[asterisk-users] asterisk 13.16 / pjsip / t.38: res_pjsip_t38.c:207 t38_automatic_reject: Automatically rejecting T.38 request on channel 'PJSIP/91-00000007'

Michael Maier m1278468 at mailbox.org
Sun Jun 18 01:56:06 CDT 2017

On 06/17/2017 at 02:18 PM, Michael Maier wrote:
> On 06/16/2017 at 04:00 PM, Joshua Colp wrote:
>> On Fri, Jun 16, 2017, at 10:49 AM, Michael Maier wrote:
>> <snip>
>>> t38modem and asterisk are using
>>> m=image 35622 udptl t38
>>>                ^^^^^
>>> Provider uses
>>> m=image 35622 UDPTL t38
>>>                ^^^^^
>>> Could this be a problem? If I'm sending internal only, it's always 
>>> lowercase.
>> Looking at the tests we have we only use 'udptl' as the transport.
>> Without diving deep into the SDP negotiator it is possible that it gets
>> upset at that, as we would only produce 'udptl'. If the SDP negotiator
>> in PJSIP is case sensitive then you'd get a declined stream like you
>> see. Looking at the T.38 examples from the ITU doc also shows it in
>> lowercase, so uppercase is probably not commonly used.
> I can proof, that UDPTL vs. udptl is the problem. After "fixing"
> asterisk and opal both using UDPTL, the negotiation works flawlessly.
> See attached patches.

For opal, the sip patch (src/t38/sipt38.cxx) is enough - the other two
patches aren't necessary. It's only a SIP-problem.


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