Re: ISDN access

Randy Frank (frank@engin.umich.edu)
Mon, 22 Aug 1994 15:38:38 -0400


I'm using Combinet bridges over ISDN, which do inverse multiplexing
over ISDN (so you get 128K bits/sec with both B channels open) (actually,
they don't technically do inverse multiplexing, they open two B channels
and then ping-pong packets over the two open channels).

Anyway, with both B channels open, the quality of what I get at home
is comparable to what I get at the office w/ a direct Ethernet
connection.

Hardware cost isn't cheap: office side is about $1,900, and home side
is about $600. Main difference between home and office unit is that
home (model CB-150) doesn't do packet filtering, as the assumption is
that there is only one ethernet device at home and that all traffic
generated at home is to be sent over the ISDN line. Office side
(model CB-400) is a true filtering bridge.

Randy Frank