[Asterisk-Users] Lots of Echo with SIP -> Asterisk -> PSTN

[James Freire]

Hi all.
I am having this echo problem on my SIP phones when I am making a call from SIP to a PSTN line through asterisk. The echo goes away eventually after a few seconds when the call starts but it is very aparent during the start of the call. I do have echo cancellation turned on in asterisk as well as on the sip device. This is an ATA and not a SIP phone like a grandstream. 

I am running asterisk on a PII 350mhz machine and I am not sure if that has anyhing to do with the lack of performance in echo cancelation. I have 4 Digium FXO and 4 FXS ports in this machine.
I know it does take a good ammount of CPU power to do echo cancellation. Later today I am getting a faster machine but I just wanted to see if there were any settings or tuning I can do in the compilation of asterisk to get it to perform better.

Thanks a lot,

James