[asterisk-users] T.38 not working - help needed with log interpretation

[Frederic Van Espen]

Hi,

On Mon, Dec 15, 2014 at 9:03 AM, Recursive <lists at binarus.de> wrote:
>
> I would be grateful if you could refer to my message from some minutes ago. I have provided all the details there.

According to the detailed trace asterisk is indeed retransmitting SIP
OK messages:

<snip>
Session Initiation Protocol (200)
    Status-Line: SIP/2.0 200 OK
        Status-Code: 200
        [Resent Packet: True]
        [Suspected resend of frame: 28887]
        [Request Frame: 28888]
        [Response Time (ms): 592]
</snip>

It does this although the other endpoint does respond with an ACK
message. My guess is that there's something in the ACK messages that
asterisk does not like and thus discards. The 32 seconds you mention
correlate to the default 32 seconds Timer-B value. Have you tried to
enable SIP debugging and asterisk debugging? There should be a clue in
the asterisk debug log. You can try increasing the timerb value in
sip.conf to confirm this:
quote from sip.conf.sample
;timerb=32000                   ; Call setup timer. If a provisional
response is not received
                                ; in this amount of time, the call
will autocongest
                                ; Defaults to 64*timert1


Apart from that, I would indeed advise to remove the Answer and
Progress applications from the dialplan. Just dial the peer and let it
handle the session.

Cheers,

Frederic