Network segment
Encyclopedia
A network segment is a portion of a computer network
. The nature and extent of a segment depends on the nature of the network and the device or devices used to interconnect end stations.
In the original 10BASE5
and 10BASE2
Ethernet varieties, a segment would therefore correspond to a single coax cable and any devices tapped into it. At this point in the evolution of Ethernet, multiple network segments could be connected with repeaters (in accordance with the 5-4-3 rule
) to form a larger collision domain
.
By the IEEE definition, on modern twisted-pair Ethernet, a network segment would correspond to the individual connection between end station to network equipment (i.e. repeater
, hub
or switch
) or the connections between different pieces of network equipment.
Although the above definition would indicate that, through the use of repeaters or hubs, it is possible to have multiple network segments within a collision domain, the term is sometimes used as a synonym for collision domain
.
for token ring are part of the same network segment.
are part of the same network segment.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
. The nature and extent of a segment depends on the nature of the network and the device or devices used to interconnect end stations.
Ethernet
According to the defining IEEE standards for Ethernet, a network segment is an electrical connection between networked devices.In the original 10BASE5
10BASE5
10BASE5 was the original commercially available variant of Ethernet.For its physical layer it used cable similar to RG-8/U coaxial cable but with extra braided shielding. This is a stiff, diameter cable with an impedance of 50 ohms , a solid center conductor, a foam insulating filler, a shielding...
and 10BASE2
10BASE2
10BASE2 is a variant of Ethernet that uses thin coaxial cable , terminated with BNC connectors...
Ethernet varieties, a segment would therefore correspond to a single coax cable and any devices tapped into it. At this point in the evolution of Ethernet, multiple network segments could be connected with repeaters (in accordance with the 5-4-3 rule
5-4-3 rule
The 5-4-3 rule also referred to as the IEEE way is a design guideline for Ethernet computer networks covering the number of repeaters and segments on shared-access Ethernet backbones in a tree topology. It means that in a collision domain there should be at most 5 segments tied together with 4...
) to form a larger collision domain
Collision domain
A collision domain is a section of a network where data packets can collide with one another when being sent on a shared medium or through repeaters, in particular, when using early versions of Ethernet. A network collision occurs when more than one device attempts to send a packet on a network...
.
By the IEEE definition, on modern twisted-pair Ethernet, a network segment would correspond to the individual connection between end station to network equipment (i.e. repeater
Repeater
A repeater is an electronic device that receives asignal and retransmits it at a higher level and/or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.-Description:...
, hub
Ethernet hub
An Ethernet hub, active hub, network hub, repeater hub or hub is a device for connecting multiple Ethernet devices together and making them act as a single network segment. A hub works at the physical layer of the OSI model. The device is a form of multiport repeater...
or switch
Network switch
A network switch or switching hub is a computer networking device that connects network segments.The term commonly refers to a multi-port network bridge that processes and routes data at the data link layer of the OSI model...
) or the connections between different pieces of network equipment.
Although the above definition would indicate that, through the use of repeaters or hubs, it is possible to have multiple network segments within a collision domain, the term is sometimes used as a synonym for collision domain
Collision domain
A collision domain is a section of a network where data packets can collide with one another when being sent on a shared medium or through repeaters, in particular, when using early versions of Ethernet. A network collision occurs when more than one device attempts to send a packet on a network...
.
Token ring
All end stations connected to the same Media Access UnitMedia Access Unit
A Media Access Unit is a device to attach multiple network stations in a star topology in a token ring network, internally wired to connect the stations into a logical ring. The MAU contains relays to short out nonoperating stations...
for token ring are part of the same network segment.
Token bus
All end stations connected to the same token busToken bus
Token bus is a network implementing the token ring protocol over a "virtual ring" on a coaxial cable. A token is passed around the network nodes and only the node possessing the token may transmit. If a node doesn't have anything to send, the token is passed on to the next node on the virtual ring...
are part of the same network segment.
Other uses
- The term network segment is sometimes used to refer to the portion of a computer networkComputer networkA computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
in which computers can access each other using a data link layerData link layerThe data link layer is layer 2 of the seven-layer OSI model of computer networking. It corresponds to, or is part of the link layer of the TCP/IP reference model....
protocol (e.g., in Ethernet, this would be the ability to send an Ethernet packet to others using their MAC addresses). In this case, it is synonymous with broadcast domainBroadcast domainA broadcast domain is a logical division of a computer network, in which all nodes can reach each other by broadcast at the data link layer. A broadcast domain can be within the same LAN segment or it can be bridged to other LAN segments....
. - Occasionally, the term refers to a subnetworkSubnetworkA subnetwork, or subnet, is a logically visible subdivision of an IP network. The practice of dividing a network into subnetworks is called subnetting....
. - It is also applied to a language space within the Internet, such as RunetRunetCurrently Internet access in Russia is available to businesses and home users in various forms, including dial-up, cable, DSL, FTTH, mobile, wireless and satellite...
or KaznetKaznetThe Internet in Kazakhstan is growing rapidly. Between 2001 and 2005, the number of Internet users increased from 200,000 to 1 million. By 2007, Kazakhstan reported Internet penetration levels of 8.5 percent, rising to 12.4 percent in 2008...
.