telnet/PC-NFS, bad performance

[M_Kooij at pttrnl.nl]

We experience the following (rather severe) performance problem with
telnet used from a pc (with sun's PC-NFS 3.0.1).

Every now (and then :-) ) telnet keeps characters for itself on the PC for
about 5 seconds. It looks like the host one is working on is heavily
loaded. However in practice the host is almost idle (we do not have very
high workloads here, 1 is about the maximum).

Tracing the problem with etherfind shows however that the reaction of the
host is very fast, but the characters stay on the PC for a long while.

The reason I post this to the sun group is three-fold

- I am experiencing the same problem with other telnet servers but much
  less reproducibly.
- I seem to remember that it is a known problem. Is there some solution?
- The problems have *worsened* badly since the addition of a sun 4/490
  server, making access to all computers in the network slower. Can anybody
  explain this?

More problems:

Considering the fact that the 4/490 is blindingly fast, I wonder why
doing a directory listing from a PC of a remote mounted disk is so slow,
and also the reverse arp procedure NET RDR on the PC's when doing booting
is so slow. Anybody knows? Did I make some obvious error?

Some information:
   configuration:
      6 SUN 3/60 
      1 SUN 4/490
      ca 20, soon 50 PC's with PC-NFS, and micom NI5210 interface card.
      a 1 segment ethernet, load average 8%, peak 16% to 20%
   software:
      SUN OS 4.0.3 (on all SUN's)
      PC-NFS 3.0.1 (on the PC's)

Please reply to my domain address (pttrnl in the nl domain), below.

Martin Kooij @ PTT Research Neher Laboratories
mail: P.O. Box 421. 2260 AK  Leidschendam, The Netherlands
tel : +31 70 332 5441
email:M_Kooij at pttrnl.nl  'Formally I insist on the intuitive meaning'