[asterisk-users] Can't get G.729 to work...

[Tim Nelson]

----- "Ben Schorr" <bens at rolandschorr.com> wrote:
> I thought I already did that - which is how they now get some (but
> not
> yet all) of their calls on G.729.  <scratching head>
> 

<VERY SIMPLIFIED VIEW>
Allowing G.729 in your configurations (disallow=all, allow=g729) enables those endpoints to use that codec *THROUGH* the Asterisk system to other endpoints who support that codec. The PRI coming into the system can only use a single codec which is ulaw in your case (some locations use alaw). So, since both "endpoints" cannot agree on g729, they fall back to a codec they both know, ulaw.

Now, if you had G.729 codec licensed, Asterisk would simply take the ulaw audio from the PRI, transcode it to G.729, and pass it to your phone allowing the phone to operate in G.729 for these calls also.
</VERY SIMPLIFIED VIEW>

The actual underlying processes that determine how all of this happens is much more complex, specifically the SDP/SIP negotiations that occur.

Tim Nelson
Systems/Network Support
Rockbochs Inc.
(218)727-4332 x105