[asterisk-users] Asterisk receiving 415 Unsupported Media Type upon T.38 invite behaving absolutely weird.

[Benoit Panizzon]

Hello

I am hunting Fax Problems.

Now I have come across a situation on which, I fear asterisk behaves in
a wrong manner..

A T.38 enabled ATA is connected to the asterisk and receiving a call
from a non T.38 capable endpoint.

The ATA is detecting the CED tone and initiating a T.38 re-invite.
Asterisk forwards that T.38 Re-invite to the non T.38 endpoint.

The non T.38 endpoint answers with 415 Unsupported Media.

From my point of view, Asterisk should now forward this to the ATA so
it can Fallback to G.711. But this does not happen.

What follows next is:

Asterisk issuing Bye to the non T.38 endpoint ending the call.
Asterisk answering 200 Ok to the ATA initiating T.38 (weird!)
Asterisk re-sending an invite T.38 to the NON T.38 endpoint after
ending the call (even weirder). That Endpoint is the outgoing trunk so
it challenges that invite with a 401 challenge, causing the asterisk to
also drop the other leg.

So what's going wrong here? (PCAP attached).

I know, most Endpoints to reply with 488 when fallback to g711 is
required. This one does send 415, which IMHO is also valid.

Any ideas?

Asterisk 13.14.1 in use.

-- 
-Benoît Panizzon-
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