[j-nsp] Strange RX issue w/ GE PIC

[Eric Van Tol]

Hi all,
I'm experiencing a strange RX issue on a link and I need some more ideas on where to look.  Two routers, an M7i and M20, are connected back-to-back, sort-of (there's optical gear between them, obviously), over a WDM link.  Ping tests work perfectly from one to the other, using various packet sizes.  When enabling traffic from the M7i to the M20 by lowering an OSPF metric, the link works fine.  When enabling traffic in the opposite direction, M20 to M7i, I begin to get massive input errors on the M20 GE PIC.  I see no errors at all on the M7i side, ever.  Errors only start to accrue when traffic reaches a certain as-yet-undetermined level, when bi-directional traffic is enabled.

Done so far:
 - Cleaned every connector in the path.
 - Replaced both patch cables at either end of the link.
 - Installed intermediary switch to rule out PIC/SFP problems.
 - Failed over to redundant light path to rule out primary path problems.

In what situation would one see input errors accrue on one side, but only when bi-directional traffic is enabled?

Thanks,
evt