[c-nsp] ATM Issues

[clayton at mnsi.net]

I've been having a strange packet loss issue on an ATM connection between 2 Cisco
routers (NPE-G1 and a 7301).

Both routers are acting as bridges (ATM Subinterface sits in the same bridge group as a
GigE Sub Interface).

For some strange reason, I get occasional packet loss, particularly during periods of
higher (30 meg or so) activity.  The PVC is set in the carrier's network for 100 Meg
UBR service.

I understand that the carrier may drop cells due to the class of service we're using,
but the funny part is that I can't see any AAL5 errors on the PVC.

I would expect that if the carrier is dropping cells, we'd see the AAL5 error counters
increment.

What should I be looking to as the cause of the packet loss?  Since I don't see AAL5
errors, I'm starting to suspect something other than the ATM carrier's network.