On 7/19/2018 10:34 PM, Mark Pizzolato wrote:
The improvement by setting the port speed to 10Mbit suggests
that packet loss/overruns are happening and they are reduced
by limiting the wire speed.

Agreed, though nothing ever indicated any errors or overruns: not the switch, not NCP or LANCP on any nodes.

The arrival of DECnet's traffic might be causing a burst of traffic
that still ends up overrunning another systems ability to receive
it.  Do things change if you throttle the simh VAX down?

       sim> SET CPU NOIDLE
       sim> SET THROTTLE 25%

Wow. That was a flashback to 1987, when I was working on a VAX 11/730 with four other developers at the same time. ;-) We all got lots of pleasure-reading done waiting for product builds....

Continued this morning: I ended up going to bed, it was taking so long. I woke this morning to find that the startup took about four hours to complete, and it had spent the next three hours losing and re-establishing communications every 40 seconds. I'm guessing the system was /so/ slow that it didn't respond fast enough to suit the other members.

So I took it down again and did SET THROTTLE 80%.  Still considerably slower, but workable. And as soon as DECnet started, it lost communication and re-established it. It's now two minutes farther into the boot with no further drops.

It drops between the "Starting DECnet" OPCOM message and the first "adjacency up" OPCOM message. After that, all is well.

Thanks.

Hunter


_______________________________________________
Simh mailing list
Simh@trailing-edge.com
http://mailman.trailing-edge.com/mailman/listinfo/simh

Reply via email to