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Path: utzoo!attcan!uunet!samsung!gem.mps.ohio-state.edu!pacific.mps.ohio-state.edu!verber
From: verber@pacific.mps.ohio-state.edu (Mark A. Verber)
Newsgroups: comp.protocols.tcp-ip,comp.protocols.tcp-ip.ibmpc
Subject: Re: How fast is SLIP?
Message-ID: <1093@pacific.mps.ohio-state.edu>
Date: 21 Nov 89 05:12:58 GMT
References: <5968@cbnewsh.ATT.COM> <5969@cbnewsh.ATT.COM>
Reply-To: verber@pacific.mps.ohio-state.edu (Mark A. Verber)
Followup-To: comp.protocols.tcp-ip
Organization: Ohio State University, Physics Department
Lines: 55

In article <5969@cbnewsh.ATT.COM> wcs@cbnewsh.ATT.COM (Bill Stewart 201-949-0705 ho95c.att.com!wcs) writes:
>We have several locations with Ethernets and Suns, connected by a Datakit
>network that can give us good async connectivity, and we'd like to
>bridge or route the Suns together.  While there are some respectable
>solutions to the problem, all of them require capital budget and time,
>and we'd like to get something working quickly, performance not critical.
>

You might want to check around.  There was a tcp on top of datakit
(don't shoot) done in the mid-80s.  The version I saw ran on BSD 4.2
Vaxen with DataKit, but it believe it was built on other systems.  You
might also have real Internet access shortly.  I know that there is a
project to get Internet connectivity improved throughout the Labs.  If
you are real interested, I can check will some friends for more info.

>The obvious approach seems to be SLIP - we can nail up a 19200 baud
>connection across the Datakit and snarf the software off uunet,
>using our file server as a router, and maybe also use some of the spare
>PCs lying around with pcbridge or pcroute.  RFC 1055 talks about
>future header compression work - is this available yet, or does
>uunet have the latest stuff?

You could run SLIP over DataKit.  I am not clear why you would need the
IBM-PCs.  You could run SLIP under SunOS 3.5 and not worry about
the IBM-PCs.  The header compression (actually prediction) has not
be release yet (Hello Van?).  It should be out soon (we all hope).

>How much CPU does this use?  Will it use up half the CPU (bad) or
><10% (ideal)?  We're mostly running Sun 3/150s with SunOS 3.5,
>though the server may get upgraded to 4.0.X, and we have
>ALM-2 boards as well as the built-in ports.  Can the Sun handle
>19200, or just 9600?

CPU usage shouldn't be too bad.  The worst I have ever seen was about 5%.
I personally find the ALM-2 objectional, but there are patches from
Uof Toronto which make the ALM-2s usable for fast SLIP.  I have used
SLIP at 19.2K will the patches successfully,

>
>Is more than one line possible on a single machine?
>Aside from horsepower problems, will the software support it?
>This is especially a concern for the pc products.
>
>Also, does Wollongong support SLIP in a compatible fashion?
>We have a few 3B2/300s which aren't very busy.
>-- 
You can have more that one line if the software supports it.  KA9Q supports
multiple lines, I am not sure about pcroute, but I think not.  All the
Unix based versions of SLIP that I have seen support multiple SLIP
connections.  Wollongong does support a compatible SLIP.
-- 
Mark A. Verber
System Programmer, Physics Department, Ohio State University
verber@pacific.mps.ohio-state.edu
(614) 292-8002