Requirements Of Network

Network Inteface Controller :-

       A network interface controller (also known as a network interface card, network adapter, LAN adapter and by similar terms) is a computer hardware component that connects a computer to a computer network

The NIC may use one or more of four techniques to transfer data:

Polling is where the CPU examines the status of the peripheral under program control.

Programmed I/O is where the microprocessor alerts the designated peripheral by applying its address to the system's address bus.[dubious – discuss]

Interrupt-driven I/O is where the peripheral alerts the microprocessor that it is ready to transfer data.

Direct memory access is where an intelligent peripheral assumes control of the system bus to access memory directly. This removes load from the CPU but requires a separate processor on the card.

Medium:-

Transmission Media:

A transmission medium (plural transmission media) is a material substance (solid, liquid, gas, or plasma) that can propagate energy waves. For example, the transmission medium for sound received by the ears is usually air, but solids and liquids may also act as transmission media for sound.

A transmission medium can be classified as a:

Linear medium, if different waves at any particular point in the medium can be superposed;

Bounded medium, if it is finite in extent, otherwise unbounded medium;

Uniform medium or homogeneous medium, if its physical properties are unchanged at different points;

Isotropic medium, if its physical properties are the same in different directions.

Medium are mainly divided in to 2 types

                                      1.Guided Medium

                                      2.Un-Guided Medium

Guided Medium:-

       These are mainly divided into  1.Fiber

                                                    2.Co-axial

                                                    3.Twisted

                                                           1.UTP

                                                           2.STP

UN-Guided Medium:-

       These are mainly divided into   1.Infrared

                                                     2.RF(Radio Frequency)

Types of Network Equipment:-

Hubs provide a central location for attaching wires to workstations. There are two types: passive and active.

Switches connect devices to host computers and allow large numbers of these devices to share a limited number of ports.

Routers are protocol-dependent devices that connect sub-networks or divide a very large network into smaller sub-networks.

Repeaters use regeneration and retiming to ensure that signals are transmitted clearly through all network segments.

Bridges are used to interconnect local or remote networks. They centralize network administration.

Gateways can interconnect networks with different, incompatible communications protocols.

Multiplexers combine multiple signal inputs into one output.

Transceivers connect nodes and send and receive signals.

They are sometimes called medium access units (MAU).

Firewalls safeguard a network against unauthorized access.

Other network devices such as wireless access points (WAP) and modular platforms are also available.