There was a real bad echo bug in the 12.4 train around 12.4(11)T and 12.4(7) or so. <br><br>The trick is replicating the problem. Sometimes you can use output gain and attenuation to reduce the difference between the outgoing voice and the echo coming back in so that the echo canceler can tell the difference between voice and echo.<br>
<br>Like mentioned, headsets will get you. So will latencies over 128ms. G.114 (?) says 150ms, but in reality you really want to be less than 150 if a PSTN gateway is involved because of this limitation.<br><br>I've got a particularly tricky bug out there that still isn't solved: CSCtb26941<br>
<br>If you do a 'show call active voice echo summary' and you see the tail jumping between 24ms and 112ms, you're hitting the bug. A reload helps, or you may try IOS in the 15.x train since some of the echo code has changed. Otherwise you can reload the router and it probably won't happen to you again unless you've got a lot of routers. This thing can take up to 2-3 years to hit some times.<br>
<br>-nick<br><br><div class="gmail_quote">On Mon, Aug 23, 2010 at 4:52 PM, Marcus Smith <span dir="ltr"><<a href="mailto:msmith@laurinburg.org">msmith@laurinburg.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div bgcolor="#ffffff">
<div><font size="2" face="Arial">The users are using handsets and these are external
calls. Also, this is what I got after using sh controllers
t1command:</font></div>
<div><font size="2" face="Arial"></font> </div>
<div><font size="2" face="Arial">2811-Gateway#sh controller t1<br>T1 0/0/0 is
up.<br> Applique type is Channelized T1<br> Cablelength is long
gain36 0db<br> No alarms detected.<br> alarm-trigger is not
set<br> Soaking time: 3, Clearance time: 10<br> AIS
State:Clear LOS State:Clear LOF State:Clear<br> Version info
Firmware: 20060707, FPGA: 13, spm_count = 0<br> Framing is ESF, Line Code
is B8ZS, Clock Source is Line.<br> CRC Threshold is 320. Reported from
firmware is 320.<br> Data in current interval (231 seconds
elapsed):<br> 0 Line Code Violations, 0 Path Code
Violations<br> 0 Slip Secs, 0 Fr Loss Secs, 0 Line Err
Secs, 0 Degraded Mins<br> 0 Errored Secs, 0 Bursty Err
Secs, 0 Severely Err Secs, 0 Unavail Secs<br> Total Data (last 24
hours)<br> 0 Line Code Violations, 0 Path Code
Violations,<br> 0 Slip Secs, 0 Fr Loss Secs, 0 Line Err
Secs, 0 Degraded Mins,<br> 0 Errored Secs, 0 Bursty Err
Secs, 0 Severely Err Secs, 0 Unavail Secs</font></div><div class="im">
<div><br>Marcus Smith<br>IT Manager/Dir<br>City of
Laurinburg<br>Direct (910) 291-2580 <br>Mobile (910)
280-2781 <br><a href="mailto:msmith@laurinburg.org" target="_blank">msmith@laurinburg.org</a><br></div>
</div><blockquote dir="ltr" style="padding-right: 0px; padding-left: 5px; margin-left: 5px; border-left: 2px solid rgb(0, 0, 0); margin-right: 0px;"><div class="im">
<div style="font: 10pt arial;">----- Original Message ----- </div>
<div style="background: none repeat scroll 0% 0% rgb(228, 228, 228); font: 10pt arial;"><b>From:</b>
<a title="msmith@laurinburg.org" href="mailto:msmith@laurinburg.org" target="_blank">Marcus
Smith</a> </div>
<div style="font: 10pt arial;"><b>To:</b> <a title="cisco-voip@puck.nether.net" href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a> </div>
<div style="font: 10pt arial;"><b>Sent:</b> Monday, August 23, 2010 3:45
PM</div>
</div><div class="im"><div style="font: 10pt arial;"><b>Subject:</b> Phone echo</div>
<div><br></div>
<div><font size="2" face="Arial">Here is a little problem for all. Over the
last week or two, several users have stated that they are experiencing
echoing( hearing their voices) when they are on the phone. When I
checked these extension I am hearing any echoing. The users have been
advised to verify whether or not these calls are from land line or cell
phone. They reported back both. What other in-depth
troubleshooting method can I apply</font></div>
<div><font size="2" face="Arial"><br>Marcus Smith<br>IT Manager/Dir<br>City of
Laurinburg<br>Direct (910) 291-2580 <br>Mobile (910)
280-2781 <br><a href="mailto:msmith@laurinburg.org" target="_blank">msmith@laurinburg.org</a><br></font></div></div></blockquote></div>
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<br></blockquote></div><br>