Re: [openss7] Hey

[Chuck Winters <cwinters@atl.lmco.com>]

"Brian F. G. Bidulock" wrote:

> Chuck,
>
> Chuck Winters wrote:                     Mon, 18 Jun 2001 18:06:40
> > Brian,
> >     Sorry, for the delay, but I was busy testing a protocol!  It does
> > work.  The times seem to be good so far on a small sample size.  There
> > are a couple of problems though.
> >
> >     1)  sctp_fast_retrans_calc is not passing a debugging feature on
> > line 202
>
> See patch.
>
> >     2)  recvmsg does not return anything in (struct
> > msghdr).msg_name (it's null)
>
> I believe it is normally null for TCP sockets.  On multi-homed SCTP
> it might be an idea to return the actual sender, but it would still
> be one of the addresses returned by getpeername().  It would cost
> time to fill out this for ever message.  UDP fills this out.
>
> It might be an idea to make this a socket option.
>

Accept should return the address of the peer correct?  If that is right,
then there is probably no reason to get the address out of recvmsg.  It
kinda makes sense, unless the peer is sending over a different interface.
Then you may want to get his address at recvmsg.   Just thinking outloud,
anyway ...

>
> >     3)  Something locks up when there is a packet size of 4096.  It
> > locks up after about 5 messages are sent
> >           of that size
>
> It would be good to get some ethereal dumps of this happening.  It
> might have to do with SCTP attempting to fragment data chunks when
> the chunks size is greater than 1/2 of the MTU.  (I presume that
> you have an MTU of 5000 for etherenet.)

I will try to get some today.

>
>
> >
> >     I just started a run on 1,000,000 messages, so we'll see what
> > happens.  The max. data size will be 2048 bytes, so it doesn't lock up.
> >
> >     I still have to implement the rtt stuff into my code.  Maybe
> > tomorrow I will start that so I can begin to tweak some settings.
>
> I eagerly await results.  If you get any strange crashes, try to
> grab an ethereal dump and any logs created.
>
> --
> 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 ¦

I am going on vacation tomorrow, so you will probably not hear anything from
me after today until Tuesday.

Chuck