Not able to dial isdn number from MXP endpoint

[nikhil.kmr]

Dear Team,

We have an MXP edge 95 with ISDN BRI Line connection, Here when we connect the call after 5-10 minutes the call gets disconnected.

Currupted Data Recieved message comes.

and also on diagonostic page during the call, Frame Loss Total & Capablities Set Total both decreases and results in disconnection of the call.

But when we connect the same lines to polycom endpoint, The frames dropes but the call doesnot get disconnected.

Kindly Suggest some plan of action.

Regards

Nikhil

[Tomonori Taniguchi]

I’d suggest to take isdn trace on MXP Endpoint and monitor how often you see “!”.

This indicate how often Endpoint experience bit error on ISDN line.

Also should look for “FAW1 loss” in log which indicating lost the synch for the incoming data.

If you find “A1recover” right after “FAW1 loss” indication which is fine, otherwise Codec may restart bonding channel negotiation. (A1recover indicating Codec lost the synch but has recovered).

If you see many “!” or sync lost indication in isdn trace, I suggest to change BRI connection to other BRI port (i.e. move BRI line from port 1 to port 4).

If still have same result, should contact your local ISP and request to check ISDN connection quality.

[nikhil.kmr]

Hi Tomo,

Thanks For the reply, can you suggest how can we take ISDN trace on MXP endpoint ?

Regards

Nikhil

[Tomonori Taniguchi]

Enable and disable ISDN trace on MXP Endpoint use API command.

To start capturing ISDN trace, Access MXP Endpoint by using telnet (or from console) then execute “isdntrace on” command.

All trace outcome will print out on telnet session.

To stop capturing ISDN trace, execute “isdntrace off” command.

I strongly suggest to enable session logging (log the outcome to external file) to capture all outcome on telnet session otherwise you may lose some of early outcome due to buffer size.

[nikhil.kmr]

Hi Tomo,

We have tried the ISDN Trace but didn’t find any FAW1 loss or ! in the logs.

There was a message loss of carrier in the command screen when the call was discoonected. So is this because of service provider issue.??

I have attached the logs on your mail.

Thanks

Nikhil

[Tomonori Taniguchi]

Ops, sorry you should take isdntrace and syslog in same time.

• Enable logging on terminal application
• Execute “isdntrace on” and “syslog 3” command
• Run test call
• Execute “isdntrace off” and “syslog off” command

The isdntrace log you send me didn’t contain any useful information other than call disconnection initiated from local MXP Endpoint.

[Saurabh Gupta]

Hi Nikhil,

From my past experience on working with Endpoints, it seems most likely to be the ISDN line issue .

Because as you mentioned, the frames drop even on the polycom EP also, however the call doesnt drops. This is because different vendors have different hardware which might not lead to call disconnection.

So, I would suggest you to check ISDN lines with another Cisco EP and if the result is same , then please take it up with your ISP.

Thanks,

Saurabh