Channel Lock out

[NYCTechie]

I need a little insight regarding an issue with my carrier, we have a Loop that contiuously locks out channels.
We have an option 81c

Here is the scenario.
changed "layer 1 flag" from "yes" to "no"
We brought circuits back up and tested:
B-Ch was busied out by MCI and but showed as "idle" on the Nortel
B-Ch was busied out by both parties and only released by one. In this test the other party did see the remote lockout.

As a cross reference we checked the programming on the "T" without issues and the programming matches, Just looking for a third person opinion.

Thanks in advance

 

[johnpoole]

pri or t?

john poole
bellsouth business
columbia,sc

 

[NYCTechie]

PRI with a D channel NI2.

 

[NYCTechie]

any takers just need another point of view is all

 

[vztech]

D-channel establishes fine? what if you tried changing the IFC.also try bypassing the CSU when making the tests.
Try FDL the MSDL again.I have found 95% of the time it's the carrier.Not to say I don't make mistakes.

good luck

It's only dialtone-VZ

 

[telecomnorth]

Channels going into a lock out is usually a sign of T-1/DS-1 issues. Make sure the signal (DS-1) on the T-1 is running clean.

Had a T-1/PRI recently that was receiving 30 to 60 CRC errors per hour from the network. The first sign of trouble was channels used for outbound calls would intermediately lockout. Once we got the carrier to correct the "loose wire on the frame" problem all runs well.

Check your LCNT counts in LD 60 but keep in mind that these are just peg counts of maintenence limit thresholds and not peg counts of actual errors. Some CSUs keep track of actuals errors. Otherwise T-1 test equipment will do the trick.

 

[telecomnorth]

Also, can you clarify if this T-1 is working for some calls or are you not able to establish working B-channels?

If nothing works look closely at the PBX configuration particularly the D-channel protocal and make of central office settings in the PBX D-channel programming.

IFC(d-channel protocal): NI2 or ESS5 are two common options. D100 or D250 for Nortel DMS CO are also used with some carriers.

Co_Type: STD=Nortel ATT=5ESS Only use ATT if the carrier states that the CO is a 5ESS. Leave at STD for other makes like Siemens(??? I think). The CO_type prompt will appear with NI2 protocal.

And remember to software download configuration changes to and MSDL cards involved.

 

[itsnosecret]

Depending on the protocol used, if you set the A&B end incorrectly the restarting of channels can be a problem.

For example in DPNSS you may have A end and B end or X/Y A/X is usualy the CO.

B-Channels wont automatically go into the same state as the CO channels when they are taken down to MANB (Manual Busy), (there are Signalling timers (CCITT/ITU)
Its only when you drop the D-Channel that causes automatic change of states.

In reality the CO wont busy out the channels they should offline them(Offline them/BSY INB in the DMS world.) or remove them from the trunk group. (busy states allows CO's to do diagnostics/changes etc.)BSY INB the Channels at the CO.

Hope this helps.

keep in mind is that at the CO there will be 2 states BSY & BSY INB (or offline). (Try and get them to BSY INB the channels (off line).

 

[glynnmsg]

NYCTECHIE, Did you get this resolved. I had a simalar issue. Where my channels whould lock up I was getting ERR9032. I found a patch on the NORTEL web site mplr 19572. This cured my issues. I have the opt 81 c on 3.0 and the trunks were pri

 

[NYCTechie]

No This is kind of floundering around I'm a consultant and the res tech is the one pursueing this issue...As soon as I get a resolve I will defintely post it.

 

[NYCTechie]

What we did was change the protocol IFC from NI2 to DMS 100 since we're connecting to a DMS 250. This new protocol allows for B-CH maintenance messaging (NI2 didn't) This is what was causing the lockout. We just needed to make sure that the change we wanted to make didn't affect service that would be noticeable to our clients (i.e. losing caller ID).

After we made this change, no more error on the B-CHs have been recorded, and there are no signs of frame loss or slipage (circuits are running clean)