atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's Fax problem caused by RX slips. (T1/Titan5500/5ESS)

The Titan appears to be provisioned correctly (except ALMPF=99 which will never generate visual alarms should the T1 take a dive).

In this instance, assuming that the Titan and 5E are using the using the same bits clock, you could try to use the Titan to provide clocking to the CPE. It is possible that the CPE doesn't like the timing bits from the 5E.

This may be seem like a silly question but are you lookin’ for and seeing the slips on the voice T1 at the DS0 level or DS1 level?

Man Dex… I thought you had it with this one! I would have bet money on a timing source mismatch.

I am at the customer location now. verizon came and went. t1 tested clean on all patterns head to head tberd to tberd. no slips.

I believe we are doing t1 level testing and monitoring.

Should I be doing something else?

Can this be a bad extension? Can there be bad options somewhere causing this?

thanks again for the help!!!

posted from my treo.

fred

Just for giggles, on the CST facing the customer, change the timing from through to the other option (INT?).

Let's see if the CPE likes the timing bit stream from the Titan.

If no change, I'm stumped. :confused:

Thanks for the post Bryan

I also thought I had nailed it. :scratch:

What is the voice T1 connected to when it leaves the Titan on the C.O. side? Does it go directly into the 5ESS as digital or does it go to a channel bank where the 24 circuits are changed to analog and wired to analog OEs. If there is another channel bank there could be a timing issue there.
Also, what does the T1 ride on going from the Titan to the customer? Is it on copper or does it ride in something like a Litespan? That could be another place for a timing problem.
I’m like everyone else. Timing has to be the issue. I know that fax machines being served by a SLC96 will have problems is the SLC remote terminal is not set up to time from the C.O. end.

GOOD question!!!


I read through this entire post one more time to see if I could rattle something loose in my memory. (Man I wish some of you would have typed slower!!! I cain’t read that fast! )

One thing I (or us maybe) may be loosing you on is… Was the not being able to send long/large faxes the root problem here (problem with that one trunk) OR was that just the symptom that caused you to see problems on the entire T1 delivering the voice trunks?

Ok I just got back from the customer site.

Here is some added info for yas.

1) This was initially a fax complaint which pointed us to the T1 taking slips in the customer router.

2) The connection from the Titan DACS to the 5E switch is via direct cable. There is no mux in the middle. Sorry. Would have been nice and possibly the issue.

3) We tried to change the timing on the T1 in the titan to internal from through but it didn't change anything. Still got the slips.

4) We put a duplicate router right at the dmarc and still got slips. Rules out house wiring.

5) With the router plugged in at the dmarc and mapped all the way to the switch, we get slips. If my tech at the office changes the cross connects for the T1 in the Titan and maps it over to his tberd, the errors STOP. NO ERRORS!

I am being told to have Verizon verify the signaling and coding on the T1 at all points. He seems to believe that there is a hop in the circuit that is not optioned correctly. If that was the case, why is it that the T1 runs perfectly fine with data on it?

Remember:
T1 1 had voice and T1 2 had data.
T1 1 had the slips. T1 2 was clean.

We swapped the services so we ended up with:
T1 1 has data and T1 2 has voice.
T1 1 is clean and T1 2 is taking slip errors.

I am going out of my mind here!

Thanks again for the help. Hope these answers can assist.

2) The connection from the Titan DACS to the 5E switch is via direct cable. There is no mux in the middle. Sorry. Would have been nice and possibly the issue.

Still could be a bad trunk side port at the switch or the DSX-1 jack it's tied to.