<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">thanks for your writing<br>the network is like behind:<br><br>Sip phone(caller)--->SER---->Asterisk----> world telephone carrier--->pstn-->callee<br><br>the carriers and their routers are not accessible for us , the callees have not any echo in their callings but the caller(sip phones) has the echo.<br>there isn't any telephone cards on our servers(SER and Asterisk) , all of calls are come from or going out , on internet connections<br><br><br>--- On <b>Thu, 11/20/08, Alan Lord <i><alanslists@gmail.com></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;">From: Alan Lord <alanslists@gmail.com><br>Subject: Re: [asterisk-users] echo cancellation for sip phones<br>To: asterisk-users@lists.digium.com<br>Date: Thursday, November 20, 2008, 12:01 PM<br><br><pre>Pezhman Lali
wrote:<br>> Dear,<br>> the sip phones that registered, in to the asterisk 1.4.x have the echo <br>> in their callings to pstn.<br>> how this echo can be canceled?<br><br>Hmmmm - you don't give much to go on...<br><br>What is the connection to the PSTN (i.e. what kind of card, interface <br>etc...)<br><br>The echo is almost certainly coming from that area rather than the SIP <br>phones themselves.<br><br>If you have an analogue PSTN card without h/w echo cancellation, I would <br>suggest trying the OSLEC echo canceller. This is[was?] not installed by <br>default with the zaptel drivers.<br><br>HTH<br><br>Alan<br><br><br>_______________________________________________<br>-- Bandwidth and Colocation Provided by http://www.api-digital.com --<br><br>asterisk-users mailing list<br>To UNSUBSCRIBE or update options visit:<br> http://lists.digium.com/mailman/listinfo/asterisk-users<br></pre></blockquote></td></tr></table><br>