[Asterisk-Users] SIP and ECHO

[Fredrik Hedberg]

What have you specified as rx and txgain?

Simon McAuliffe wrote:

>I've been having the same problem too, except for me it only happens
>occasionnally.
>
>I'm not 100% sure of this, but it seems that for very local calls (eg across
>the city) I never get echo.  For calls that go longer distance (say 500km or
>more), or through some closer call centres, I'm getting the echo.  I don't
>get the echo on an analogue POTS connection to the same places (it is
>clearly only happening on our asterisk system).
>
>This might indicate some link between echo cancellation and delayed audio,
>but if so, its sensitive to very small delays.
>
>The echo can only be heard at our end, there is no trace of it at the other
>end.
>
>I'm using ATAs doing SIP to Asterisk and through a PRI connection to a
>Telco.  Echo cancellation is turned on and showing as activated on the Zap
>channels.  Echo cancellation is also enabled on the ATAs.
>
>----- Original Message ----- 
>From: "Brian J. Schrock" <brians at anistonetech.com>
>To: <asterisk-users at lists.digium.com>
>Sent: Friday, August 29, 2003 3:16 AM
>Subject: [Asterisk-Users] SIP and ECHO
>
>
>  
>
>>Hello,
>>
>>I have read the information on echo and SIP in the FAQ and I have
>>scoured the mailing list for possible solutions, but as yet I have not
>>been able to get rid of this echo.
>>
>>I have a Sip phone, Digium 4 Port FXS, and 3 Digium FXO cards installed
>>into an asterisk server. If I call between the Sip Phone
>>(Budgettone-100) and the 4 FXS ports everything sounds great. If I call
>>out to the PSTN through the FXO cards I get horrible echo, I have even
>>been able when talking loud enough to get a horrible feedback loop
>>going. I have tried 4 different echo cancellers in the Makefile for the
>>Zap drivers and nonoe of them changed the situation.
>>
>>I have echocancel = (Any where from 1 - 256, I have tried alot of
>>different values), and I have echocanelwhenbridged = yes.I only hear the
>>echo start when the call gets bridged onto the outgoing PSTN lines.
>>
>>Is there anything I can do?
>>
>>Brian J. Schrock
>>
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>>Asterisk-Users at lists.digium.com
>>http://lists.digium.com/mailman/listinfo/asterisk-users
>>
>>    
>>
>
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>
>  
>


-- 
Fredrik Hedberg		       

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