<HTML dir=ltr><HEAD><TITLE>Re: [cisco-voip] Echo on IP Phones through PRI</TITLE>
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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>Increasing the output attenuation maybe helpful try to have a value that gives u an acceptable level of echo. </FONT></DIV>
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<DIV class=ecsection1 style="MARGIN: auto 0in"><SPAN style="FONT-SIZE: 10pt; COLOR: #003366; FONT-FAMILY: Tahoma">Thanks and Best Regards<BR><B><BR>Ahmed A. Elnagar<BR></B>Network Field Engineer</SPAN></DIV>
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<DIV class=ecsection1 style="MARGIN: auto 0in"><SPAN lang=ES style="FONT-SIZE: 10pt; COLOR: #003366; FONT-FAMILY: Tahoma; mso-ansi-language: ES">Advanced Computer Technology (ACT)<BR>16 Fawzy Ramah St.Off Shehab St.Mohandessin, Giza, Egypt <BR>Postal Code:12411 Cairo Egypt<BR></SPAN><SPAN style="FONT-SIZE: 6pt; COLOR: #003366; FONT-FAMILY: Tahoma"><BR></SPAN><SPAN class=ecspelle><B><SPAN lang=ES style="FONT-SIZE: 10pt; COLOR: #003366; FONT-FAMILY: Tahoma; mso-ansi-language: ES">Mob</SPAN></B></SPAN><B><SPAN style="FONT-SIZE: 10pt; COLOR: #003366; FONT-FAMILY: Tahoma">:</SPAN></B><SPAN style="FONT-SIZE: 10pt; COLOR: #003366; FONT-FAMILY: Tahoma"> +2010-2833868</SPAN><SPAN style="FONT-SIZE: 10pt; COLOR: black; FONT-FAMILY: Tahoma"><BR></SPAN><B><SPAN lang=ES style="FONT-SIZE: 10pt; COLOR: #003366; FONT-FAMILY: Tahoma; mso-ansi-language: ES">Website</SPAN></B><B><SPAN style="FONT-SIZE: 10pt; COLOR: black; FONT-FAMILY: Tahoma">: </SPAN></B><SPAN lang=ES style="FONT-SIZE: 10pt; COLOR: #003366; FONT-FAMILY: Tahoma; mso-ansi-language: ES">www.act-eg.com<BR><B>E-mail</B></SPAN><B><SPAN style="FONT-SIZE: 10pt; COLOR: #004600; FONT-FAMILY: Tahoma">: </SPAN></B><SPAN lang=ES style="FONT-SIZE: 10pt; COLOR: #003366; FONT-FAMILY: Tahoma; mso-ansi-language: ES"><A href="mailto:aelnagar@act-eg.com">aelnagar@act-eg.com</A></SPAN></DIV></FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>From:</B> cisco-voip-bounces@puck.nether.net on behalf of Chris D'amore<BR><B>Sent:</B> Wed 18-Apr-07 3:21 PM<BR><B>To:</B> Matthew Melbourne; cisco-voip@puck.nether.net<BR><B>Subject:</B> Re: [cisco-voip] Echo on IP Phones through PRI<BR></FONT><BR></DIV>
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<P><FONT size=2>Are you seeing slip errors on any of the PRI's?<BR><BR><BR>-----Original Message-----<BR>From: cisco-voip-bounces@puck.nether.net<BR>[<A href="mailto:cisco-voip-bounces@puck.nether.net">mailto:cisco-voip-bounces@puck.nether.net</A>] On Behalf Of Matthew<BR>Melbourne<BR>Sent: Wednesday, April 18, 2007 7:50 AM<BR>To: cisco-voip@puck.nether.net<BR>Subject: [cisco-voip] Echo on IP Phones through PRI<BR><BR>We are getting sporadic issues from users on IP phones who are hearing<BR>echo on external calls. From this document is would suggest that echo<BR>on IP Phones is caused by hybrid echo and not any local acoustic echo.<BR><BR><A href="http://www.cisco.com/warp/public/788/voice-qos/echo_ipphone_gateway.html">http://www.cisco.com/warp/public/788/voice-qos/echo_ipphone_gateway.html</A><BR><BR>The MGCP-controlled voice gateways are all running 12.3(14)T7 with DSP<BR>firmware 4.4.708. In CallManager (4.1(3)SR2), echo cancellation is on<BR>for each port, with a "default" echo cancellation coverage of 64ms.<BR>Input gain and output attenuation are set to 0dB.<BR><BR>I have seen suggestions to include the "echo-cancel erl worst-case 3"<BR>command on the voice ports. Can this help in situations of occasional<BR>echo?<BR><BR>Are there any other parameters changes which could help? Could it be a<BR>code/DSP firmware issue? I haven't found a specific echo-related bug<BR>relating to this particular IOS and its embedded DSP firmware.<BR><BR>On occasions, the start of the call is fine but echo comes and goes<BR>during the call.<BR><BR>Is there a quick way of finding out which voice gateway a call is<BR>terminated on (we have 8, and all could be used in a round-robin<BR>fashion for outbound calls).<BR><BR>Cheers,<BR><BR>Matt<BR><BR>--<BR>Matthew Melbourne<BR>_______________________________________________<BR>cisco-voip mailing list<BR>cisco-voip@puck.nether.net<BR><A href="https://puck.nether.net/mailman/listinfo/cisco-voip">https://puck.nether.net/mailman/listinfo/cisco-voip</A><BR>NOTICE: This electronic mail message and any files transmitted with it are intended exclusively<BR>for the individual or entity to which it is addressed. The message, together with any attachment, may contain confidential and/or privileged<BR>information. Any unauthorized review, use, printing, saving, copying, disclosure<BR>or distribution is strictly prohibited. If you have received this message in error, please immediately<BR>advise the sender by reply email and delete all copies.<BR><BR>_______________________________________________<BR>cisco-voip mailing list<BR>cisco-voip@puck.nether.net<BR><A href="https://puck.nether.net/mailman/listinfo/cisco-voip">https://puck.nether.net/mailman/listinfo/cisco-voip</A><BR></FONT></P></DIV></BODY></HTML>