Charles Hedrick (email@example.com)
Wed, 16 Sep 87 23:59:47 EDT
We have three situations similar to what you describe, i.e. pairs of
IP networks connected by T1. We are using the following three
- VAXes running Ultrix with the T1 line connected to DMR11's.
Avanti T1 Mux's are used to cut down the speed, since
no known DEC line controller can deal with speeds this
high. This is probably the cheapest of the 3 methods,
if you already have the VAXes, but also give the worst
performance and has other disadvantages.
- Cisco IP routers, using either Digilink T1-izers (boxes that
take a vanilla 1.5Mb synchronous signal and format it
for T1) or Avanti T1 muxes (for cases where we need
to use the line for things other than the IP link, e.g.
talking to 3270 cluster controllers at the other site).
This is my preferred solution. (Of course vendors other
than Cisco also make routers that would do this. You
might want to talk to Proteon and U-B also.)
- U-B bridges. These would also need either a T1-izer or
T1 mux. These are level 2 bridges rather than level 3
routers, which have both advantages and disadvantages.
(They have been discussed so often that I am not about
to repeat the discussion.) The U-B bridges have worked
very well, but note that you must dedicate an IBM PC
or clone to boot them. (I believe the same PC can be
shared for booting all U-B products.) I strongly oppose
the use of this approach if the two IP networks are
under different administration, and if you don't have
support staff available at both ends. Junk coming from
the other end can sink your network.
This archive was generated by hypermail 2.0b3 on Thu Mar 09 2000 - 14:39:15 GMT