atcomsystems.ca/forum Forums TDM Business Telephone Systems Vodavi Telephones & Systems XTS-IP PRI TROUBLE, INCOMING CALLERS RECEIVE BUSY SIGNALS

You might want to insist that they check with at&t's local plant manager and verify that the cable pair being used isn't half-tapped. I have one customer who had the same problems that is located less than a mile from the CO. When we first installed the system about 8 years ago, there were constant crashes, almost daily. I knew that GTE had half-tapped an existing cable to feed this building when it was constructed, so I just took a ride further down the road and followed the cable route (aerial).

Turns out that it continued about six more miles from my customer's site and yes, I finally had to open a pedestal to prove to them that the pair count was in fact half-tapped (GTE denied it). They agreed to cut the affected pairs dead to the field and it worked perfectly after that.

Until........

The customer downsized and eliminated one of their two PRIs. In (now) Verizon's usual fashion, they installed a new single circuit instead of just eliminating the second one as requested. Within a day, same song, second verse. It was crashing constantly and all that Verizon had to say was....Well, let's not even go there.

In a conference call with God only knows how many people, I was lucky enough to have a CO technician involved. He agreed to run a full test on the T1 at the frame for the night and give us the results in the morning. Oh boy was he surprised the next day in our conference call.

Although he was insistent that this was an F1 cable count, which it technically is, their plant records didn't show that my customer's cable count was a tap. I hate to think of the hundreds of hours of visits, emergency calls, conference calls, etc. that were wasted (once again). Once they moved our circuit back to the original pairs, everything has been fine.

Oh, by the way: Our affected cable pair was found to be bouncing around in the breeze; an aerial drop that fed a now-removed mobile home two miles away.

Sorry for the lengthy side-track, but I just thought I'd share this experience in an effort to give you some ammo. Vodavi has said to me many times that a problem with a PRI is always on the telco's end and I can say with certainty that this has always been the case for me. Good luck.

Half tapping....I didn't think about that. Reminds me of the time long ago when a customer of mine with 22 pots lines in hunt that kept getting ring no answer. I argued with Bell Atlantic now you know who about it for days about whos fault it was. Turns out that when a truck drove by a ped down the street, the vibrations would shake the ped and one side of line 7 would disconnect from the screw termial on the wiring block in the ped thus opening up the hunt. The next truck to roll by would shake it again and it would start working. You can imagine how much fun this was.

Ed. I agree with you. Any PRI problems that I have ever had were also always on the provider end. While I mentioned that I have had two bad boards in my past, one was obviously bad because it failed a local loop back test from the CSU. The 2nd board wasn't actually bad. It turned out to be that when I went to add the newest combo board, I needed to revert to the older revision because the XTS S/W ver 1.16 didn't support the newer one. That issue is found on older XTS posts in the forum. Neither fault occurred on an existing circuit that was previously in-service but only on new additions. And the 1st one was when I tried to use an old board that was removed from a previous installation. It had probably been mishandled somewhere along the way.

All everyone has said is probably true (network trouble). Still is he's receiving yellows and that mean's the AT&T switch, no matter what kind it is, is loosing signal. So depending on what's on the circuit, as far as monitoring equipment goes, AT&T ought to be able to see that and narrow it down. At the very least they should be able to see the LOS at their switch. I'd think by now most of the NID's would be the smart type that they can pull PM data from also. I think I'd be doing a little more talking to AT&T to see if they have access to PM data.

Thanks for the input, I'll mention this to AT&T tomorrow. They've escalated this to a cronic repair and are supposed to do more testing.

Question; is it necessary to have a csu? What would happen without it?

Thanks

The pri will technically work without a csu but not as well. The csu helps to prevent jitter and signal loss.