[Asterisk-Users] Echo Cancelling VoIP traffic

[Martin Joseph]

On Jun 17, 2006, at 9:11 AM, Rich Adamson wrote:

>> I know that the zaptel modules have echo cancellation, but is this 
>> possible to do this on VoIP <-> VoIP traffic as well? I'm toying with 
>> a SIP gateway which has apparently a terrible call quality and would 
>> like to know if there is any way asterisk can help with this.
>
> I believe the current Trunk code does include jitterbuffering for sip, 
> etc. But, the echo cancellation exists for zap only.
>
> Some of the sip gateways on the market do an excellent job with EC. 
> The Mediatrix 1204 as one example is very good, while less expensive 
> boxes (such as the spa3000, ht488) have significant limitations.
I am using the Wellgate 3701a, which is a 1 port FXO, one port FXS, and 
although it was a major pain to setup, it did solve the echo issue I 
had with my PSTN line. The recent firmware update for it also seems to 
have helped make it better in some ways.

The only remaining issue is that is takes a number of seconds to train 
at the beginning of the call.  This is ok for me, but seem to throw off 
other users, who are taken aback by the echo.  I am still thinking of 
some way to help this training along?  Any ideas?

Marty