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<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>Thanks Wes. </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>Well I've expanded echo cancellation on
the gateway. (PRI with MGCP, CCM6.1) So your first paragraph is
saying that most likely echo is generated too "far away" (too much delay) from
my GW to cancel the tail end echo coming into our system--even with my expanded
echo cancellation in place. So only the telco might have a chance of
cancelling that echo "closer to" the echo source.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>As I understand it, I might also change phone loads (hence
my question about 7911s). And I might try some gain/attenuation settings
on the GW as well--or so I've read.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>So in a VOIP system that has echo, I
can:</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>1. Bug the telco</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>2. Expand echo cancellation on the GW</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>3. Attenuation/gain statements on GW</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>4. Change phone load</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>At least so far that's all I've found I can tinker
with. Is that about it?</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>Anyone use attenuation or gain statements on their
GWs? I know the statements, but I don't know what their function really
is, whether I would use one or the other or both, or what I would set them
to.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>Thanks</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2>jeff</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=263310719-31082010><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> Wes Sisk [mailto:wsisk@cisco.com]
<BR><B>Sent:</B> Tuesday, August 31, 2010 2:00 PM<BR><B>To:</B> Jeff
Ruttman<BR><B>Cc:</B> Cisco VOIP<BR><B>Subject:</B> Re: [cisco-voip] Echo
Cancellation and 7911 Phone Loads<BR></FONT><BR></DIV>
<DIV></DIV>Talker echo is usually caused by echo at far end tail circuit.
With VOIP that delay is going to be too long for the talker's phone to
cancel. It will have to canceled closer to the source of the
echo.<BR><BR>Otherwise, AFAIK, all cisco phones (except soft) have local ecan to
prevent speaker audio from going back into mic.<BR><BR><BR><A
class=moz-txt-link-freetext
href="http://www.voiptroubleshooter.com/problems/echo.html">http://www.voiptroubleshooter.com/problems/echo.html</A><BR><A
class=moz-txt-link-freetext
href="http://www.cisco.com/en/US/partner/docs/ios/solutions_docs/voip_solutions/EA_ISD.html">http://www.cisco.com/en/US/partner/docs/ios/solutions_docs/voip_solutions/EA_ISD.html</A><BR><A
class=moz-txt-link-freetext
href="http://www.cisco.com/en/US/partner/tech/tk652/tk698/technologies_tech_note09186a0080149a1f.shtml">http://www.cisco.com/en/US/partner/tech/tk652/tk698/technologies_tech_note09186a0080149a1f.shtml</A><BR><BR>/Wes<BR><BR>Jeff
Ruttman wrote:
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<DIV><SPAN class=997510914-31082010><FONT face=Arial
size=2>Greetings,</FONT></SPAN></DIV>
<DIV><SPAN class=997510914-31082010></SPAN> </DIV>
<DIV><SPAN class=997510914-31082010><FONT face=Arial size=2>Can someone
confirm or deny my memory? I recall reading that phone loads for 7911
phones don't really contain echo cancellation programming. In looking
now, I can't find much info on echo cancellation in relation to different
phone models/loads in general and nothing on 7911s.</FONT></SPAN></DIV>
<DIV><SPAN class=997510914-31082010></SPAN> </DIV>
<DIV><SPAN class=997510914-31082010><FONT face=Arial size=2>We have an office
mostly full of 7911s recently complaining of talker echo. There are
loads out on cisco.com newer than the ones we're using, and
while it's not hard to change phone loads, it would be pointless to do it if
the phone loads don't contain echo cancellation.</FONT></SPAN></DIV>
<DIV><SPAN class=997510914-31082010></SPAN> </DIV>
<DIV><SPAN class=997510914-31082010><FONT face=Arial size=2>Any
insight?</FONT></SPAN></DIV>
<DIV><SPAN class=997510914-31082010></SPAN> </DIV>
<DIV><SPAN class=997510914-31082010><FONT face=Arial
size=2>Thanks</FONT></SPAN></DIV>
<DIV><SPAN class=997510914-31082010><FONT face=Arial
size=2>jeff</FONT></SPAN></DIV><PRE wrap=""><HR width="90%" SIZE=4>
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