Re: [openss7] Is CAMA still being implemented right now?

["Brian F. G. Bidulock" <bidulock@openss7.org>]

Patrick,

CAMA is not completely related to SS7, however, in the modern
telephone network LAMA is normally performed by SS7-capable
end offices because they receive the answer-supervision necessary
to generate a bill using SS7 ISUP.  However, CAMA offices still
exists and are necessary in support of CAS switches which do not
support SS7 or which are not equipped with LAMA capabilities.
These switches route AMA calls over toll trunk groups to a
toll switch which performs the billing.  This is normally done
over MF trunk groups which cannot receive answer supervision
because the MF reversal or wink used to spill ANI precludes a
subsequent reversal or wink to indicate answer supervision.
Although special multi-wink MF procedures exist which can return
answer as well as spilling ANI, it may still cause problems due
to operator intercept, recorded announcments, and blue-box fraud
avoidance.  This is why many CAMA offices were also configured
as CAMA/TOPS or CAMA/TSPS switches.

Is it outdated?  Well, no.  If you have SxS or #5XB or SP-1 or
some older DMS-10 or other switches in your network (and there
are a lot of little providers that do) then there is still a
need for CAMA.

A CAMA office is normally also an 800-SSP nowadays.  The CAMA
billing is used to bill 800 numbers.  Many IXC switches can still
be termed as CAMA (as they do centralized billing and only get
a trunk usage record from the LEC AT).  Many Interntional Gateway
switches perform centralized AMA (but normally use sepcial CDR
record formats).

Is the term outdated?  Yes, the term is outdated, but the function
is still peformed a wide array of switches under a different name.

--Brian


Patrick Lam wrote:                           Thu, 07 Jun 2001 11:06:26
>
> Hi all:
> 
> This is a general SS7 question.
> 
> While I am going through Telcordia doc, they implied that CAMA (Central
> Automatic Message Accounting) is pretty much outdated.  Is that true?
> Is is still necessary to implement it?
> 
> Thanks very much in advance,
> 
> Patrick.

-- 
Brian F. G. Bidulock    ¦ The reasonable man adapts himself to the ¦
bidulock@openss7.org    ¦ world; the unreasonable one persists in  ¦
http://www.openss7.org/ ¦ trying  to adapt the  world  to himself. ¦
                        ¦ Therefore  all  progress  depends on the ¦
                        ¦ unreasonable man. -- George Bernard Shaw ¦