I'm working on a small PBX install and I'm having trouble with two of four CO lines which are not disconnecting when the caller hangs up. In my conversations with the Verizon CSRs the only thing that seems to be different with the service ordered on the lines is that the two lines which don't disconnect cleanly are set to hunt to other lines on a busy. Any clues on how I might go about resolving this - I'm doing this job as a semi-knowledgeable amateur for a non-profit organization, so there's not a lot of budget to play with.

Details:
Four POTS lines - A B C D

A, B and C have caller ID and hunting A -> B -> C

D was provisioned solely for the fire and burglar alarm systems and has no enabled "features"

When testing each line individually connected to the PBX, A and B do not seem to be disconnecting quickly when the caller hangs up, but C and D do.

I've worked around the immediate issue by reprogramming my auto-attendant to disconnect on no entry timeout. However, all would be neater and cleaner if the lines would signal properly so that the PBX could know to hang-up and send a disconnect signal to the AA.

In former GTE territories, this feature is only provided if the lines ordered are trunks. If they are ordered as simple POTS lines, they sometimes don't add this feature arbitrarily. You have to ask for it. I had luck in getting their repair people to understand what this feature was and to put it on. They refer to the feature as "cancel on disconnect". If you are in a former Bell Atlantic area, then I really don't know what to tell you except to try the same thing with repair people.

This is not a feature that incurs a monthly fee.

You are fortunate to have two lines that work properly and two that don't so that they can do a complete comparison between them. That's better than most people get.

And, of course, it COULD be the PBX! How about make and model of the PBX. PBX programming could be the issue, have you tested the troublesome lines on the ports that have the non-troublesome lines. John C. (Not Garand)

If you know the type of switch that Verizon is using and if you supply the type of PBX, maybe one of the network guys on the forum could check for compatibility issues. If you’re in SE Pennsylvania, my guess is that you are served by a 5ESS. There is a compatibility guide for the 5E that lists the various types of CPE and PBXs. Sometimes this document is helpful in resolving this type of problem. Unfortunately I no longer have access to this documentation.

I won't argue that it could be the PBX. Sorry I didn't provide enough detail in my previous post - I did try each line connected directly from the NT to the same port on the PBX - only two of the four lines - the ones with hunting failed.

Anyway - here's the PBX info:
Toshiba DK424 with a B3C Processor

Steve:

Verizon is using Nortel soft switches in that region that have been causing all kinds of problems. These switches are only being used to handle inter-office trunking as far as I can tell. There is a lot of information that's not being conveyed between end offices due to this.

It's pretty easy to test to see if you are receiving the disconnect signal: Just connect a toner across the line under test (don't turn it on) and call it. You will see ringing voltage cause the toner's LED to flicker. It will go dim when the call is answered. At that point, hang up from the calling phone and watch the LED. Within about ten seconds, the LED should go completely dead for about half a second. If it doesn't, then it's Verizon. If it does, then it's in your system's programming.

Program 15 in the DK does specify for each trunk if CPC should be detected. By default CPC detection on the DK is off. Double check the programming on the DK.

Being from SE PA too I know all to well the mentality of verizon around here. It one took over a month to resolve a CPC problem.

At least you have 2 that work. Set up a vendor meet with verizon and show them the lines that work and say the other ones have to be set up the same. I think the COs here called it COD (cutoff on disconnect)

Verizon, Sprint do not activate this feature unless it is requested, then, you have to "explain" what it is you want... :bang:

Could it be that maybe two of those lines are groundstart instead of loopstart? I'm assuming no since you've probably tested them with a regular phone already.

Jeff