sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's Adtran Smart 16

We have an Adtran Smart 16 Cabinent with 6 T1-esf-csu card modules installed . On all 6 modules the CV leds light at the same time then turn off on the network side . They are turning off and on about once every minute . I was at this site last Friday and it was not happening . Any thoughts on the cause . Thanks :shrug:

The CV LED indicates a code violation. In ESF mode this means either a CRC error or a bi-polar violation (BPV). In SF mode it means a BPV but not a CRC.

I'd start by seeing what the equipment shows under the performance monitoring screen. You should be able to look at 15 minute intervals as well as 24 hour intervals. There may be a T1 level issue.

I'd say check your TX LBO settings under the network options menu to make sure you have the distance from the Adtran to the NIU's correct. You might also check the RX Sensitivity. If you are running a B8ZS circuit, make sure bit stuffing is set to disabled.

It may also be one of those undocumented features (that's a bug) that happens from time to time. We have Adtran TA-1500 channelbanks that can provide 96 pots lines, and sometimes the individual port LED's go on and off even though the subscriber is not.

Yeah…. What Kyle said!!!

I’d also agree the T1 would be the first place to look. With the nature of the “on then off then on” nature of CV’s (code violations) toward the network, I’d be inclined to think you have T1 issues with clock/timing slips.

Thanks,
Bryan
Cars –n- Guitars Racin’

Yeah it's strange that all 6 PTP T1's are doing The exact same thing . I think I will drive back to site a verify the cards are programmed like the ones in our building . I did check the DT stats on the PBX'S local and remote and no errors are be logged except an occasional retransmit error .

Checked the programming on the host site with cv leds flashing on and off . It's identical to what is programmed in our Adtran Smart 16 modules . I think in the AM I will have SBC check for CRC errors . Since it's on the Network side . These circuits have been working ok for years . It's not causing any issues as no trouble reports have been opened from the host or remote sites . :shrug:

Whuh???

Well, just don’t fix it ‘til it’s broke then. This may be a case for 6 small pieces of electrical tape and a swift silent retreat.
:toothy:

Yep did that one time to a phone that the woman complained the message light was too bright . She would rather complain then listen to and save/delete messages . But I used scotch tape . "Trouble" is gone now . SBC made some design changes to the wrong group of circuits , imagine that ! That's their story and they are sticking to it .