[Asterisk-Users] Channel bank problem via long cable

Nik Martin nmartin at radiancetech.com
Mon Jun 21 10:17:38 MST 2004


Do you have access to a T-1 analyzer?  You more than likely have a 'dirty'
T-1 line that is out of spec based on the length of the run.

Nik

-----Original Message-----
From: asterisk-users-admin at lists.digium.com
[mailto:asterisk-users-admin at lists.digium.com] On Behalf Of Bonzo Armstrong
Sent: Monday, June 21, 2004 5:43 AM
To: asterisk-users at lists.digium.com
Subject: [Asterisk-Users] Channel bank problem via long cable


I've got a Digium TE405P feeding three Carrier Access AB-II units located in
three separate suites of the complex my company resides in.  I've had one
AB-II connected over about 15' of cable and running for several weeks now,
and it seems to be perfectly happy.

Over the weekend, I added two more AB-IIs, one in each of the other two
suites.  The second unit is about 150 cable feet away from the switch and it
syncs up just fine, but the third is 400 cable feet away and is having
problems with its T1.  The dip switches on all three units are set the same,
and with the exception of the LBO they're all configured the same in
zaptel.conf, yet the furthest AB-II is showing errors.

I've swapped AB-IIs between positions to no effect;  whichever unit is in
the furthest suite cannot fully sync.  There are at least two cables
available in each segment of the run between the far AB-II and the switch
(due to the way our complex is wired, the run is a total of three in-wall
cables and four patch cables), and I have tried them all. I have also tried
plugging into other ports on the TE405P.  I've tried changing the signalling
and the framing.  I've tried changing the LBO value to everything from 0 to
4.  Through all this, the constant appears to be that any AB-II placed 400'
away from the switch will not behave.

When initially connected, the led next to the T1 jack on the AB-II blinks
yellow a few times, then turns green for at most a quarter second and then
to solid yellow where it stays.  The other status led on the AB-II for the
span stays a solid green.  Picking up a phone connected to this unit gets me
a very noisy dialtone.  If I dial a single digit to get rid of the dialtone,
I hear a pretty steady buzzing noise where there should be silence.

The curious thing here is that if I use this phone to dial another
extension, 1) there is no problem dialing and 2) if I use a station that's
working properly to listen to the voicemail message, I hear a perfectly
clear signal with just a hint of that same buzzing in the background.

My zaptel.conf looks like this:

span=1,1,0,d4,ami
span=2,1,0,d4,ami
span=3,1,4,d4,ami
fxoks=1-16
fxoks=17-24
fxoks=25-48
fxoks=49-72

Can anyone tell me what I'm missing or what else I might try?  Thanks in
advance. _______________________________________________
Asterisk-Users mailing list
Asterisk-Users at lists.digium.com
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users





More information about the asterisk-users mailing list