<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2800.1528" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face="Courier New" size=2>Hello everybody,</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>I am sorry to bring this up again if this
kind of echo issue has ever discussed.</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>Phone2 in below call path experiences quite
annoying echo:</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>Phone1 --> FXS (TDM400P) --> Asterisk
--> SIP GW --> PSTN --> Phone2</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>It is annoying as on phone2, we can hear
the whole words we say with the level of maybe 25% of the original sound. I can
reduce the echo to maximum with the following settings for my FXS port on
zapata.conf:</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New"
size=2>rxgain=-8.0<BR>txgain=2.0<BR>echocancel=256<BR>echotraining=500</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>But it is still not entirely
eliminated as we still sometimes hear the last syllables, with the level
of maybe 5% of the original sound.</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>What I did was just playing around with the
values of those parameters, use ztmonitor to have the FXS rx/tx
signal visualised and use only my ears to check it. I think my ears are
fine :), as I do this because my friends complain about the echo they
hear.</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>Does anybody know a better method
to find the best value for those parameters?</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>There is no echo on phone2 when
I use softphone like this:</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>
<DIV><FONT face="Courier New" size=2>PC(X-Lite) --> Asterisk --> SIP GW
--> PSTN --> Phone2</FONT></DIV></FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>The following is the version of asterisk I
am using:</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>CLI> show version</FONT></DIV>
<DIV><FONT face="Courier New" size=2>Asterisk SVN-branch-1.2-r7999 built by root
@ atvie-asterisk on a i686 running Linux on 2006-01-13 06:15:02 UTC</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>And I set the echo canceller in zconfig.h
to ECHO_CAN_MG2.</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>Cheers,</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>Anto</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV></BODY></HTML>