asterisk users - Nov 2008 - echo cancellation for sip phones

Dear,
the sip phones that registered, in to the asterisk 1.4.x have the echo in their
callings to pstn.
how this echo can be canceled?
Best





      
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Pezhman Lali wrote:
> Dear,
> the sip phones that registered, in to the asterisk 1.4.x have the echo 
> in their callings to pstn.
> how this echo can be canceled?
Hmmmm - you don't give much to go on...

What is the connection to the PSTN (i.e. what kind of card, interface 
etc...)

The echo is almost certainly coming from that area rather than the SIP 
phones themselves.

If you have an analogue PSTN card without h/w echo cancellation, I would 
suggest trying the OSLEC echo canceller. This is[was?] not installed by 
default with the zaptel drivers.

HTH

Alan