NI2 PRI

[cilcomm]

I have two NI2 PRI for the DID/DOD coming into an Option 11C 25.40 switch. The second PRI ( ch 25-47 with secodary D ch) seems to be having tons of error messages, but mainly on the weekends. The first PRI has had no LOSFA or Slipped frames ever. We have had Verizon do a stree test on it and perform hadr loop tests to see if there is a problem with it but found nothing. After their tests last week, I had no trouble and no errors until today(saturday). The same thing happened last time we had tests run on this span. I have checked the programming on both spans and checked them against each other. I have replaced the extenal Adtran CSU, cabling and TMDI card. Even moved the TMDI to another slot and reprogrammed it but the same thing keeps happening. Has anyone else had this problem or anything likeit?, if so did you find a way to correct it or at least locate the problem?
I have also reset ans INI'ed the system to eliminate a
'ghost in the system'.
I'm at my wits end with this. The errors and slipped frames are causing the TMDI to go into disable and Ihave to manually rest the card and dchannel.

 

[PERRYPJ]

UNPLUG THE RJ 45 GOING INTO THE VERIZON SMART JACK PLACE A LOOPBACK JACK ON IT AND LET IT RUN THE WEEKEND SEE IF THERE ARE ANY ERRORS MONDAY MORNING. THE DCH CHANNEL WILL BE DOWN BUT THE T1 WILL CONTINUE TO FUNCTION AS A T1. AFTER YOU PLACE THE JACK ON THE RJ 45 CLEAR YOUR ERRORS IN LD 60. IF THERE ARE NO ERRORS MONDAY MORNING PUT EVERYTHING BACK AND BRING YOUR DCH UP, THEN CALL VERIZON AND TELL THEM TO FIX THERE TROUBLE

OLD ROLMEN WORKING ON NORTELS

 

[johnpoole]

have your replaced all the cables? not going to help, but don't skip any. bad cables usually show up as bpv.. what is unique about the weekend. no traffic, high traffic? it could just be a fluke that it's an overtime problem, but i don't like to beleive in chance, usually a reason for the cycle.. i had one that (pri) that only had trouble under high traffic, after checking close, it was only used under high traffic. a stress test helps and may isolate a problem. they can miss problems. wait untill telco is not looking (me)and swap the smart jacks. you've done any testing i can dream of. have you moved the d ? i had a strange problem where the 4th user on a d, took hits during certain backup procedures.. only when the symposium and and call pilot did a backup on the same cycle, not the same dnum, but a high request int, and dnum 15.. i have used contacts to have a new pri installed, brought it up, then turned the one off a carrier couldn't fix.. making sure they couldn't reuse cable pairs or slots... 98 percent sure that the trouble is VERIZON , have them do non intrusive testing for 96 hours, starting Friday am. remember your paying $$$,your the customer, other companies want your business. ps not me you complain to much LOL

john poole
bellsouth business
columbia,sc

 

[acewarlock]

I have had that same problem and Telco keep telling me it was my equipment. I swapped the the RJ 45 cables from both T1's and the problem followed the swap proving it was a Telco problem.

 

[cilcomm]

perrypj,
If I loopback on the switch side, I shouldn't see errors because no one can call out and no calls coming in. Hence no traffic, no load, no errors..... i am not sure about that one.

Johnpoole,
I may very well be a high traffice situation. The students at this campus are calling home on the weekends. Could this be isolated to a DID DN? maybe it is not provisioned correctly on the PRI?

thanks all for the input. it is good to know I am not the only one with this type of problem. If I find a cure or definite cause, I will post it.

 

[MonkAZ5]

I have ussually found that slipped frames are caused by timeing. Check where you are pointing the timing of the T-1. Compare with 1st channel. You should either be timing from switch or the t-1 Span. Not sure on Meridian, but your primary source of timing can come from the Verizon T-1 (one). Then set secondary source to the second T-1 (two).

 

[johnpoole]

in a nortel, timing can cause slips, but i've never had a clocking problem affect a single pri, clocking is set in load 73, test in load 60 ssck 0 ssck 1, all pri's use a single clock source, the backup is used only if the pri clocking link goes down. at times if the switch goes to freerun, all t's will slip

john poole
bellsouth business
columbia,sc

 

[cilcomm]

Here is an update,
I have been monitoring this PRI span for while now and the problem seems to be intermittant. Lately, I am getting huge error numbers on my Slips and frame alignments. This causes the span to go OOS and I have to manually reset the span. I have Procomm Plus running at the terminal on site and when I scroll back through the buffer on the days that the span goes down, I see a lot of DCH4 OOS and DCH EST messages. I have had Verizon do more hard loop testing and stress testing but they still say they cannt find a problem. I am at a loss for what to do next. The First PRI still has not had any problems, it is only limited to the 2nd PRI with thw backup DCH.

