A NETWORK SWITCH

NETWORK SWITCH
A network switch
Basically ,while constructing computer network ,we need share information between many computers ,switch is one of those devices that here we will discuss
A network switch is a computer networking device that links network segments or network devices. The term commonly refers to a multi-port network bridge that processes and routes data at the data link layer (layer 2) of the OSI model.

A network switch is a telecommunication device which receives a message from any device connected to it and then transmits the message only to the device for which the message was meant. This makes the switch a more intelligent device than a hub (which receives a message and then transmits it to all the other devices on its network). The network switch plays an integral part in most modernEthernet local area networks (LANs). Mid-to-large sized LANs contain a number of linked managed switches. Small office/home office(SOHO) applications typically use a single switch, or an all-purpose converged device such as a residential gateway to access small office/home broadband services such as DSL or cable Internet. In most of these cases, the end-user device contains a router and components that interface to the particular physical broadband technology. User devices may also include a telephone interface forVoIP.

An Ethernet switch operates at the data link layer of the OSI model to create a separate collision domain for each switch port. With 4 computers (e.g., A, B, C, and D) on 4 switch ports, any pair (e.g. A and B) can transfer data back and forth while the other pair (e.g. C and D) also do so simultaneously, and the two conversations will not interfere with one another. In full duplex mode, these pairs can also overlap (e.g. A transmits to B, simultaneously B to C, and so on). In the case of a repeater hub, they would all share the bandwidth and run in half duplex, resulting in collisions, which would then necessitate retransmissions.