Asterisk 1.4.32 (Also 1.4.26, 1.4.33) Broadvox ITSP (xxx.xxx.xxx.xxx) Linksys 2102 (yyy.yyy.yyy.yyy) Both peers : canreinvite=yes t38pt_udptl = yes I'm having some trouble getting a T.38 fax call established with Broadvox. During negotiation, Asterisk sends a SIP re-invite (T38 switchover) to Broadvox with the Asterisk server's IP address in the Connection Information (c) instead of the Linksys ATA's IP address. This causes the negotiation to revert back to t38state zero (chan_sip.c: T38_DISABLED), and shortly after the ATA hangs up. What is a bit odd about this, is that Asterisk says it's about to establish a peer to peer UDPTL connection : chan_sip.c: Sending reinvite on SIP '1057817983_43059159 at xxx.xxx.xxx.xxx' - It's UDPTL soon redirected to IP yyy.yyy.yyy.yyy:16468 chan_sip.c: Strict routing enforced for session 1057817983_43059159 at xxx.xxx.xxx.xxx On a known good/working T.38 configured Asterisk PBX elsewhere (with Affinity as the ITSP), I also see the "Strict routing" message, yet T.38 negotiation achieves t38state 5 (chan_sip.c: T38_ENABLED) and calls are successful. I've been comparing Asterisk debug from both systems as well as wireshark captures, but I can't figure out why Asterisk is not sending the Linksys ATA's IP address. Broadvox uses a Sonus switch and gateway with separate IP addresses for SIP and media. Affinity uses "Sippy" (?) with a common IP for SIP and media. I believe I've already covered all the possible configuration scenarios. I just can't get the right detail out of Asterisk to determine if this is an Asterisk issue, or an ITSP issue. Using bug ID#16705 as a guide, I patched this version, as well as downgraded to a known working version, and to the latest 1.4.33.1 which includes several t.38 fixes. https://issues.asterisk.org/view.php?id=16705 Thoughts? Chris