On Tue, Oct 7, 2008 at 1:21 PM, Andy Spitzer <[EMAIL PROTECTED]> wrote: > Woof! > > On Tue, 07 Oct 2008 12:31:43 -0400, M. Ranganathan <[EMAIL PROTECTED]> wrote: > >> then Re-INVITEs using a t38 offer but now >> with a different receive port. However, the session ID for the SDP is >> the same. > > I don't see that. The origin field in the first invite is: > o=AudiocodesGW 714893621 714893506 IN IP4 192.168.6.201 > -----------------------------^ > > And in the second invite is: > o=AudiocodesGW 714893621 714893507 IN IP4 192.168.6.201 > -----------------------------^ > > The session id is the same, and the session version is increased as it is > supposed to be, indicating a change in SDP. > >> Does this mean there are actually separate receive ports >> associated with the same session? > > Nope. Drop the old, open the new. > >> What happens to the data that was destined to port 6000 at this point? >> I ask because in the context of sipxbridge, I want to know whether or >> not to create a second bridge for this port. > > Stop sending to G.711 to 6000. Start sending T.38 to 6002. > >> Second, do I need RTCP support for fax? > > No. T.38 doesn't use RTP. It uses "udptl" which doesn't have the 2nd port > or even number port (if I recall correctly) restrictions of RTP. > > m=image 6002 udptl t38 > --------------^ > > > --Woof! >
Excellent! Yes that all worked as you describe it. In order to get it to work though, I had to do something that I don't fully understand. What is the difference between : Detect T38 on CED vs. Detect T38 on PRE-AMBLE ? The former did the trick, whereas the latter did not. I think I need a quick primer on how T38 works with SIP. If you have a good pointer to SIP + T38, please share it. Thanks! Ranga -- M. Ranganathan _______________________________________________ sipx-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-dev Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev
