[asterisk-users] Send SIP 100 Trying instead of 183 Session Progress

[Johansson Olle E]

21 dec 2007 kl. 22.24 skrev Richard Revels:

> You are probably running into the problem described below.  Below  
> that is a link to the original document with the code patch.  I put  
> it on a PRI box we use inhouse and it took care of the 183 before a  
> busy for me.  However, this is a box we use inhouse.  I've never put  
> it on anything in production.  Your mileage may vary
>
> >>>>>>>>>>>>>>>>>>>>>>
> gday guys (n'gals).
>
> I have a third party SIP platform which generates outbound calls via
> asterisk to ISDN (Australia - so thats ETSI ISDN).   This platform  
> doesn't
> really like inband signalling on outbound calls (ie getting 183's  
> with SDP
> -- its fine with 180 Ringing etc...)
>
> Having had a bit of a silly time with the sip.conf variable
> progressinband=never,no,yes (arg!) I dug a little deeper into the  
> chan_sip
> code.
>
> It appears on a SIP->Zap call the ISDN channel is opened, and before  
> you can
> say 'boo' sip_write() in chan_sip is called.... this appears to  
> occurs prior
> to any ISDN signalling (such as PRI_EVENT_PROCEEDING etc..)
>
> sip_write doesn't seem to care at all what progressinband is set to,  
> and if
> it gets a frame when the SIP channel is not in AST_STATE_UP it  
> generates a
> 183 with SDP (then sets SIP_PROGRESS_SENT)
>
> Does this behaviour seem strange?   I'm not really sure if this is a  
> bug, a
> 'its just like that' thing, or something strange with our ISDN that is
> unusual?
>
> In an ideal world (for me anyway... *grin*) I would think that
> progressinband=never (or even progressinband=no) would mean that 180
> Ringing, 486 Busy etc would be used and 183 Session Progress with  
> SDP would
> not...

I don't think progressinband controls early media (audio to caller  
before call setup)
but how indications should be sent (in audio=inband). If we get early  
media from
the callee leg of the call, we have to relay it always.

If you get early media signalling in SIP and don't have early media on  
the outbound
call leg, then there's a bug and you should open a bug in the bug  
tracker so we
can resolve it. For license reasons, we can't handle patches on the  
mailing list,
we have to get them through the bug tracker.

I really appreciate your help in resolving this issue, as you clearly  
have a lot of
insight in the situation. Please open a bug on the bug tracker and  
we'll meet
you there!

Thanks,
/Olle

---
* Olle E. Johansson - oej at edvina.net
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