🚀 go-pugleaf

I am having problems in a large but not excessive Ethernet consisting
of a variety of cabling systems from twisted pair to optical, and equipment
from UB, DEC and BICC. Protocols include TCP/IP and DECnet.

VAX based terminal servers with CMC ENP55 Ethernet cards seem to be
resetting as queues overflow. The net is not particulary heavily loaded,
but when we did a stress test on the network, we noticed a number of 'late
collisions'.

If everything is OK, late collisions shouldn't happen. I have never seen
this happen before, but I have never looked for them. We seem to have about
1 error in 10,000 packets, even if we strip the network to a minimum.

1)  Is this a high level, or is it acceptable ?
2)  Has anyone had similar experience, especially with this card ?
3)  Does anyone have any idea how a card will (in general) react to
    this (illegal) condition.
4)  Any advice as to how I should track down the cause, rather than
    trying to attack the symptoms.


Keith Dixon.