atcomsystems.ca/forum Forums TDM Business Telephone Systems Nortel Telephones & Systems PRI Issue

I have a MICS 7.0 with a PRI circuit using 11 b channels and 1 d channel. The system worked fine for roughly 9 months but now the customer is having an issue where every hour, about 15 past the top of the hour, you cannot call out for about 5 minutes nor can calls come in. the customer also states they get a "half ring". I figure this happens when the lines become available again. I looked in the switch and no LOS, OOF or other alarms report. I do get a code of 310 under the system test log when this problem occurs. I replaced the 6 port fiber combo card a few months back and the problem seemed to be resolved, but here I am again with the same problem. I have had a vendor meet the last time this happened and the carrier does not see any issue occur when the lines drop. Any thoughts or direction is greatly appreciated on this THANK YOU.

Does powering down and back up let you make and receive calls after the glitch happens?

I have not done a power reboot since the combo card was installed. The lines do become available after about 4 to 5 minutes after they go out. I will be swapping out the DTI card this morning. I researched the event code 310, and states "bad stimulus message received by the DTI card. Where is the DTI card receiving the Stimulus message from? The carrier, combo card or somewhere else in the MICS?

I miss-posted in my original post. The software is 7.1, not 7.0. Not sure how much of a diference that it makes, but you never know.