[comp.protocols.tcp-ip] SCO TCP/IP SLIP

mpd@anomaly.SBS.COM (Michael P. Deignan) (03/24/91)

jdeitch@jadpc.cts.com (Jim Deitch) writes:

>I have been trying to get a difinitive answer from SCO on this for
>about 5 weeks.  A person at SCO, ericd, told me it was possible to
>have more than one slip.  It was reiterated by paul@bohdan.  He
>supposedly sent a script which let this happen.  The script either
>didn't arrive, or got eaten somewhere.  I fired off a request to
>support@sco.com but have heard nothing but all the machines at sco
>tell me the message was delivered.

Welcome to the club! Only I've been waiting more like *4 MONTHS* for
an answer. What I want to do is:


MACHINE A --> dialup SLIP --\   
                            
MACHINE B --> dialup SLIP ---> SCO XENIX BOX <-- dialup SLIP --> JvNCnet
                            
MACHINE C --> dialup SLIP --/

In other words, I want to allow sub-SLIP sites the capability of
dialup capabilities into an SCO box (sometimes simulatenously) which
will be connected to the Internet via a dialup-SLIP connection.

I asked, to no avail. My question was supposedly referred to the sales
department, but I never heard back.

>Paul, if you are out there, the script didn't arrive. Please send it
>again.
 
I would be interested in seeing this script too.

MD
-- 
--  Michael P. Deignan                      / Since I *OWN* SBS.COM,
--  Domain: mpd@anomaly.sbs.com            /  These Opinions Generally
--    UUCP: ...!uunet!rayssd!anomaly!mpd  /   Represent The Opinion Of
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ronald@robobar.co.uk (Ronald S H Khoo) (03/28/91)

mpd@anomaly.SBS.COM (Michael P. Deignan) writes:

> What I want to do is:
> 
> MACHINE A --> dialup SLIP --\   
>                             
> MACHINE B --> dialup SLIP ---> SCO XENIX BOX <-- dialup SLIP --> JvNCnet
>                             
> MACHINE C --> dialup SLIP --/

I strongly urge you to reconsider this.  Xenix/Unix is not designed to
be particularly efficient as a comms box OS, and thus, you will render
that poor ole' xenix box in the middle unuseable for anything.  In terms
of context switches alone, its CPU will be swamped.  Consider instead:

MACHINE A --> dialup PPP/SLIP --\   
                            
MACHINE B --> dialup PPP/SLIP ---> PC running KA9Q <-- dialup SLIP --> JvNCnet
                                          |
MACHINE C --> dialup PPP/SLIP --/         | ethernet
                                          |
				     SCO Xenix Box

(you may wish to put the SLIP out to JvNCnet on the Xenix box to get
 better policy control, etc, but I would try not to.  Running no SLIP
 at all on the Xenix box makes it much more reliable.)

which costs you an extra two ethernet cards and a PC, + (say) an AST 4
port card ($100 approx, + you'll need to buy 4 x16550AN UARTS if you're
expecting to do high speed stuff) However, you will also be able to use
your Xenix box (ie get some value out of that unix license and support
co$ts :-( ) and of course save on the probably more expensive intelligent
serial ports on the Xenix box -- running SLIP on a dumb serial port on
Xenix is a non-starter above 1200 or 2400 or so.

Also, you'll have the adcantage of being able to run PPP
instead of SLIP which is *much* more reliable and has inherent in the
protocol support for authentication and ip address allocation.  Also,
you'll suffer almost none of the nasty surprises like corrupt UDP
packets which plague SLIP.

Remember: every single character that arrives on a Xenix box for SLIP
goes in the kernel, out to user space to the slip daemon, back in again,
causing the poor old 386 to have a heart attack.

This is the reason why people use routers, and a PC (say a cheap 286
motherboard with 512K ram + 1 floppy disc) makes an effective solution.
-- 
Ronald Khoo <ronald@robobar.co.uk> +44 81 991 1142 (O) +44 71 229 7741 (H)

mpd@anomaly.SBS.COM (Michael P. Deignan) (03/31/91)

In comp.protocols.tcp-ip you write:

>I strongly urge you to reconsider this.  Xenix/Unix is not designed to
>be particularly efficient as a comms box OS, and thus, you will render
>that poor ole' xenix box in the middle unuseable for anything.  In terms
>of context switches alone, its CPU will be swamped.  Consider instead:

{suggestion list deleted...}

Sounds like good suggestions. Good thing I'm not planning on "expansion"
until later on down the line. Right now, I'm only working on implementing

	SCO XENIX --> dialup SLIP --> JvNCnet

Of course, It would be preferable to just run an Ethernet connection to
JvNCnet, unfortunately my measly paycheck won't allow the costs associated
with that type of connection.

MD
-- 
--  Michael P. Deignan                      / Since I *OWN* SBS.COM,
--  Domain: mpd@anomaly.sbs.com            /  These Opinions Generally
--    UUCP: ...!uunet!rayssd!anomaly!mpd  /   Represent The Opinions Of
-- Telebit: +1 401 455 0347              /    My Company...
-- 
--  Michael P. Deignan                      / Since I *OWN* SBS.COM,
--  Domain: mpd@anomaly.sbs.com            /  These Opinions Generally
--    UUCP: ...!uunet!rayssd!anomaly!mpd  /   Represent The Opinions Of
-- Telebit: +1 401 455 0347              /    My Company...