No ring back tone on dialup E1 modem users

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May 12th, 2009
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I have a 2821 with nmc1e1pri and pvdm2dm configured as RAS. Contrller status is as follows

Applique type is Channelized E1 - unbalanced

No alarms detected.

alarm-trigger is not set

Framing is NO-CRC4, Line Code is HDB3, Clock Source is Line.

Module type is Channelized E1/T1 PRI

Version info Firmware: 0000001D, FPGA: C

Hardware revision is 0.0 , Software revision is 29

Protocol revision is 1

number of CLI resets is 0

receive remote alarm : 3,

transmit remote alarm : 0,

receive AIS alarm : 0,

transmit AIS alarm : 0,

loss of frame : 0,

loss of signal : 0,

Loopback test : 0,

transmit AIS in TS 16 : 0,

receive LOMF alarm : 0,

transmit LOMF alarm : 0,

MIB data updated every 10 seconds.

Data in current interval (522 seconds elapsed):

0 Line Code Violations, 0 Path Code Violations

0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

the only thing i notice is that every time I configure "network-clock-select 1 e1 2/0" the interface goes down with remote alarm. Could this be the problem on the telco side or isthere something wrong with the config/hardware?

<strong>Attachment Keywords : </strong>

1) run.txt - running/show version

2) version.txt

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paolo bevilacqua Wed, 05/13/2009 - 07:01
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Since you have no errors and no slips, do not worry entering the command and leave things are they are.

Altough, it should not happen.

dehghan Thu, 05/14/2009 - 01:07
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what do you think might be the cause of the no ringback tone problem. After the user dials it gets to a point where I recieve this:


and eventually the line drops because of timeout.


paolo bevilacqua Thu, 05/14/2009 - 13:30
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At that point the router has answered the call and you should hear modulation tones.

dehghan Sat, 05/16/2009 - 20:56
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I have checked again and still nothing. any ideas? I am nt sure but I think this is some thing to do with the telco's side but they do not accept it.

By the way the the telco gives us these E1 lines through an STM1 channelized link. there is a huawei channelizer in front of my router with the STM1 in and E1 out scenario.

Any help would be much apritiated.

paolo bevilacqua Sat, 05/16/2009 - 22:31
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You may want to contact the TAC on this. You must hear modem answer tones or something is seriously wrong.


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