[asterisk-users] odd sound between SIP & IAX clients

[Tim Panton]

On 26 Jul 2006, at 03:04, Joseph Love wrote:

> The issue which occurs is that the audio from the SIP client to the  
> IAX client will spend most of it's time sounded very robotic, and  
> garbled.  It is possible, although very difficult to understand  
> someone who is on the SIP phone.
>
> I have asterisk 1.2.10 configured with realtime with both IAX and  
> SIP clients.
> The SIP clients include a Grandstream gxp2000 hard phone, and  
> Counterpath's X-Lite 3 (for windows) softphone.
> The IAX clients tested include idefisk (both windows & mac),  
> JakenIAX, and LoudHush.
> GSM is the preferred codec of both IAX & SIP clients, and is indeed  
> the codec being used in all tests.
>
> Audio from the IAX to the SIP client does not experience any  
> issues.  SIP to SIP (and presumably, although untested, IAX to IAX)  
> communication does not experience any issues.
>
> We also have a T1 card through which many calls have been placed,  
> both from the IAX and SIP phones, without any audio issues  
> occurring, in either case.
>
> If it weren't for that there have been multiple clients tested to  
> verify this robotic sound, I would cough it up to it being a  
> incompatability between the particular clients, but this occurs on  
> all SIP-IAX communication that has been tried.
>
> I'm running out of options as SIP-IAX intercommunication is kinda  
> expected (and necessary for me), and out of good softphones for the  
> mac, as most of the mac-compatible softphones are IAX2-based.
>
> Please let me know what additional information is needed to help me  
> debug this problem.

We have had reports like this, and it is looking like the iax  
jitterbuffer is the culprit.
Try adding jitterbuffer=no to the general section of iax.conf and see  
if that helps.


Tim Panton

www.mexuar.com