Noise on LS/DS trunk cartridges

[DueE]

We had a noise problem on trunks using the old LS/DS cartridges. Recently we changed it out with Global cartridge and it solved the noise problem but a new issue
developed. This trunk cartridge has 3 CO lines terminating and the 4th port has an
analog station from a Lucent PBX. Line 4 is assigned on all the Norstar phones and
approximately every 15-20 minutes there is a single ring that occurs on all the sets that have A/R for the 4th line. We put the old LS/DS card back in and the ring problem stopped but we have the noise back on all the lines. Any suggestions or ideas on a solution? Could it be from diagnostic tests on the Lucent side?
DueE

 

[tfccom]

Hey DueE,

It could be a couple of things. First of all, the Lucent could be doing a test, but I don't think that that's the problem, mainly because few Lucents actually poll the Trunks for ring voltage/dial tone/loop current, unlike the Norstars which do so quite often. It sounds like there is quite possible a ground loop/voltage difference. If the two systems are on diferent power circuits, then the difference in ground voltage could be just enough to trip the ring detector on the Norstar...

Give me some details...

Hope This helps!

Trevor Farren
TFC Communications

 

[dsweet]

Check the Lucent analog port to see is it has testing turned on. That more that likely is the problem

 

[DueE]

Thanks for your suggestions.We'll check it out and I'll let you know what we find.
DueE

 

[tfccom]

Hy DueE,
dsweet may be right, I misread your post; I thought your prob was out of a trunk on the Lucent, not a staion port...however, I've installed both brands, and only a handful of Lucents have port tests, so e-mail me with the type of system (Partner, Definity, etc, etc) and maybe we can be of more assistance!!!

Sincerly,
Trevor Farren,
TFC Communications

 

[DueE]

TFC, it's a G-3-51.
dsweet, their tech said testing is not on.
??DueE??

 

[dsweet]

Try putting in a new LS/DS card, not sure what the Global Card. Also how is the circuit delivered to you? Is it an OPX? If it is have a look at that circuit, it might be in trouble or pair reversed. Let me know if this helps.

 

[Guest_imported]

Some incompatabilities come from analog ports not having the same characteristics that a CO LS trunk has. You should check the Lucent against your COs - what's different? What model of KSU are you using? Sugestions from dsweet and Trevor Farren are really on the money. If Lucent is in OPX mode and the wire run short, the Lucent could be sending too much voltage to the Norstar. Or could be a bad line balance from the Telco?

 

[DueE]

Using a CICS 4.2. I haven't gotten any answers from the field concerning if it's in OPX mode or short wire run. We are vendor for the Norstar but not the Lucent so answers about it are not immediately available.
DueE

 

[Guest_imported]

You might try posting your original question in the Avaya section of PBX Info... see if something interesting turns up.

 

[DueE]

The new global analog trunk card (GATC)is a new release(Dec01) from Nortel/Norstar that is to replace the current LS/DS cards, it corrects some new issues as a result of newer technology. "in the GATC a newer Sigma Delta CODEC provides better audio performance...new isolation techniques to provide isolation btwn lines and ground..." it HAS cleaned up the white noise that we have experienced in some installations, but caused/allowed another issue in this one.
We flipped the pair coming from the Lucent and the ringing stopped for 1day but now it's back, right on time, every 15 minutes. We are going to half-tap a analog set on Lucent side in hopes that it will see the set and not test the line.
DueE

 

[Guest_imported]

DueE,
Did the half tap set work?

Rgds
PhM

 

[DueE]

Phone Man, so far so good...no ringing for the past 24 hrs! :-D
DueE

 

[DueE]

The half tap set appears to have solved the issue, there has been no ringing on the Norstar side since it was installed. TICKET CLOSED, LESSON LEARNED!!!!
DueE

 

[Guest_imported]

Cool. I think we've all got something from this.

PhM