atcomsystems.ca/forum Forums TDM Business Telephone Systems Nortel Telephones & Systems MICS 4.1 :: Customer Reports Clicking & Loud Static

Any feedback on relevant troubleshooting techniques would be much appreciated.

My customer has a MICS 4.1 with PRI, using XO Communications as PRI provider. They recently reported experiencing intermittent clicking and loud choppy static on telephone calls, and they say they've had it for "quite some time".

They have not been able to narrow it down to any particular stations, or inbound vs. outbound calls, etc. and so I suggested that they contact XO and have them do a test on the PRI circuit.

XO reports the following: "the lines tested clean all the way to the Network Interface Unit. We ran a quasi test and the customers' CSU was returning errors, specifically 62 pattern slips and 1 CRC error, but no frame or bit errors."

Any thoughts on how I should be troubleshooting this from our side? I appreciate anyone's assistance as I'm pretty new to testing these types of circuits...

This can still be a bad NIU card or possibly a bad extended demarc - You will need to go out there and give XO a hard loop at the extended demarc and see if they are still getting errors if so make sure the extended demarc is clean. This would be my first step.

I had this issue about a year ago. Site had 2 pri's. Sprint and Bell provided. The problem was always on Bell's pri. The Bell CO tester I had finally retermed his end and the problem cleared up. Clicking and static on a pri is usually caused by poor terminations somewhere along the route.

Thanks Mark. Could you please elaborate on the "hard loop"?

Thanks again to both of you for the thoughts...any idea about internal error reporting on the MICS I might be able to access?

A hard loop is a physical loopback device installed to "loop" the signal back to the sender. The sender is either the telco or your system. If you loop to the telco, they can run all manner of tests. You can run loopback tests on your ICS, too. Its under maintenance. Make your own loopback devices both plug and jack. Pin 1 to 4 and 2 to 5. You must use 8 pin devices!
There are some troubleshooting procedures in the installer manual. Alarm codes are also explained.

[This message has been edited by jwooten (edited June 06, 2004).]

[This message has been edited by jwooten (edited June 06, 2004).]

you most likely have a telco problem, have the provider run loop back test. You may have bit errors. If someone decide to tap into the same wire that feeds this circuit this problem starts. Splicers do this when they are working pairs in the area. If you have a T1 watcher you can monitor for errors also. When the telco enters the circuit you will see errors. good luck.