sundance-communications.com/forum Forums TDM Business Telephone Systems NEC Telephones & Systems Ring trip problem - DS2000

I have a DS2000 that's around 6 years old. 2.05.00 firmware, 80025A CPU, 16DSTU, 8ATRU, and 8ASTU. It worked fine when the telco was Qwest, and also for several years after I switched to Cox cable as provider. They use Arris NIUs and I'm on a CSV system, 4 CO lines. The first two Cox NIUs were fine. Last December they changed out the NIU (the problem turned out to be a damaged cable a few blocks away, not anything at my office). With the NIU change I started having a ring trip problem -- on most calls I hear ring voltage for a second or two at the start of each call, all lines. Cox just changed the NIU again, but the problem persists. I've checked everything I can think of. Talk battery is about 48.5V, ring voltage 56.6VAC at 19.9 HZ, both read with a Fluke 189 RMS meter. The ring waveform is a clean trapezoid. Changing line length from long to short didn't help. Cox can't find any problem and has no clue.

I'd appreciate any suggestions.

Martin

Your ring voltage is on the low side.

Are the lines pots or channel banked?
We had this problem when customer changed providers and went form pots lines to T1 channel bank. Provider was able to dial into their CSU DSU and change the settings for ring voltage.

Dan... trying not to sound ignorant on the installation end... would ring voltage regulators help here if copper?

way past due for a software update , thats where I would start

also take a look at your ground

Thanks for the replies.

As to CO lines, they come from a cable box on the side of the house. The cable company says they have the voltage set at max and there's no way that they know of to set the waveform to sinusoidal -- the last tech asked every person at the test desk about the waveform. As to ground, it's #6 copper back to the electrical service. The cable box is grounded to a clamp on the service lateral conduit with #12 copper.

I'd love to upgrade the software; however, the notes on the Nitsuko site say that I have to go the PC card route to upgrade from 2.05.00. I have a PC card that Nitsuko sent years ago around here somewhere, but it might take a month to find it. I also can't tell from the release notes if I can upgrade to the 3.xx.xx series -- there are comments about requiring a B rev CPU, but I can't tell if that's just for a few features or if it's for the whole 3.xx.xx series. Any info on what upgrades and upgrade methods will work would be appreciated.

first you need to use the card to go to 2.11.05

not sure about going to 3 without reserching it

I missed the first part about these being VOIP lines
theres the problem , they are cable providers not telco providers and basically don't have a clue

I had one customer VOIP worked great for a couple of years then all kinds of problems nobody could solve

finally went back to real phone lines from verizon

On going to 2.15.00, is it possible to dump the software to the PC card using a laptop or do I have to get the card loaded by Nisuko?

You would need one of the PC upgrade cards cards from NEC to do the upgrade.
Have you considered just getting a "b" processor and going with 3.22.10 It the long run it may be easier then getting the upgrade card plus you would be able to use the pc admin program and have the updated day light savings time.

If you need help obtaining the card (upgrade or new cpu) you could contact one of the mods via a pm or call your local installer

Stacey,
Sorry I can't answer your question.

Martin,
The problem started when the customer changed providers. If this is the highest they can go with ring voltage you can bet other companies using this provider are having difficulties. Upgraded the sofware or processor is not going to help. Have you pulled customer equipment from the dmarc and tested with your butt set? If you have how loud was the ringer when you called in? Compare it to normal working pots line.
Your problem will go away if the ring voltage is kick up. I'll bet money on it. 56.6 is to low.

Dan S

Martin,

I would like to help clear up a few things about the DS2000.

1) Version 3 software requires the rev. B LCCPU card.
2) The rev. B LCCPU card can use the DS Software Update utility to load new versions of software from a PC. A memory card is not required.
3) When upgrading from version 2 to version 3 software, the system must be reprogrammed. The databases are not compatible.
4) The line length setting (long/short) adjusts the hybrid balance. It has nothing to do with line or ring voltage issues. It is important to set this correctly to provide as little sidetone as possible. This will improve the call quality and speakerphone performance.

IMHO, I seriously doubt your problem is with the system software. It sounds like the ATRU card is not providing a low enough impedance to trip ring during the ring interval. You hear the ring on the audio because it's not answering the call until the silent interval.

There have been a few improvements to the ATRU cards since your system was installed. Have you tried a new ATRU card?