atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's t1 timing issue

it's an internal csu.

although asterisk has the capability to use voip, we're not using it for outbound calling. the pc has a t1 card that the interfaces with the smart jack similar to most digital phone systems from what i understand.

here is a snippet of the latest log. today has been an absolute nightmare as far as the drops go.

100 05/27/2009 10:35 AM NOTICE chan_zap.c: PRI got event: No more alarm (5) on Primary D-channel of span 2
101 05/27/2009 10:35 AM WARNING chan_zap.c: No D-channels available! Using Primary channel 48 as D-channel anyway!
102 05/27/2009 10:35 AM NOTICE chan_zap.c: PRI got event: Alarm (4) on Primary D-channel of span 2
103 05/27/2009 10:35 AM WARNING chan_zap.c: Unable to disable echo cancellation on channel 47
104 05/27/2009 10:35 AM WARNING chan_zap.c: Detected alarm on channel 47: Red Alarm
105 05/27/2009 10:35 AM WARNING chan_zap.c: Unable to disable echo cancellation on channel 46
106 05/27/2009 10:35 AM WARNING chan_zap.c: Detected alarm on channel 46: Red Alarm

Maybe I'm looking at this wrong (and maybe it could be just an "Asterisk" thing) but the error logs clearly identify a "Primary D-Channel" of "span 1", and also a "Primary D-Channel" of "span 2". I also notice 46 "B-channels" throughout the error logs, which tells me that your system is configured for at least two PRIs.

Is this correct?

Were you receiving these "No D-channel Available" warnings before you "restarted" the system?

sorry for the confusion. we only have one pri but the t1 card that we use actually has two ports. last night after digium tested the card we decided to plug the t1 into the second span to see if it would make a difference. it obviously hasn't so we will be moving it back soon.

regarding your question about d-channel available warnings. we were still getting them before we rebooted the server as well.

If possible, can you post any new errors after moving the T1 back to the original port?

sure will. we haven't had a problem for a couple of hours so i've been holding off on making the switch but i will do it after the office closes it and will post the log after the next red alarm.

att is currently running intrusive tests on the circuit which is not allowing me to get an accurate log. they want to do a class a cable inspection but they said that they will charge us $1500 every four hours if they do not find any issues. is this normal?

also, should they be able to detect every red alarm that we see if they are monitoring the circuit?

Not know which at&t local or ld hard to say. They won't see alarm history in the at&t stuff but they will see a history of oof's when the circuit went down. Also depends what equipment they are looking at. I'm talking from the LD side. The charging sounds like you dealing with at&t local service.

verizon is actually our local telco but our t1 is thru att.

Well at&t used to terminate in 4E's for pri, not sure about now. They should have places to monitor and if you're getting red alarm on the T1, which I don't know if you are or not, they will have an alarm history of yellow at the 4E, unless it's failing both ways. Not knowing the circuit layout or what's on it it's really hard to say. If it's failing in the local access and they can't see alarm history they would have no information. Hopefully a stress test will find it if it's in the access.

well i just heard from att and they found a problem. they're not telling me what it is as verizon has not released it to them but they schedule to dispatch someone tomorrow morning. i guess we'll have to wait and see. i just hope they don't start blaming the pbx again.