The Cambidge Ring
was an experimental local area network
architecture developed at the Cambridge University
Computer Laboratory in the mid-late 1970s
and early 1980s
. It used a ring topology with a theoretical limit of 255 nodes (though such a large number would have badly affected perfomance), around which cycled a fixed number of packets. Free packets would be "loaded" with data by a machine wishing to send, marked as received by the destination machine, and "unloaded" on return to the sender. The network ran over twin twisted-pair cabling (plus a fibre-optic section).
See also: token ring.