4.1C/4.2 over broadband using RF modems - how??

[alison at cornell.UUCP]

   We are interested in establishing a point-to-point link as part
of a local network using part of a broadband cable (which also has Sytek
equipment attached) and RF modems.  This would be a long-distance hop
between local Ethernets.
   We think we want to use a synchronous interface (DMC-11??) in the VAX 750
at one end, talking to the RF Modem, and the same in the VAX 750 on the
other end.  Does anyone have experience talking to RF modems?  Does
anyone have advice on what RF modems are suitable?
   We have an additional problem in that the RF modem may be quite some
distance (say 500 feet) from the VAX.  Does anyone have any idea on how
to bridge that gap?  Is there anyone with experience sending a signal
from a unibus peripheral of some type to an RF modem over those distances?
   We would also be interested in hearing about experiences with Ethernets
over long distances (1000 feet or more).

   Please send replies to ...decvax!cornell!alison 
   or
   call Alison Brown
        Cornell COmputer Services
        (607) 256-4981