From: rcosby@bcm.tmc.edu (Randy C. Cosby)
Newsgroups: bit.listserv.novell
Subject: Re: Performance issue of ethernet
Summary: Re: Performance issue of ethernet
Date: 27 Jan 93 15:11:16 GMT
Organization: Baylor College of Medicine, Houston, Tx
NNTP-Posting-Host: bcm.tmc.edu

In article <NOVELL%93012703453643@SUVM.SYR.EDU>,         Sanjay Patel <074SAN@WITSVMA.WITS.AC.ZA> writes:
> What I  would like to know is the following
> (1) what is the maximum amount of workstaions that you could hang of a 10baseT
>     ethernet segment before performance starts decresing and bridges etc need
>     to be introduced
>     I need to run 70 workstations . Will this be possible? if so what are the
>     performance issues?
>  (2)How will an application like DBASE perform with all workstation running
>     and each creating its own database and working on it?
>  (3)How will a superserver like a NETFRAME perform if it were to do all the
>     bridging i.e 2 ethernet segments and 1 tokenring segment coming of it
>     Currently I have 2 ethernet servers and 1 token ring server each forming it
>     own network and all 3 being briged by a router running ROUTER.EXE with 3
>     cards in it. The performce for this setup is slow especially when I run
>     an I/O intensive application like DBASE.
> *************************************************************

Sanjay,

I can only speak from an Ethernet standpoint, thus I will formulate
answers to 1, 2, and 3.

I have at least one segment running more than 70 workstations. They
are running on a 3Com/Synoptics 3000 series concentrator.  I have
very few performance problems on these segments.  If problems exist
they can usually be traced to bad cabling.  
My Pharmacy is running on a segment with around 75 workstations on
the segment with the file server.  It runs fine and is very 
i/o intensive. It uses software that runs interpretive Revelation.
The Bridge issue almost an experimental/trial and error one.
I have bridges in areas I found needed them.  Most of my bridging
is done on the backplanes of 3Com Netbuilder II's running six
ethernet bridged ports and one FDDI.  This is very efficient.

I think placing two ethernet cards in a file server is going to
cause you problems, unless by using the Novell bridging stuff
you have a local segment and the other to a "campus" segement.

Remember, every bridge you introduce on to your backbone will
effect the spanning tree algorithm.  If you place two NIC's
in the server, you will have to attach them to separate concentrators
or repeaters or backbones to really get any more throughput no 
matter what kind of server platform.

Try separating the routing function to a true bridge/router. 
I, of course, reccomend 3Com bridge/routers. The performance
advantage of a real brouter vs. a p.c. running software is
significant!

We are currently running our Payroll dbase server using Novell
and many workstations access it.  Depending on the protocol
running you may or may not have luck. Ours is running NetBios,
it is not efficient!  We have slow response at times and using
a Network General Sniffer I found that workstations were waiting
on the dbase server and/or NetBios.

Good Luck,


Randy Cosby
Network Manager
Texas Children's Hospital
Houston, Texas
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