[cisco-voip] Static noise on FXO ports
OConnell, Ryan
Ryan.OConnell at nexinnovations.com
Thu Jun 8 17:05:02 EDT 2006
The phones are directly connected to the powered ESM on the router. I
have ruled out internal cabling issues by directly connecting phones to
the ESM. Also IP to IP calls work fine it is only PSTN calls through the
FXO ports. Another interesting thing that I have noticed is that the
static seems to only happen as I am talking into the IP phone. If the
PSTN person is talking and I am listening I hear no static. The moment I
speak into the IP phone I hear the background static in my ear. The PSTN
person does not hear the static. If I have a call connected and do not
speak into the set it sound clean. If I breath into the set I hear
static, it is continuous as I speak or add noise to the mouth-piece.
Thank
Ryan O'Connell
Senior Consultant CCIE Voice (13382)
NexInnovations Inc.
3636 - 23rd Street N.E.
Calgary, AB. T2E 8Z5
Desk (403) 291-7293
Cell: (403) 990-1275
Fax: (403) 291-7281
Ryan.OConnell at nexinnovations.com
http://www.nexinnovations.com <http://www.nexinnovations.com/>
________________________________
From: Jim McBurnett [mailto:jim at tgasolutions.com]
Sent: June 8, 2006 2:09 PM
To: OConnell, Ryan; cisco-voip at puck.nether.net
Subject: RE: [cisco-voip] Static noise on FXO ports
, look for any resistance impacting devices-- Carbon blocks etc..
between where you plug in the phone and the CME..
is it a short run from the jack to the CME router?
Later,
Jim
________________________________
From: cisco-voip-bounces at puck.nether.net
[mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of OConnell, Ryan
Sent: Thursday, June 08, 2006 3:49 PM
To: cisco-voip at puck.nether.net
Subject: [cisco-voip] Static noise on FXO ports
Hello all,
I've been battling this issue with what was suppose to be a simple
little CME install for 10 people for a little while now and I'm at my
wits end. My customer has a 2801 router with VIC2-4FXO a single PVDM2-8
DSP and an 8 port powered Etherswitch module. I have turned vad on/off,
comfort noise on/off, I have played with input gain, output gain, and
impedance settings. I tested the pots lines with a regular analog phone
I get no noise at all. When making a call as soon as the call is
connected the static starts. Internal IP to IP phone calls are great and
calls over the WAN are great. TAC had me do a procedure where I captured
the voice to a wav file before it went through the DSP and after it went
through the DSP and the static can not be heard. I also got the TELCO in
to test the lines for any nuances and I had the customer ground the rack
the 2801 was mounted into. Lastly TAC shipped me all brand new equipment
but the problem still persists after I swapped it out.
I'm running 12.3(14T) IOS. This customer has a second site with
identical hardware and IOS and is not experiencing the problem.
It has to be the phone lines but the Telco says they are fine and since
I can plug a regular phone into the line and get no noise it is hard to
argue with them.
Thoughts?
Ryan O'Connell
Senior Consultant CCIE Voice (13382)
NexInnovations Inc.
3636 - 23rd Street N.E.
Calgary, AB. T2E 8Z5
Desk (403) 291-7293
Cell: (403) 990-1275
Fax: (403) 291-7281
Ryan.OConnell at nexinnovations.com
http://www.nexinnovations.com <http://www.nexinnovations.com/>
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