
The Cambridge Ring was an experimental
local area network
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
architecture developed at the
Computer Laboratory, University of Cambridge
The Department of Computer Science and Technology, formerly the Computer Laboratory, is the computer science department of the University of Cambridge. it employed 35 academic staff, 25 support staff, 35 affiliated research staff, and about 15 ...
starting in 1974 and continuing into the 1980s. It was a
ring network
A ring network is a network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node – a ring. Data travels from node to node, with each node along the way handling ever ...
with a theoretical limit of 255
node
In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex).
Node may refer to:
In mathematics
* Vertex (graph theory), a vertex in a mathematical graph
* Vertex (geometry), a point where two or more curves, line ...
s (though such a large number would have badly affected performance), 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; thus in principle, there could be as many simultaneous senders as packets. The network ran over twin
twisted-pair
Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted bal ...
cabling (plus a
fibre-optic
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means ...
section).
There are strong similarities between the Cambridge Ring and an earlier ring network developed at
Bell Labs
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial research and scientific development company owned by mult ...
based on a design by
John R. Pierce. That network used
T1 lines at bit rate of 1.544 MHz and accommodating 522 bit messages (data plus address).
People associated with the project include
Andy Hopper
Sir Andrew Hopper (born 1953) is a British-Polish Computer Technologist and entrepreneur. He is treasurer and vice-president of the Royal Society, Professor of Computer Technology, former Head of the University of Cambridge Department of Compu ...
,
David Wheeler,
Maurice Wilkes
Sir Maurice Vincent Wilkes (26 June 1913 – 29 November 2010) was a British computer scientist who designed and helped build the Electronic Delay Storage Automatic Calculator (EDSAC), one of the earliest stored program computers, and who ...
, and
Roger Needham.
In 2002, the Computer Laboratory launched a graduate society called the
Cambridge Computer Lab Ring named after the Cambridge Ring.
See also
*
Cambridge Distributed Computing System
*
Internet in the United Kingdom § History
*
JANET
Janet may refer to:
Names
* Janet (given name)
* Janet (French singer) (1939–2011)
Surname
* Charles Janet (1849–1932), French engineer, inventor and biologist, known for the Left Step periodic table
* Jules Janet (1861–1945), French psych ...
*
NPL network
*
Packet switching
In telecommunications, packet switching is a method of grouping Data (computing), data into ''network packet, packets'' that are transmitted over a digital Telecommunications network, network. Packets are made of a header (computing), header and ...
*
Token Ring
Token Ring network
IBM hermaphroditic connector with locking clip. Screen contacts are prominently visible, gold-plated signal contacts less so.
Token Ring is a computer networking technology used to build local area networks. It was introduc ...
*
University of London Computer Centre
References
External links
Cambridge Ring HardwareCambridge Computer Lab Ring*
1974 introductions
Experimental computer networks
History of computing in the United Kingdom
Local area networks
Network topology
University of Cambridge Computer Laboratory
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