[mod.protocols.tcp-ip] Ethernet Multiplexors

mckenzie@j.bbn.com (Alex McKenzie) (09/15/86)

We have had various troubles attaching hosts to our BBN Ethernet using DELNIs.
We haven't actually tried too hard to diagnose them all - simply noted that
there are hosts which don't work when connected to a DELNI.  We assume that DEC
has probably "improved" or ignored some part of the host to transceiver
protocol.  We are now using large quantities of an Ethernet multiplexor made by
TCL, Inc., 41829 Albrae St., Fremont, CA 94538 (415/657-3800).  You buy a
chassis with 9 card slots.  You buy a "downstream" card and 1 to 8 "upstream"
cards.  Each upstream card can be either V1 or 802.3; I think this is also true
of the downstream card but I'm not so sure.  As I recall, a box with a
downstream card costs about $400 and each upstream card costs about $100.  We
have had no troubles with these multiplexors, have successfully cascaded them,
and I know of no hosts that can't use them.

Regards,
Alex McKenzie