[Asterisk-Users] its all 6's and 8's?

[Storer, Darren]

On Tue, 5 Oct 2004 15:38:12 -0500, Brian West <brian at bkw.org> wrote:
> How often do you guys see Event 6 and 8 on your PRI?
> (aka "HDLC Abort" and "HDLC Bad FCS")
> 
> Is this normal?  I would think not.
> 

Hi Brian,

seems to depend what sort of switch the Asterisk node is connected to
and over what sort of connection.

You will see occasional transmission hits if you are connected to a
Nortel DMS when the REX (Routine EXercises) are running and the D
channel is switched from X to Y (or the reverse) but that would
account for a hit every 2/3 weeks depending on the size of the switch
and the REX schedule (usually after 01:30 when everything is quiet). 
The same kind of effect can be observed on Marconi System X switches
using SS7 signalling when change overs occurr, sometimes twice a day,
not pleasant stuff to watch all the GLKs bounce...

Apart from switch change overs the production systems in our customers
show very few event 6/8 messages unless cabling is dodgy (one
co-located server suffered this problem when the Telco had a poorly
patched connection on the frame). Systems that have been running since
the beginning of this year show less than 1/2 dozen events after the
initial cabling has been proven.

Something similar was noted with the new SS7 stack for Asterisk when
the load was high and although the initial suspicion was related to
interrupt priorities I believe that the solution was found in
software.

HTH

Darren
-- 
Darren Storer
Comgate
Telco>Internet<Broadcast