[Asterisk-Dev] Asterisk / OpenH323 Bearer-Capability

[Craig Southeren]

On Thu, 02 Sep 2004 16:36:48 -0400
"Aaron S. Joyner" <asjoyner at intrex.net> wrote:

> I'm currently using Asterisk, and working with a provider to setup an 
> H.323 gateway connection.  In the process of setting up the H.323 
> connection, Asterisk (via OpenH323) is sending the wrong 
> Bearer-Capability, as seen here in the output of a call, with "h.323 
> trace 4" set.
> 
> >       IE: Bearer-Capability = {
> >         80 90 a5                                           ...
> >       }
> 
> If I understand it correctly, this is stating that Asterisk is capable 
> of handling more than just data - that OpenH323 is fully capable of 
> passing video codecs, etc.  Unfortunately, I need to reduce what I'm 
> advertising that I'm capable of doing - as it's confusing the remote 
> end.  In a perfect world, I need it to say "80 90 a2" or "80 90 a3".


I don't have a copy of Q.931 handy, so I can't decode exactly what this
means. But the first byte indicate the type of data, and 0x80 means
speech. If it was set to "unrestricted digital" (i.e. video), then the
first byte would be 0x88

From memory, the last byte is used to define what kind of number is
being sent, i.e. whether it is national number or such. To set this byte
in outgoing SETUP PDUs, you will need to override the
H323Endpoint::OnSendSignalSetup function and set the bearer caps as
follows:

BOOL MyH323Connection::OnSendSignalSetup(H323SignalPDU & setupPDU)
{
  // set Q.931 parms
  setupPDU.SetQ931Fields(*this, TRUE, q931Plan, q931Type);
  return H323Connection::OnSendSignalSetup(setupPDU);
}


Hope this helps.

   Craig

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