sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's PRI troubleshooting

Hey gang, I need a recommandation. I need to see the status and of the B channels and the data on the D channel. I have a PRI that is acting up and losing the connection with my fax server. I have the PRI connected directly to the fax server.
I have had Carrier test the T1 and verify all the setting on the T1. It all check out OK. It will work fine for days and then I will have issues with it day after day. I am think of some kinda of test box that I can put before the fax server to see what is going on on the channels.

Thanks in advace,
Leapg0rf

Testing an intermitten trouble on a T-1 can be a pain. If it were good when testing sure it's a TOK. Have them monitor the T-1 so when you have failures you can tell them when so then can check the monitor. If this is provided by AT&T (the long haul) there are monitors on the T-1 24/7, I can't speak for others.

I can't think of any portable appliance that you can simply connect outside your fax server to capture the PRI D channel messages. I suggest creating an accurate log, precisely identifying when these troubles are occurring (day/hour/minute). Provide this information back to your service provider. This will assist them in locating specific output messages from their office equipment in direct regards to these errors that you're experiencing, to include what is causing these troubles.

Couldn't he use a T-Berd to monitor the B/D channels?

On second thought, might be over-kill for one time use.

I know that with a sangoma T1 card you can run D or B/D channel logging. Probably too much learning curve for what you want tho. Plus you'd have to have a computer to run it on/etc.

I have found out that if you complain enough they will monitor the loop for a period of time (24-48hrs) for errors. Down here you have to work for that kind of customer service tho.

I sure wouldn't worry about the channels until the T-1 was monitored and determined to be error free, which I don't think is going to happen.

Most of the models of T-bert that are in circulation amongst the carriers we deal with are for testing the T1 transport pipe only. It will test the T1 for slips, errors, Run 1s and 0s to the CO for testing. I haven't seen any that did protocol analyzing.

SBC\at&t in our area says they have only a few true protocol analyzers in their stock for diagnosing PRI problems. The T1 can be running perfect but the protocol set up from the CO be can be different from what the customer premise equipment is expecting the circuit will not function. I've seen D channels astablish but B channels would not function. You had to have a protocol analyzer to drill down through the various signalling layers to find the point of failure.

If it was my equipment I'd have the carrier explain what they see when it fails. Make them come to site with a protocol analyzer and test thoroughly. Alot of smart jacks these days keep historys to see which side of the DMARC the failure is originating from. I'd bet on an intermittent T1 pipe issue. If the circuit works at all it's not going to be a protocol problem.

Depends on what lid you get with the tberd. They can break out anything, for more money of course.

It's still an excessive amount of money just to see what's going on with the line.

leap: If you call them enough they will either disconnect you or fix it. My bet is they will finally have someone take a look at it.

I sure wouldn't recogmend buying one unless you were going to get a lot of use out of it. If push came to shove I'd rent something to prove the trouble. Don't think that will have to be the case here though.