[c-nsp] Two DS3s Bounced at the Same Time

[Rodney Dunn]

Possibly.  I learned more than I wanted to know about
L1 stuff working on that bug.

I can tell you it's important that ALL devices along
the L1 path adhere to those specs correctly or you
can spend a lot of time troubleshooting one component
when another is at fault too.

ie: For the particular customer I worked on that bug
with the interfaces were flapping along with the T3 controller
bouncing.  It turned out to be a bug in the remote CSU/DSU
too where it was sending AIS too soon and when the T1 framer
on the headend got AIS it brought the T1's down immediately
as it should.  That was independent of the T3 bouncing
incorrectly.

Analyzers on the line usually tell the truth.  That's what
I learned on that one...

Rodney


On Mon, Mar 21, 2005 at 08:26:53AM -0700, John Neiberger wrote:
> >>>> Rodney Dunn <rodunn at cisco.com> 3/20/05 5:40:56 PM >>>
> >All it takes is a switchover of some sort in the
> >transport path to send an alarm down the circuit
> >and the T3 will go down and come right back up within
> >a second or so.
> 
> I heard from one Qwest technician that there had been some sort of
> issue with our OC12, perhaps a capacity problem on the OC48 that it was
> riding. I was told that it had been repointed or redirected somehow but
> this particular tech didn't have any details. I wonder if that was what
> triggered an LOS or AIS which in turn caused this bug to rear its head.
> 
> I'll call Qwest again this morning and see if I can find out more info
> about that.
> 
> Thanks!
> John
> --