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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>FYI – A bug was discovered in 15.1(2)T1. This is likely unrelated to the tone tests failing however describe the analog quality exactly.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=EN-US>CSCth60636</span></b><span lang=EN-US> - PVDM3: clipping and choppy audio during double talk</span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";mso-fareast-language:EN-CA'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";mso-fareast-language:EN-CA'> cisco-voip-bounces@puck.nether.net [mailto:cisco-voip-bounces@puck.nether.net] <b>On Behalf Of </b>Ryan Schwab<br><b>Sent:</b> March-02-11 12:50 PM<br><b>To:</b> cisco-voip@puck.nether.net<br><b>Subject:</b> [cisco-voip] Analog FXO PSTN audio quality complaints<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have users complaining of degraded PSTN audio quality over FXO ports on a 2911 h323 gateway. The problem is described as “audio cutting in and out when both people talk simultaneously.”<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>My initial suspicion is certainly a PSTN cabling issue so I ran a few THL tone sweep tests. When ran, I get the output below:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>JWESRT01(config-dial-peer)#do test voice port 0/0/3 thl-sweep verbose<o:p></o:p></p><p class=MsoNormal>Original impedance 600r. Input signal level=-41dBm<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>testing 600r...... Input Signal level=-41dBm<o:p></o:p></p><p class=MsoNormal>Freq (hz), ERL (dB), TX Power (dBm), RX Power (dBm)<o:p></o:p></p><p class=MsoNormal>354 5 -6 -11<o:p></o:p></p><p class=MsoNormal>554 5 -6 -11<o:p></o:p></p><p class=MsoNormal>754 5 -6 -11<o:p></o:p></p><p class=MsoNormal>954 6 -6 -12<o:p></o:p></p><p class=MsoNormal>1154 5 -6 -11<o:p></o:p></p><p class=MsoNormal>1354 5 -6 -11<o:p></o:p></p><p class=MsoNormal>1554 5 -6 -11<o:p></o:p></p><p class=MsoNormal>1754 5 -6 -11<o:p></o:p></p><p class=MsoNormal>1954 5 -6 -11<o:p></o:p></p><p class=MsoNormal>2154 4 -6 -10<o:p></o:p></p><p class=MsoNormal>2354 4 -6 -10<o:p></o:p></p><p class=MsoNormal>2554 4 -6 -10<o:p></o:p></p><p class=MsoNormal>2754 4 -6 -10<o:p></o:p></p><p class=MsoNormal>2954 4 -6 -10<o:p></o:p></p><p class=MsoNormal>3154 4 -6 -10<o:p></o:p></p><p class=MsoNormal>3354 3 -6 -9<o:p></o:p></p><p class=MsoNormal>testing complete for 600r. ERL=5<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>testing 900r...... Input Signal level=-43dBm<o:p></o:p></p><p class=MsoNormal>Freq (hz), ERL (dB), TX Power (dBm), RX Power (dBm)<o:p></o:p></p><p class=MsoNormal>354 9 -6 -15<o:p></o:p></p><p class=MsoNormal>554 9 -6 -15<o:p></o:p></p><p class=MsoNormal>754 8 -6 -14<o:p></o:p></p><p class=MsoNormal>954 8 -6 -14<o:p></o:p></p><p class=MsoNormal>1154 7 -6 -13<o:p></o:p></p><p class=MsoNormal>1354 7 -6 -13<o:p></o:p></p><p class=MsoNormal>1554 6 -6 -12<o:p></o:p></p><p class=MsoNormal>1754 5 -6 -11<o:p></o:p></p><p class=MsoNormal>1954 5 -6 -11<o:p></o:p></p><p class=MsoNormal>2154 4 -6 -10<o:p></o:p></p><p class=MsoNormal>2354 4 -6 -10<o:p></o:p></p><p class=MsoNormal>2554 3 -6 -9<o:p></o:p></p><p class=MsoNormal>2754 3 -6 -9<o:p></o:p></p><p class=MsoNormal>2954 3 -6 -9<o:p></o:p></p><p class=MsoNormal>3154 3 -6 -9<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>ERL very low. set_impedance to 900r failed !!!.<o:p></o:p></b></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Has anyone ran into this while performing analog tests? Does the fact that it fails almost certainly point to an issue past the FXO port on the router?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks for the advice!<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>-Ryan<o:p></o:p></p></div></body></html>