BCM 50 DTM / PRI Module Resets When Answering Phone

[BoLucky]

I have two customers with the same problem and wonder if anyone is having a similar issue or knows of a fix.
PRI service is provided by carrier on ADTRAN IAD DEVICE
Wired in thru cross over cables to DTM module Provisioned as a PRI on BCM 50.

When placing or answering a call the PRI resets.
System does not go down but PRI is Out Of Service for 5-Mins.
Alarms are 44, 75, 372

 

[telcodog]

Check your clocking. You need to be set to Primary External.

What are the other parameters set to on your PRI? In particular, your line protocol. You need to match what your carrier is configured for.

Typical is as follows:
Protocol NI-2 or DMS-100
Framing ESF (extended super frame)
Line Coding B8ZS (Bipolar 8 bit zero substitution)
Interface Levels ISDN
Clock Source Primary External

Of course, these must match the carrier.

 

[BoLucky]

Thank You Telcodog
Settings are set as you recommended.

Strangest thing ..It will work for most of a day and bang! Down it goes. It seems or appears like static shock triggers an Alarm and disconnects.
I wonder if I should replace the module?
Or if there were a batch of modules that may have had this problem? dont know just guessing.

Should I possibly change the clock settings because of the ADTRAN?

 

[telcodog]

Those errors are telling you that the system has lost its clocking reference. I doubt that the modules are defective but you can swap it just to be sure. I would open a ticket with the carrier and give them as much info as you can. My guess is the ADTRAN box is not programmed properly. Wouldn't be the first time for those things.

Who is the carrier anyway?

 

[oldestgeek]

BoLucky, I was getting the exact same errors on a PRI connected to a Cisco IAD. I verified all the settings with the carrier and they replaced the IAD but still was dropping the PRI. Rebooting the BCM would stop the drops for a week or several weeks but it always came back. I replaced the DTM twice, each time thinking it fixed it but the problem came back. I finally replaced the BFT and never had the issue again.

 

[BoLucky]

BFT? Base Function Tray of main unit on BCM-50?

 

[oldestgeek]

Mine was a BCM400. I just threw that out to point out that even though everything pointed to the carrier or the DTM, the actual fault was in the BCM itself.

 

[BoLucky]

Replaced DTM Module trouble seems to have gone away, No alarms for two days.
I'll keep an eye on the BFT
Thank You telcodog and oldestgeek for your responses and assistance

 

[oldestgeek]

The problem on mine went away for 2 months once after replacing the DTM. The next time it worked for 2-3 weeks, then I replaced the BFT and it's been trouble-free for over a year now.