Two Questions

[Keith Moore]

In article <9011031505.AA06211 at anomaly.sbs.com> mpd at anomaly.sbs.com (Michael P. Deignan) writes:
>We're  in the process of getting an Alternet connection. We would like to
>network multiple Xenix boxes off the main system which is tied in via a
>56kbps TCP/IP line. These connections will be SLIP connections. However, 
>I've heard that you can't run more than 1 SLIP connection at a time. What
>I want to do is as follows:  
>
>
>	box 1 <--- SLIP ---\
>	box 2 <--- SLIP ---|----> main system <--- TCP/IP ---> ALTERNET
>	box 3 <--- SLIP ---/
>
>SLIP connections would be 9600baud, with the TCP/IP connection a 56kbps
>connection.
>
>Eventually, as well, I'd like to be able to run SLIP connections off one
>of the "leaf sites" (ie: box3).
>
>Can this be done with the SCO TCP/IP system for XENIX? What other limitations
>are there?
>
>MD
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You don't want to do this if you want to use your "main system" for anything
else.  The reason is, SLIP connections *eat* interrupts like mad.  Unless
you have some really smart serial interface that knows about SLIP framing
and only interrupts when a frame is complete, you don't want to have three
SLIP connections hanging off a poor Xenix box.

If the cost of Ethernet is prohibitive, consider getting a cheap AT clone
and running pcroute on it (which is free).  You don't even need a monitor!
Use the pcroute box as your gateway system between alternet and your local 
network.   A reasonably fast AT running pcroute should be able to keep up 
with three or four SLIP links without dropping too many packets.

Keith Moore / U.Tenn CS Dept / 107 Ayres Hall / Knoxville TN  37996-1301
Internet: moore at cs.utk.edu      BITNET: moore at utkvx
``Paranoia is a drug which is more dangerous than any controlled substance.''