[j-nsp] 4CHDS3 and M40, T1 interfaces won't come up

[James Sneeringer]

On Mon, Jul 05, 2004 at 04:34:57PM -0500, James Sneeringer wrote:
> hardware: M40, P-4CHDS3
> software: JunOS 4.4R3.4

Problem possibly solved.

This has been an ongoing problem, so our vendor shipped us a replacement
FPC and 4CHDS3 PIC, just in case it turned out to be a hardware problem.
We swapped out the FPC and PIC, with no change in behavior.  We then
installed the old FPC and PIC in a different slot and moved the DS3 to
the old PIC in the new slot, and T1 channels now come up.

I'm left to ponder the following possible causes of the original problem.

1) The system simply didn't like the 4CHDS3 card being positioned at 4/3,
   perhaps because it shared the FPC with other cards?  It also has a
   4FE-Tx at 4/1 and a 4DS3 at 4/2.  This was how our vendor configured
   it prior to shipping.

2) There's some hardware problem with slot 4, such that whatever PIC is
   in position 4/3 will have communication problems.

3) Undiagnosed (or misdiagnosed) bug in our EOL'd version of JunOS.

4) Sun spots?  Ghost in the machine?

Coming from the Cisco world, I've grown accustomed to not being able to
use certain combinations of cards in certain slots (e.g. "bandwith
points" on the 7200VXR series).  Does the M40 have such a notion?
Perhaps I just can't put a 4DS3 and a 4CHDS3 in the same slot?

If anyone has any ideas on this, I'd be happy to hear them.  It appears
to be functioning properly now, I just wish I knew why it wasn't before.

-James