Call from PSTN E1 ISDN PRI to Cisco 7920 crackling noise

Unanswered Question
May 14th, 2007

Hello everybody.

When I received a call from PSTN through PSTN>H323 GATEWAY>CCM>Access Point>Ciso 7920. I hear a crackling noise on the phone but if I make a call backwards from Cisco 7920 to PSTN it works fine.

The other phones like Cisco 7912 and Cisco 7960 work fine in both directions from PSTN and to PSTN.



I have this problem too.
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Paolo Bevilacqua Mon, 05/14/2007 - 08:31


the fact that depedning on the direction of the call the problem occurs, is a bit strange. Which FW do you have on the 7920 ? Mon, 05/14/2007 - 10:34

Hi Bevilacqua

The firware on all the Cisco 7920 is 7920.4.0-03-01.

According to the TAC informacion about crackling noise is a battery problem I have tried 5 differents phone and I get the same problem.


Paolo Bevilacqua Mon, 05/14/2007 - 11:18

Thanks for letting us know, this is bad, as cisco admits the problem is with the phone, you should be able to send them back and either they give you ones that have no problem, or credit for another purchase. Mon, 05/14/2007 - 12:53

Hello Bevilacqua.

Do you have the information where cisco admits the problem with the phone??



Paolo Bevilacqua Mon, 05/14/2007 - 12:56

I was relying on what you said, I guess an email from tac or case details are sufficient the bring up the matter with the sales representative.


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