[Asterisk-Users] SIP to IAX - forcing codec pass thru

[Thomas Kenyon]

Peter Gradwell wrote:
> 
> mmm, but as you've seen, some customers like using multiple codecs. The 
> cisco kit is able to support a raft of options - and it does transcoding 
> very nicely - so the optimum solution is to have the cisco + customer's 
> asterisk agree on the same codec, and then have our asterisk server (in 
> the middle) do as little as possible.
> 
As an example, I'm one such customer who likes to send voice calls to 
them as G.729 and fax calls as G.711a.

IIRC a standard has been defined for end-to-end codec renegotiation, but 
this hasn't been implemented into asterisk (opr probably anything else) yet.