SLIP for XENIX?

[Lance_C_Norskog at cup.portal.com]

Yes, Streamlined Networks has a TCP/IP implementation which supports
SL/IP for XENIX/386.  SL/IP by itself is just a network medium,
like Ethernet or X.25 (which are also supported).  The SL/IP support
is piggybacked onto existing serial/tty software: you change the
line discipline of any serial line and SL/IP latches onto it.
When you kill the SL/IP control program, or the modem hangs up,
SL/IP lets go and the serial line is back to normal operation.
So, if you can make it run UUCP and CU reliably, you can run SL/IP over it.

Streamlined TCP is a (very pure) port of BSD 4.3-tahoe, and the socket
libs et. al. work on it.  

Lance Norskog
Sales Engineer
Streamlined Networks
415-659-1450