[asterisk-users] Per DID Codec Negotiation

[Damien Gabrielson]

Hi Everyone,

 From my research I believe I am asking the impossible but perhaps I am 
missing something. Any help would be greatly appreciated.

I receive many DIDs from the same SIP provider coming from the same IP. 
I have a peer setup in sip.conf for this provider and this is where the 
codec negotiation happens. The problem comes in when I have to send a 
given SIP call to a device that only accepts g729. I have to accept ulaw 
from the provider so that fax will work and transcoding to g729 is not a 
good option because it takes up CPU resources and costs extra money. 
Since the provider supports g729, I would like to receive calls for some 
DIDs as g729 and the rest as ulaw. Is there any possible way to have 
this kind of configuration when all the DIDs come from the same IP and 
there is no SIP registration? As a side note, if I accepted the calls 
through IAX from the provider and sent them out as SIP, would this help?

Thanks,
Damien Gabrielson