Cambridge Ring (computer network)

The Cambridge Ring was an experimental <a href="/facts/Local_area_network/edUDxJ6J">local area network</a> architecture developed at the <a href="/facts/Computer_Laboratory,_University_of_Cambridge/Dd9unFtw">Computer Laboratory, University of Cambridge</a> starting in 1974 and continuing into the 1980s. It was a <a href="/facts/Ring_network/GDnXYWDv">ring network</a> with a theoretical limit of 255 <a href="/facts/Node_(networking)/LBp2vNcJ">nodes</a> (though such a large number would have badly affected performance), around which cycled a fixed number of <a href="/facts/Network_packet/xCYf8SJu">packets</a>. Free packets would be "loaded" with data by a sending machine, marked as received by the destination machine, and "unloaded" on return to the sender; thus in principle, there could be as many simultaneous senders as packets.
The network ran over twin <a href="/facts/Twisted-pair/L426Jk2C">twisted-pair</a> cabling (plus a <a href="/facts/Fibre-optic/5ruuIFbj">fibre-optic</a> section) at a raw data rate of 10 megabits/sec.
There are strong similarities between the Cambridge Ring and an earlier ring network developed at <a href="/facts/Bell_Labs/fKP5Gk0H">Bell Labs</a> based on a design by <a href="/facts/John_R._Pierce/mq8bfrLb">John R. Pierce</a>. That network used <a href="/facts/T1_line/cghJPRpQ">T1 lines</a> at bit rate of 1.544 MHz and accommodating 522 bit messages (data plus address).
People associated with the project include <a href="/facts/Andy_Hopper/DEdkYdKI">Andy Hopper</a>, <a href="/facts/David_Wheeler_(computer_scientist)/eMm8hmrz">David Wheeler</a>, <a href="/facts/Maurice_Wilkes/2RJ58EKc">Maurice Wilkes</a>, and <a href="/facts/Roger_Needham/sSz9TUYM">Roger Needham</a>.
A 1980 study by <a href="/facts/Peter_Cowley/TcvBADq8">Peter Cowley</a> reported several commercial implementors of elements of the network, ranging from <a href="/facts/Ferranti/UA1e5VBN">Ferranti</a> (producing <a href="/facts/Gate_array/NsnPf9c0">gate arrays</a>), <a href="/facts/Inmos/wD1JHHf8">Inmos</a> (a <a href="/facts/Semiconductor/zFf3mGTE">semiconductor</a> manufacturer), <a href="/facts/Mergenthaler_Linotype_Company/V7STUJyY">Linotype Paul</a>, <a href="/facts/Logica/8JnpJLtt">Logica</a> VTS, MDB Systems, and Toltec Data (a design company who manufactured interface boards).
In 2002, the Computer Laboratory launched a graduate society called the <a href="/facts/Cambridge_Computer_Lab_Ring/uHIBhkwo">Cambridge Computer Lab Ring</a> named after the Cambridge Ring.

Cambridge Ring (computer network) open-in-new

Cambridge Ring (computer network)