[Freeswitch-users] Fax T38 problems in proxy media

[Jose Fco. Irles Durá]

Hi, I have sended another email to the list with attachments. I think
that the list not accepts attachments, sorry.

I have several FreeSWITCH's (latest version from deb packages: 1.10.1
-release-12-f9990221e6) and I have problems with faxes in proxy media
(in bypass-media works).
In the sofia.conf.xml I have setted the param t38-passthru=true

If the flow is:
1. Initial INVITE
2. Re-Invite from one of the legs with t38 sdp
Result: works

But if the flow is:
1. Initial INVITE
2. Re-invite from one of the legs changing the media (at answer)
3. Re-invite from one of the other legs with t38 sdp
Result: not works

I tried with "soa_enable=false" without luck.

FreeSWITCH seems that hangs the sip transaction.

This capture is the first reinvite (in the flow, the "showing" line):
https://pastebin.com/raw/X4zrUr4k

This capture is the reinvite with the t38 negotiation sended by the
receiver (Grandstream ATA):
https://pastebin.com/raw/KCXD51aH

And this with the response (200ok) accepting the t38 negotiation):
https://pastebin.com/raw/ifqtPN8L

How I can debug the problem?

Best regards