[HECnet] DECnet performance problems (on TOPS-10)

[gerry77 at mail.com]

Dear All,

I'm in need of some suggestions to improve DECnet performance of a TOPS-10
monitor running on KLH10. I'd like a lot to hear from you even if you do not
know or run that specific system or configuration.

When used locally at the CTY (Console terminal), the system response is very
fast and smooth, so I'd tend to exclude emulator problems and such. Instead,
when used from a remotely connected terminal (e.g. from VMS via SET HOST),
it appears very sluggish: single character echo is very poor and output from
the system fits and starts all the time. Output from programs is very fast
for some hundreds lines, then stops briefly, then again appears almost
instantly, and so on, like in bursts.

Anyway, while the overall bulk data performance can be considered absolutely
acceptable, the char-by-char responsiveness, e.g. typing interactive
commands at the monitor prompt, is horrible: I type "D", "I", "R", and
nothing happens, then I type "E" and "DIRE" suddenly appears...

The TOPS-10 system has plenty of free core (both virtual and physical), free
disk space, and free CPU, so it shouldn't be an OS issue in itself.

Probably the most likely cause of this problem lies in some DECnet parameter
that needs some tweaking, but I do not know which one... Have you ever had
any experience with some ancient Digital OS having poor DECnet performance
as described? And how did you solve that, or at least improve it?

Here are some (maybe) interesting bits:

Request # 1; Show Executor Node Characteristics Completed

Executor Node = 1.1010 (DIECI)

  Identification = DECnet-10 Version 4.0
  Management Version = 4.0.0
  Loop Count = 1
  Loop Length = 127
  Loop With = Mixed
  Incoming Timer = 30
  Outgoing Timer = 60
  NSP Version = 4.0.0
  Maximum Links = 65535
  Delay Factor = 48
  Delay Weight = 10
  Inactivity Timer = 120
  Retransmit Factor = 10
  Routing Version = 2.0.0
  Type = Nonrouting IV
  Routing Timer = 600
  Broadcast Routing Timer = 40
  Maximum Address = 1023
  Maximum Circuits = 20
  Maximum Cost = 100
  Maximum Hops = 16
  Maximum Visits = 20
  Maximum Broadcast Nonrouters = 64
  Maximum Broadcast Routers = 32
  Maximum Buffers = 80
  Buffer Size = 576
  Segment Buffer Size = 576

Request # 5; Show Line Characteristics Completed

Line = ETH-0

  Receive Buffers = 6
  Controller = Normal
  Protocol = Ethernet
  Hardware Address = AA 00 04 00 F2 07
  Receive buffer size = 576

Request # 7; Show Circuit Characteristics Completed

Circuit = ETH-0

  Cost = 1
  Maximum Routers = 16
  Router Priority = 5
  Hello Timer = 90
  Type = Ethernet

I'll be grateful for any suggestion! :)
G.