No answerback tone on digital modem

Unanswered Question
Oct 18th, 2009


I have a 2821 router with DSP and digital modem module installed. with vwic and e1 nm module. Every thing works ok when I have my E1 lines configured as Voice lines but I cant hear any modem answerback tone from the digital modems when the E1 line is configured for incoming modem. I have checked the E1 layer two and three status and every thing is ok. Connection is made only to be timed out after a whilesince there is no modem music. I thought there might be something wrong with the chasis so I tested the E1 line with a 2811 router, but the same thing happened.

The lines come in through fiber from the telco and there is a Huawei channelizer in between my router and the telco. there are other E1 lines from the channelizer that go to the local PBX system and they are working perfectly.

Any ideas?

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dehghan Mon, 10/19/2009 - 10:25

I was using the VWIC card with PVDM for testing the E1 functionalit which was ok. I am using NM-CE1T1 PRI nework module for the digital modems witch has the problem.

I will get he configs and post them here.

Thank you in advance

dehghan Tue, 10/20/2009 - 09:26

I have attached the running config/show version,debug ISDNQ931,debug modem csm.

Any help would be much appreciated

Paolo Bevilacqua Tue, 10/20/2009 - 10:57

Recommend you contact the TAC about this.

Someone else reported the same problem, but never updated on the cause or solution.

dehghan Tue, 10/20/2009 - 11:04

The strange thing is as I said before, I have tested the digital modemand also the NM in another site and they worked fine.

I have thought perhaps thee was something else wrong with the chasis and I tested another chasis and yet no luck. I have no idea about this one. the hardware should work since they have worked someplace else. The telco is oksince every thing is coming in ok and we have Voice on this router. :|

Seems no options left but to contact TAC.


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