[Asterisk-Users] D Channel Becoming "CORRUPTED"?

[Damon Estep]

> 
> Hi,
>     This is not entirely an asterisk question but I figure someone
> here may know the answer to this question.
>     On several occassions we will lose the ability to use one of our
> PRI lines.... well for our phone system anyway.... (we also sometimes
> lose PRIs on some of our access equipment, etc).   After much trouble
> shooting I finally decide to reset the PRI (unplug it and plug it back
> in).  This seems to fix the issue... both on the * server, as well as
> on our Cisco access equipment.
>     The explination the phone company has given is that perhaps the "D
> channel is becoming corrupted and needed to be reset".  This sounds
> like a cop-out to me.  Any thoughts?   Shouldn't I be able to expect
> my PRI lines to run 100% without the need for a line reset?

My experience has been that a provider will not fix a problematic DS1
until you identify (or help hem identify) an error condition on the
line.

The problems you describe are most likely caused by a high bit error
rate on the lines.

With very high bit error rates a device can lose sync with the line.

Make sure you do not have configuration errors on your equipment,
because the line does work at times, It is safe to assume you are
configured at least partially correct, but make sure you pay close
attention to where you are getting your timing from. In most cases a CPE
device should use the "line" for timing.

Call your Telco and tell them you would like to have at monitor placed
on all of your T1s for a couple of days with a report of the bit error
rate given to you at the end of the monitoring window.

Ask them up front what an acceptable bit error rate is and hold them to
it.

You did not specify what card you terminate the * PRI with, but the
Cisco device should have counters where you can see the error counts,
try show interface and show controller in the privileged exec mode on
the Cisco CLI.