atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's CHANNEL BANK PROB.

My T1 is broken into 24 analog channels through a Zhone 10-plex with 24 FXS channels.

2 of the channels just stopped working - no dial tone.

This is a new installation where I had to supply the channelbank. Luckily, it worked with all the default settings as I could not find anyone to install it. (24 channels is a rare setup in Canada as it was disallowed until recently. It doesn't help that the Channelbank is obsolescent.)

Now this and I have no clue how to troubleshoot. All the settings I've checked are OK but I don't know if I've missed anything. Commands are via CLI which I access with Hyperterminal.

We had a problem with a NY Tel T-1 years ago. We had a WE Channel Bank at each end and we could get only 12 channels working. The key was it was ANY 12 channels, but no more. We ran a Stress Test on the T-1 and found that it failed terribly. When NY Tel brought it up to snuff, all the circuits came back.

Can you shut down some of the (good) channels on that Channel Bank? See if the problem moves. Test the T. Try swapping dial tones and see if that has any effect.

Sounds like a good idea - it may take a day to figure out how to do this. In the meantime, I was told that if the problem is in the T1, nothing would work. I've got no alarm showing.

Looks like my info is wrong???

Is the T1 going through an external CSU/DSU? Make sure that all of your DS0s are enabled on it if so. The CB might have one built in, something to check.

I've had a few zhones that just suddenly die. It's usually just a couple channels. Sometimes a reboot solved it. Sometimes I had to go in and reprogram the dead channels.

Get an Adtran and don't look back!