[Asterisk-Users] PRI Advice...

[Eric Wieling]

Michael Crozier wrote:

> On Monday 11 April 2005 12:04 pm, Michael Crozier wrote:
> 
>>>The zaptel drivers are proving quite unstable with this combination.  If
>>>I attempt to rmmod the zap drivers, the machine hangs and is unresponsive
>>>to keyboard input, ping, or sysreq.  Additionally, I attempted to bypass
>>>the Adtran unit using the TE110's to separate the data channels into an
>>>HDLC interface.  I wasn't succesfull, as the HDLC interface triggered
>>>similar "hanging" problems and I never succeeded in getting packets of
>>>the data channels.
>>
>>For what it's worth, I changed to CVS HEAD and the instability problems
>>modprobe'ing the modules seem solved.  ifconfig down'ing an HDLC interface
>>still produce a stack trace and a kernel thread hang, but it is at least
>>sysreq sync'able.
>>
>>My HDLC Abort problems are lessened, but not solved.  We haven't seen the
>>problem in nearly five hours, reaching a new record.
> 
> 
> The HDLC problems were NOT solved or lessened.  However, the telco (after 
> insisting that they had throughly tested the lines) discovered that there was 
> indeed a problem (unbalanced voltages in one of the pairs).  When they fixed 
> this problem, my "HDLC Abort" problem went away completely.
> 
> The lesson I've learned: It's always the telco's fault :-)

MOST of the time, in my experience, HDLC Abort problems are lost data 
caused by something locking interrupts for too long.  As you 
experienced, it can also be caused by line problems.
-- 
Always do right. This will gratify some people and astonish the rest.
Mark Twain