[Asterisk-Users] TE410P ERRORS under load

[Scott Stingel]

Hi all-

HELP!

This is actually a revisit of a problem that I had earlier with E400P's at a
customer site.  Customer still gets locked up channel problem, but has
learned to live with it  (channels clear themselves after several minutes).
The symptoms, which I  believe are directly related:

I'm having problems with tons of framing and "read" errors on my E1
connections (and occasional stuck channels) when I run a very simple IVR
script under anything other than light load.  Previously, I had thought this
problem related to my customer's PBX connections (Nortel DMS100), but in the
last week I've had the opportunity to work in-house with a couple of
TE410P's, with one span making calls to another on the same machine.

I have two simple scripts running under the dialplan.  On span 1, I simply
answer each call, play a short message, and hang up.  On span 2, I run a
Perl script that formats and drops calls (into /var/spool/asterisk/outgoing)
for all channels at staggered times.  These calls are simple outgoing calls
that dial a number, wait 2 seconds, and hangup.  After a few seconds, each
call repeats.

I can run this scenario on up to 10 channels at once with *no errors*.
Above 10 channels, I start to get many (several per second when running 30
channels) framing and "read" errors, with text similar to the following:

WARNING[1167272128]: File chan_zap.c, Line 5670 (zt_pri_error): PRI: !! Got
reject for frame 26, retransmitting frame 26 now, up_dating n_r!
(repeating for each error several times, with ascending retransmitted frame
numbers)

and also, less often:
WARNING[1167272128]: File chan_zap.c, Line 5670 (zt_pri_error): PRI: Read on
NN failed: Unknown error 500   (NN is the channel)

MY SETUP:
Tyan S2723, with dual Xeon's running at 2.4 GHz, 1MB memory
Redhat 9
Two TE410P's, spans set for E1.  Problem happens between spans on different
boards, or spans on the same board.
Sending board setup in zaptel.conf, for example:  span=2,1,0,ccs,hdb3
(adding crc4 makes no difference)
Recving board setup in zaptel.conf, for example:  span=1,0,0,ccs,hdb3   "  "

In zapata.conf, sender is "pri_net" and receiver is "pri_cpe"

QUESTIONS:
ANYONE: Has anyone else experienced these framing problems in any scenario,
and if so, what did you do about it please?

FOR THE ISDN GURU's: What exactly does the framing error indicate? 

THANKS IN ADVANCE FOR HELPING ME SOLVE THIS LOAD_RELATED PROBLEM.

Scott M. Stingel 
Emerging Voice Technology Inc.
Palo Alto, California and London, England
 
URL:            www.evtmedia.com