atcomsystems.ca/forum Forums TDM Business Telephone Systems Nortel Telephones & Systems Nortel MICS with 4.0 PRI Issues

This system changed about 7 months ago from one PRI provider to another. After the change, the last two channels of the PRI started locking up, 17 and 18 at first. You would dial 9 and get dead air on those channels, but placing them on hold and dialing 9 again would get dial tone again.

The ILEC's router has been replaced and settings have been played with. We've moved the channels around, for a while the customer was using 15 and 16 to dial out on while 17 and 18 were left idle and eventually 15 and 16 locked up.

It seems neither the carrier nor the system sees the channels in use, so when you go off hook they are allowed to connect, but you get dead air and can't call out.

Any hints or suggestions would be great. This has been on going for months, so ask any questions to fill in the blanks, I'm sure we've done the test. We even had a TBerd out at one point.

Naturally Nortel says it's the carrier, the carrier says it's the system.

4.0 was basically recalled right after it came out..Your gonna have to upgrade to at least 6.1 if not 7.1 to fix any t1/pri issues...If you talked to anyone for tech support they should have told you that.

Did you try to change Descending order for Ascending to see how system is going to react?
Besides your dial tone is a system feature not a PRI depending. PRI doesn't provide you a dial tone. Make sure it is NI2 not a NI1 protocol. If this a PRI why channels 17 & 18 not a 23 & 22? Is it partial T1?

Here's a stretch, but I've seen it. Carrier only allows "x" number of minutes per trunk/month!

Tech Support did mention upgrading, but they weren't convinced it was going to fix this particular issue, so we didn't jump to it, especially considering the cost versus annoyance factor and the fact that it was previously working for nearly 10 years before they changed carriers.

We have not changed from ascending to descending yet but we did leave channels 17 and 18 in PoolB while placing 15-1 in Pool A and the problem occurred in channels 15 and 14 at that point. We purposefully left 16 dead to "separate channels" just to see what would happen. 17 and 18 worked fine dialing 8 outbound. It did take about 6 weeks for the problem to present itself again though after changing the pools.

It is a partial PRI. Channels 1-18 are supposed to be used with 24 as the D channel.

Checked with the carrier and they do have an allotment of LD minutes, but nothing that will prevent outbound, they just go up in rate after surpassing their minutes.

You just admitted that 10 years you had no problems. It is proving that problem with provider. Either protocol changed or Router problem.

I'm in agreement with VAD, but that said....

You could spend an enormous amount of time and customer frustration on this.

Trying to be a friend of the customer and you, please upgrade to 7.0/7.1, the software is not that much money and your time is worth something.

Whoever sells you 7 should lend you a 6.1 upgrade software you can return. First you go to 6.1 (or lose every bit of software) then upgrade to 7.0 or 7.1 whatever you can find.

At that point, both you and the customer know you have the latest and greatest and it falls on the telco.

Probably not the real issue, but can you swap out the DTI card and let that run for a while? If you have very good relations with a supplier they can mark that card as theirs and rent it to you for a month.

With something this weird, it is really trying to find any and all possible cheap solutions and my first try would be the DTI card. The more you prove you have done, the less is on your back and ultimately you need to be the white knight that proves where the problem lies, the carrier won't.

I have a site in the valley where Line 1 (channel 1) on the Adtran keeps freezing up and the Telco kept saying it was the system. That channel 1 freezes up if it is attached to the 2nd or 3rd dial tone position on the ksu. The trouble follows the channel 1 position no matter where you punch it down.

The telco doesn't know what to do, they replaced the Adtran and the AT&T circuit pairs, still no matter where you put channel 1 it freezes that day or the next. The customer no longer considers their equipment could be bad and I have no idea where the trouble could be other than in the 5e switch itself. Sometimes there are real ghosts.

Bunnie,
What do you mean by "punch down a Chanel". Do you have Adtran or Chanel Bank?