*Serious* ethernet constipation (not tu0 related)

From: Ray Bellis <Ray.Bellis_at_psy.ox.ac.uk>
Date: Wed, 17 May 95 09:10:04 +0100

We have a network here comprising of twenty thin wire segments attached
together via an Isolan multiport repeater. Communication between
Alphas on the same segment is fine (1100 kb/s) but communication
between Alphas on different segments is dreadful (15 kb/s). What's
also strange is that one set of Alphas are behind a different segment but
behind a bridge. FTP transfers to those Alphas run at around 100 kb/s.
Transfers between Suns and Alphas on different segments always run faster
than transfers between Alphas on different segments.

Maybe a picture would show it best:



                           +---------------+
                           | Isolan |
                           | repeater |
                           +--+-+-...-+-+--+
                              | | . . | |
                              | | . . | |
                             / | | \
              ______________/ | | \____________
             / _____/ \______ \
            | / \ |
            | | | *--(AXP 4)
            | | | |
   (AXP 1)--* *--(AXP 8) * +---+---+
   (AXP 2)--* *--(SUN 2) * | bridge|
   (AXP 3)--* | | +---+---+
   (SUN 1)--* - - |
            | *--(AXP 5)
            - *--(AXP 6)
                                                        *--(AXP 7)
                                                        |
                                                        -

  axp1 <--> axp2 : 1100 kb/s
  axp1 <--> axp4 : 15 kb/s **
  axp1 <--> axp5 : 100 kb/s **

  sun1 <--> axp4 : 330 kb/s
  sun1 <--> axp5 : 230 kb/s

Does anyone have any idea what could cause this? Are the Alphas putting
out packets so fast that the multiport repeated can't handle it (and if
so, how can I slow them down).

Thanks,

Ray
Received on Wed May 17 1995 - 04:13:16 NZST

This archive was generated by hypermail 2.4.0 : Wed Nov 08 2023 - 11:53:45 NZDT