
        uint32_t xu_ident;
        uint32_t process_id;
        unsigned short lci;
        unsigned char xstate;
        unsigned char xtag;
        unsigned char ampvc;
        unsigned char call_direction;
        unsigned char domain;
        uint32_t perVC_stats[perVCstat_size];
        /* compatibility */
        unsigned char vctype;
        struct xaddrf loc_addr;
        uint32_t start_time;
};

struct vcstatsf {
        int first_ent;          /**< where to start search */
        unsigned char num_ent;  /**< number entries returned */
        struct pervcinfo vc;    /**< data buffer, extendable by malloc overlay */
};

struct vcstatusf {
        struct vcinfo vcs[MAX_VC_ENTS];
        int first_ent;
        unsigned char num_ent;
};

#define X25_LLC         1       /**&l