[Users] 180 Ringing / 183 Session Progress

Jerome Martin jmartin at longphone.fr
Tue Feb 6 12:06:57 CET 2007


Also note that on ISDN/SIP gateways, you often have many options to
fine-tune this. Like progress indicators mappings, play local tone or
just forward distant, etc.


On Tue, 2007-02-06 at 11:17 +0100, Atle Samuelsen wrote:
> Hi Sam,
> 
> * Sam Lee <sam.lee at super.net.sg> [070206 11:09]:
> > Hey Guys,
> >  
> > Is it mandatory for SIP servers to generate to UA 180 Ringing to inform
> > them that the called party is now ringing ?
> 
> No
> >  
> > The reason i'm asking is because I am seeing strange results using
> > different UAs.
> >  
> > Using SIP clients to call out , instead of seeing 180 Ringing , i see
> > 183 session progress even before call was picked up.
> 
> This is nothing wrong with this :)
> >  
> > On some sip client , ring back can be heard.
> good, they support early media
> > On some others , ring back cannot be heard.
> Bad,, they do not support Early media
> >  
> > Is there any reason to suspect that these UAs needs to receive 180
> > Ringing before generating any ringback ?
> In general: 
> 180 == Generate Local Ringback.
> 183 == get RTP from callee, and play it (often used for network
> announcements, calls to gSM and simular)
> 
> - Atle
> >  
> > Regards,
> > Sam
> 
> > _______________________________________________
> > Users mailing list
> > Users at openser.org
> > http://openser.org/cgi-bin/mailman/listinfo/users
> 
> 
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