Inbound "noise" problem

[jmcooney]

We have an intermittent problem on inbound calls (DIDs via PRIs). There does not appear to be any rhyme or reason to when you get a high pitched noise (similar to a fax tone) in the "silence" space between rings. I am able to duplicate the problem with my Verizon cell phone each and every time. I can not duplicate the scenario with my Nextel cell phone (nor my land line at home). I have received many complaints about this problem (and the originators have been both cell phones and land lines). Of course, there is no consistency so neither the PBX vendor or telco want to take the problem.

I asked our PBX vendor to look at the problem. They were unable to come up with anything. I called telco who indicated the PBX provides the "ringing" back to the originator. I actually believe I heard this before. Does anyone know if this is true (which would mean I could hold the PBX vendor responsible to resolve the issue)?

Any ideas on the best way to troubleshoot this issue?

 

[TheWorkingMan]

What if anything has changed?? Did you upgrade?? New hardware? Anything??? Next what kind of PBX 11, 51, 61, 71, 81???? If you are 81C with CPP processors and FIJI you need to look at the DTI/PRI cards. They all need to be ventage AG. Also need to look at your Fiji cables. Make sure that you do not have too much cable. Next you need to look at the Fiji firmware. It should be version 19. Then you need to look at the Fiji cards, they need to be ventage AC or AD. Then you need to look at your clock contollers. They need to be NTRB53AA's They should be in group 1. All of this is for a 81C CPP with fiber!!!

Check that and repost your findings or tell me if you don't have a 81....

TWM

 

[jmcooney]

It is a brand new site (went live Tuesday, Feb 22). It is an Opt 61C w/Succession 4.0 (so I guess it is really called CS-1000M Single Group).

 

[shbshb]

We had this same problem on an 81C and it ended up being a bad Conf/TDS card. We replaced that card and all is working fine now.

 

[janaya]

I have seen that problem too and the conf/tds card replace does resolve. Can you dch message trace to see if it is coming in on specific trunks or is it random on all your inbound trunks.

John

 

[johnpoole]

with pri, the switch ask the vendor to send ringback, i only send ringback after answer supervision. either was, how many groups how many conf tds packs, and then try to isolate to a group or cpu then the pack..

john poole
bellsouth business
columbia,sc

 

[tellyteck1]

do you have an expansion cabinet? If so, Nortel has issued a document re: white noise. They came up with a patch to fix that.AJK

 

[jmcooney]

First, thanks for all the hints on the Conf/TDS card.

After disable/enable of DISX without results, we looked at the card itself and the appropriate settings from the NTPs which are as follows:

NT8D17 Conference/TDS Card
Companding law Jumper at J3
µ-law (North America), A-law connect pins 2 and 3
Special cases connect pins 1 and 2

We found the jumper connecting pins 1 and 2, but it seemed the jumper should be connecting 2 and 3. Moving the jumper solved the problem.

BTW - does anyone know if the NT8D17 operates in primary/failover or if they are both active and used by loops in the same core/network module?

 

[johnpoole]

they take calls from the loop the reside in. i don't see haow a jumper could cause that problem unless it was just a bad connection. if it was hardware, it would happen on every call tha thit that loop. reseating the card can sometimes be the needed fix.. the conf/tds card is not active for the duration of a normal call, just the setup

john poole
bellsouth business
columbia,sc

 

[jmcooney]

I agree it made no sense that it did not happen on every call (and you are correct that the call was fine once connected, it was simply "noise" during the ring cycle).

I suppose it could be the reseating of the card instead of the jumper, but very strange that we would need to do it with both cards.

Any idea what the jumper should truly be set at if you think the changing of the jumper was not actually the fix (or does the jumper setting not really matter)?

 

[tipopen]

Strange but true. We have had numerous complaints on new installs only. All of them come back to the jumper being set wrong at the factory. The one I was chasing only had the tone on calls from Cingular and Verizon wireless calls. All other calls were fine.

Jim