sundance-communications.com/forum Forums TDM Business Telephone Systems NEC Telephones & Systems NEC DSX-80 Occasionally Dropping Calls

A customer has been reporting about 3-4 dropped calls a day from their recently installed system.

It's happened once while we were talking to a customer. On my end I heard a click and then silence, and after a few seconds a ring and the telco's generic message "try another number."

Firmware is at 1.1.21. Ground instructions were follow exactly as the hardware manual stated.
3 Lines. BellSouth is the provider.

The last thing we tried was switching out the COIU card with another. DSL also comes in on one of the lines and we tried some extra DSL filters on that line. We're going to check in again with the customer today.

Anyone have any suggestions on things to try? This is our first DSX system install but we have a lot of experience installing and programming panasonic pbxes.

on a UPS ?

Yes, we use an APC ups.

always the same line ?

try swapping the lines in the dx80

( you can go in and swap the line appearance so the customer doesn't notice )

have you looked at the loop current ?

How are you co lines protected going into the switch?

Since a majority of the calls come in on line 1, I think the reports are that the line 1 is disconnecting the most but I seem to remember disconnects have occurred on the other lines.

The CO lines are going through a line surge protector.

After talking to the customer again, they said they had one disconnect during that day. So we're still not happy with the results. Also I would like to add that these 3 CO lines were used in their previous system which was just analog. And it worked perfectly.

Checking loop current is one of the things we're going to pursue next.

Thanks for your help.

when the call disconnects have them push the line button and see if the caller is still there

I had a customer with a similar problem on a ds2000

look at program 1613 far end disconnect , you can tweak it a bit but be careful if you get it too high the line wont disconnect .

Ive seen this problem on the product line going back to the ds01/onyx vs and it can be a PITA to resolve

good luck

The reason I asked about the co lines I had a customer with a DSX-80 dropping calls traced my trouble to the co line protector,replaced it no trouble with drop calls.