Ethernet
<networking> A local area network first described by Metcalfe & Boggs of
Xerox PARC in 1976. Specified by DEC, Intel and XEROX (DIX) as IEEE 802.3 and
now recognised as the industry standard.
Data is broken into packets and each one is transmitted using the CSMA/CD
algorithm until it arrives at the destination without colliding with any other
packet. The first contention slot after a transmission is reserved for an
acknowledge packet. A node is either transmitting or receiving at any instant.
The bandwidth is about 10 Mbit/s. Disk-Ethernet-Disk transfer rate with TCP/IP
is typically 30 kilobyte per second.
Version 2 specifies that collision detect of the transceiver must be activated
during the inter-packet gap and that when transmission finishes, the
differential transmit lines are driven to 0V (half step). It also specifies some
network management functions such as reporting collisions, retries and
deferrals.
Ethernet cables are classified as "XbaseY", e.g. 10base5, where X is the data
rate in Mbps, "base" means "baseband" (as opposed to radio frequency) and Y is
the category of cabling. The original cable was 10base5 ("full spec"), others
are 10base2 ("thinnet") and 10baseT ("twisted pair") which is now (1998) very
common. 100baseT ("Fast Ethernet") is also increasingly common.
Usenet newsgroup: comp.dcom.lans.ethernet.
http://wwwhost.ots.utexas.edu/ethernet/ethernet-home.html.
(1997-04-16)
Nearby terms:
e-text « ETHER « EtherGate « Ethernet »
Ethernet address » Ethernet meltdown » EtherTalk
|
