Sun-3 communication with Xerox using Ethernet ?

[mats at enea.UUCP]

I'm looking for a way to connect Sun-3 workstations with 
Xerox (Big Ben) workstations using Ethernet.  The main
requirement is to be able to transfer files, but the need
for more functionality will surely arise when people 
start using the systems.

My understanding is that there is compatibility at the
hardware level but they use different protocols (TCP/IP
vs. XNS).  There seems to be at least three solutions
to my problem.

1. Get XNS for the Sun systems.  I know there is (limited)
   XNS support in the BSD 4.3 distribution for the VAX.
   Does anyone know if Sun is going to support XNS in any
   future release of their os?  The Sun's that I have looked
   at are 4.2 based and I couldn't find any references to
   XNS in the documentation or elsewhere. We are BSD 4.3 
   source licensees,  but I can't afford to try a port myself.

2. Get TCP/IP for the Xerox machines. I have a (slightly 
   outdated) version of the "TCP/IP vendors and implementations
   guide" but there is no mention of any Xerox hardware or
   software in it.

3. Get some sort of gateway/bridge which will do the conversion
   between TCP/IP and XNS,  possibly using different LAN's.
   This seems to be a really ugly solution.

Has anyone done anything like this before?  Any help would
be appreciated.  I might add that we're perfectly willing to
pay a reasonable price for a useful product.
-- 
Mats Josefsson, ENEA DATA, Sweden

UUCP: {seismo,mcvax,munnari,cernvax,diku,inria,prlb2,penet,ukc,unido}!enea!mats
Internet: mats at enea.se