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From: chris@gargoyle.uchicago.edu (Chris Johnston)
Newsgroups: comp.dcom.sys.cisco
Subject: Re: Terminal server hangs
Message-ID: <1991May20.165041.7944@midway.uchicago.edu>
Date: 20 May 91 16:50:41 GMT
References: <35086@boulder.Colorado.EDU>
Sender: news@midway.uchicago.edu (NewsMistress)
Organization: Department of Computer Science
Lines: 43

In article <35086@boulder.Colorado.EDU> you write:
>The problem is that output coming back to dial up terminals through the 
>terminal server will hang for anywhere from 30 seconds to 2 minutes at a 
>time.  
>
>Mike Rackley, Mississippi State University
>Internet: jmr1@CC.MsState.Edu    Bitnet: JMR1@MsState
>Phone:    (601)325-7028          FAX:    (601)325-8921


Hi Mike,

  I'm the guy who had the SQE problem.  However, it was not the
tranceiver on the terminal server.  I turned off SQE on the tranceiver
attached to our multiport hub.

    | | | | | | |
    -----HUB----- 
             | <- disable SQE on "out" side of hub

  A former colleague of mine who still works at U of Chicago disables
SQE on all his tranceivers.

Disabling SQE cleared up the following symptoms on a very small six
node ethernet...
  Character echoing on terminals was falling 8 to 20 characters behind.
  NFS performance between some hosts was poor.
  Remote tape throughput between some hosts was poor (about 30 seconds
per tape block).

  We isolated the problem to one tranceiver by partitioning our
network.

  Can anyone explain why disabling SQE cleared up my problems.

  SQE is sometimes called Heartbeat or Jam.

cj


chris@gargoyle.uchicago.edu 
312-786-4889
I work for a company named AM Investors