atcomsystems.ca/forum Forums TDM Business Telephone Systems Vodavi Telephones & Systems XTSip with PRI using Combo Card problems.

I guess that at this point, any further suggestions would be moot since it's working. I will say that I talked to one of my techs today and he reminded me of a similar issue that we had several years ago. It didn't involve a combo card obviously, but the scenario was similar to yours.

We ended up finding out that Verizon had split the pairs on their punch down to house cable pairs when extending the circuit upstairs to their RJ48X. Basically, the transmit pair ended up being white/blue and orange/white and the receive pair ended up on the blue/white and white/orange. It still managed to work (with service calls every other day) for quite a while. It wasn't entirely the installer's fault, it was the Bell Atlantic cable splicer in 1978 when the riser cables were installed who split the pairs in a splice case. The installer just assumed that pairs 1501 and 1502 were good and didn't bother to check them with anything more than a toner and a probe.

Surprisingly, a T1 or PRI does manage to function (marginally) under these circumstances. I've even seen them continue to function with half of a pair missing, but chock full of errors.

We could get call collisions to happen if two people called in within seconds of each other both trying to get on that first line, one would get thru the other would not and it wouldn't roll to the next in the series. The lines would eventually clear but was never less than ten minutes. Never happened with the old card, we couldn't make the old card fail once, but the combo card would every time. Again Vodavi said it was a problem with the signaling from the telco, but as far as I'm concerned I just wanted it to work so leaving the old card in is where I left it. Sucks that the only option from vodavi is the combo card anymore. I don't see the telco's changing their way of doing things any time soon here.

I talked with a very good Vodavi Tech-engineer this morning about this problem..He told me that changing out the combo card with a different combo card would not have made any difference. Cox is sending something squirely down the B channel, the combo passes the bad info on to the MPB and the MPB buffer fills up and locks out the PRI and just denies calls. Reset the PRI at either end clears the buffer and the whole mess starts over again. The really bad thing is..depending on the MPB software (2.0) when the buffer fills it may deny all co calls including calls through th LCOB or Voip which requires a system reset. They are working on redesigning the combo to make it more tolerate. Trying to figure out what the CLEC is doing or not doing with the PRI to fix this or keep it from happening again is next to impossible. Apparently, many dealers are trying to get the older card which has eariler firmware to try to resolve issues they are having. Ed, this goes along with what you said about CID info on the PRI.

We didn't change to a different combo card we had originally installed a combo card which is when we got the failure, we had to go to the older pri card which took care of the problem of course you can't get that from vodavi.

I had this same issue with the first Vodavi the company I used to work for put in this same set up on a DMS. We fought and fought with Vodavi and the carrier. THe high voltage reading may have been from the fact the PRI was running across a HDSL T-1 circuit. It is true however, that the carrier would see the D-channel and the B channel trunk groups go down in the switch. I worked in a CO for 2 years, and if a circuit dropped, we would know it. The MCC would light up like a Christmas tree. It is possible if the rep from Cox you were working with was monitoring the wrong span. It doesn't matter if the circuit is passing through 5 different LECs, the switch is always monitoring the span, no matter how many DACS or slicks it passes through.