PRI goes down every 4 days...Why? 3

[Pats14]

I have a customer whose has a 0x32 and 4.1 software. They had been running a AT@T PRI circuit for years, and the had no issues. The customer changes to a different carrier(XO), and now every four days or so the PRI drops, they unplug the Norstar, plug it back in and they are good to go for the next four days. We have changed the KSU(but put the old software back in), the combo card, the DTI card and ran a new cable to the demarc. The clocking is set to primary. The norstar is running B8zs, and ESF, which matches the circuit parameters, there is no CSU, so the internal Norstar one is turned on, we have put a T1 watcher on it and the circuit is error free...until it drops. Any ideas?

 

[jgideon]

do you actually get carrier fail (i.e. t1 gone), or just not able to make calls? It could be that the B channels are being disabled. I seem to recall a discussion about b channel messaging needing to be disabled (i.e. maint messages) with certain PRI configurations. You might try searching in this forum for that.

 

[AnnMGrass]

Have you checked the vintage of the DTI cards are different from each other? You said the card was replaced. If not, check that. There were issues w/DTI cards. Be sure you have a newer release of the DTI & services card. Also, be sure everything is in synch w/the carrier. Changing to another carrier can have effects on settings. Be sure the PRI is set up w/the correct settings and that the carrier is routing incoming calls in the opposite direction of the outgoing calls from the Norstar (Norstar by default goes from channel 23 to 1). Also be sure they are NOT routing them to random channels - conflicts can occur. Check the error and network logs for any alarms/events. Has the carrier tested the D-Marc?

 

[oldward]

If you go into System Test Log in Maintenance and find events like EVT799 00XX00S7, it is possible the CO is doing testing of the b channels at midnight.The 00XX part is the individual line number in hex. Also if you go into Link Status and the b channels show "far" that is another indication of this testing. The number of channels showing "far" will build up till you can't make any calls, and will have to restart the system by cycling power or go into System Diagnostics and restart.
I had about a dozen sites here in Phoenix doing this and had to call Qwest and give them all the circuit ID's and had them turn of BCAS, then had no more problems.