Online Computer Terms Dictionary - E

ETHER

<language> A concurrent object-oriented language?

(1997-03-18)

EtherGate

Multi-protocol Ethernet gateway made by LRT. See Computer Systems, October 1985.

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)

Ethernet address

<networking> (Or "MAC address") The physical address identifying an individual Ethernet controller board. An Ethernet addess is a 48-bit number aabbccddeeff where a-f are hexadecimal digits. The first 24 bits, aabbcc, identify the manufacturer of the controller. The Ethernet address is hard-wired on some controllers, stored in a ROM on some, and others allow it to be changed from software. It is usually written as six hexadecimal numbers, e.g. 08:00:20:03:72:DC.

See also ARP, Internet address.

(1996-02-21)

Ethernet meltdown

A network meltdown on Ethernet.

(1994-11-29)

EtherTalk

<networking> An Apple Computer network standard used to extend an AppleTalk network across an Ethernet network.

Compare LocalTalk.

(1994-11-29)

ethics

computer ethics