 

[johnpoole]

swap the two pri's in your switch, see if the trouble stays on the 2 pri or moves with the central office...

john poole
bellsouth business
columbia,sc

 

[cilcomm]

Do you mean swap cards and move the Clock card too or do you mean out both PRI and build new?

 

[johnpoole]

no leave the switch hardware the same, move the software and the plugs on the smart jack. by doing that you will prove either that your hard/soft side is good or bad

john poole
bellsouth business
columbia,sc

 

[rfwhite]

perrypj,
I'm reluctant to even mention this since it sounds so crazy, but- recheck your grounds. We had a similar problem on a DS-3 and it turned out to be a faulty ground on the mux rack.

 

[cilcomm]

I still need to swap the clock cards to the card that currently has the problem, right?

 

[ajnd]

Had a similar problem a while ago. It turned out that the telco had a ami programed in the middle. As long as there was trafic it was okay, but when it got all zeros the b8zs would do a bipolar and the ami would see it as an error. B8zs is suppose to do a bipolar to tell the rest of the equipment that it is okay. The telco would do a lot of tests but would not do a zero test. They would try to pump a lot of ones in the stream. Hope this helps

 

[cilcomm]

Thanks for the idea for the zeros test. I will call my contact at the cetral office next time I am onsite.
The past 2 days have had no errors at all and I know that here are pplenty of times during the day that this Span has no traffic. I have never seen the entire span fill up since it has been in service. It probably only sees about 6 calls at any one time.

How can the LEC program an AMI in the middle of the span? I thought when you purchase a full PRI, you can only have a B8Z span or an AMI span...never half/half.

 

[cilcomm]

Still having troubles. The T-1 has tons off slips and errors now and I have to manually reset the card a least once a week and do maintenance on it every other day to keep the span up. When the span does go down however, the customer can still get out temporarily on the span. The call goes to static then drops the call completely. When I check the status of the span, it says it is Disabled, usually because the error counters have exceeded their limits. How can the switch set up a call on the disabled PRI? Maybe this is a clue to the real problem. Any help would be appreciated.

Thanks

 

[johnpoole]

did you change all the patch cables? check everything again. START over, day one, one of the items you have replaced or checked is still bad. even the tmdi, etc. another thought. dis the tmdi dch msdl and enable with a fdl. in 96.. might just need a new look at the entire thing

john poole
bellsouth business
columbia,sc

 

[cilcomm]

rechecked everything again as far as hardware and swapped hardware again with known good hardware. ( cables, patches and tmdi card) still having trouble with the LEC ,since this a government site, i cannot get the paper copy of the programming for the Span from them, I have to go through our lovely government agency known as CMS to get that and it takes al ong time to get the proper response bevcaue they have to go throu lots of paperwrok to request this type of hard copy apparently. I thought that the MSDL was the onscreen messages you get on the Dch. so what goods would that do me to dis the msdl on the dch? just a question....

 

[srmega41]

cilcomm,

How does the span enter your building? One thing to check is what ajnd suggested above about the signalling. Any time you have a physical or logical interface, options can be changed. One example would be a T1 riding a DS3 into your building. Some form of mux has to break the DS3 down to a DS1, or T1 (same connection, different delivery method). There are options on that mux for each DS1. We had a span that acted very much like you describe, and it turned out the Muldem was optioned for AMI where the span was ordered B8ZS. The problem was made worse by the fact most tests the telcos run deal with loss of frames, so they run QAZI(sp?) or all 1's or all 0's. Most of these tests will not indicate a problem.

I would recommend asking your provider to do a Round Robin test. This apparently is the most complete test that can be run, and will indicate an optioning mismatch, if there is one. We have some old AMI voice T1's that go down because some tech did a PM and swapped a card set to B8ZS. Traffic is fine until nothing is active, then the bi-polar errors start up. One issue lasted over a month, with the telco pointing fingers at us the whole time.

I hope this helps,

Scot M.

 

[johnpoole]

the multi test causes problem because when the pattern changes tested ignore those slips, when the pattern is clean, the slips.. quzi works almost all the time. the best test i usually run is a simple all ones, and instead of watching just errors, look at the freq. it will run 1.54 but if the span is set mismatched, it will drift, 1.543 1.544 etc.. that happens everytime you have a span set mixed at multi points, if you read the original set up plans for changing esf to b8zs from telco, the need to change central point was brushed over, as long as each end matched.. and that will pass most test.. another finer point how far is the "smart jack" from your switch. an extended demark can cause problems, i have moved the telco loop back on more then one switch to shorten that span. (you have to be a regulated agent to do that) that is caused by the voltage difference before and after that point. i had a case 10 years ago where i ran a cat 5 3 floors to bypass very old tie cable, and moved the smart jack, fixed a problem that was a year old, that one was on a old cisco 2500, but the symptoms were the same and cli's post is on the money 99 percent, the multi test may have been cleaned up since i used to install the telco end before i installed the user end

john poole
bellsouth business
columbia,sc