[asterisk-users] Disappearing B-Channels

[Tilghman Lesher]

On Sunday 10 February 2008 01:44:38 Mark Greene wrote:
> In my efforts to solve a mystery of asterisk slowly loosing it's ability to
> take incoming and outgoing calls I set asterisk to restart b-channels every
> 60 seconds hoping I would find something odd after some time.
>
> So now I am looking at the CLI a few hours later and look what happens when
> asterisk restarts the 23 b-channels I have.
>
> pbx1*CLI>
>     -- B-channel 0/19 successfully restarted on span 1
>     -- B-channel 0/21 successfully restarted on span 1
>   == Primary D-Channel on span 1 down
> [Feb 10 01:41:23] WARNING[4102]: chan_zap.c:2401 pri_find_dchan: No
> D-channels available!  Using Primary channel 24 as D-channel anyway!
> [Feb 10 01:41:24] ERROR[4102]: chan_zap.c:8200 zt_pri_error: !! Got S-frame
> while link down
>   == Primary D-Channel on span 1 up
>     -- B-channel 0/19 successfully restarted on span 1
>     -- B-channel 0/21 successfully restarted on span 1
>     -- B-channel 0/23 successfully restarted on span 1
> pbx1*CLI>
>
>
> That's the output while I've been writing this email. Those are TWO
> restarts of the b-channels. Notice I am missing a seizable amount of my 23
> b-channels.
>
> Where are they going?! How do I find out?
>
> I've recompiled my asterisk, zaptel, and libpri to the most recent versions
> but that's made no difference.

You probably have noise on your T1 circuit, which is causing the PRI
signalling to become corrupt.  If this continues, expect that the T1 circuit
will go down from time to time, for a few seconds each time.  Your solution is
to call your telco and ask for a loopback test.

-- 
Tilghman