[asterisk-users] echo cancellation for sip phones

Alan Lord alanslists at gmail.com
Thu Nov 20 02:31:59 CST 2008

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 

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.



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