10BASE2
10BASE2 (also known as cheapernet or thinnet) is a variant of Ethernet that uses thin coaxial cable (RG-58 or similar, as opposed to 10BASE5 cable), terminated with BNC connectors. Each segment of cable is connected to the workstation using a T-piece, with one segment coming in on each arm of the T. At the physical end of the network, the T-piece attached to the workstation would require a 50-ohm terminator.
When wiring a 10base2 network, special care has to be taken that cables should be properly connected to all T-pieces, and appropriate terminators should be plugged in. Bad contacts or shorts are especially difficult to diagnose, though special (and costly) measurement devices are available. Any failure on any point of the line tends to prevent any communication. For this reason, 10base2 networks were a bit uneasy to maintain and were often replaced by 10baseT networks, which had a good upgrade path to 100baseTX.
The name 10BASE2 is derived from several characteristics of the physical medium. The 10 comes from the maximum transmission speed of 10 Mb/s (millions of bits per second). The BASE stands for baseband signalling, and the 2 represents a rounded up shorthand for the maximum segment length of 185 metres.
See also
References
This article was originally based on material from the Free On-line Dictionary of Computing, which is used under the GFDL.
fr:10BASE2