Networking

Understanding Computer Networks

O A computer network is a collection of computers, printers, and other devices that are interconnected by communication channels. Computer networks facilitate communications among users and allow users to share resources.

Advantages of Networks

OSharing Resources, OSecurity, OCommunication, OEducation, OProject Management .

Drawbacks of Networks

O Installation and maintenance cost

OViruses and trojan horsesONetwork can be useless in the

case of a crashing serverO Identity theftO Internet crimes

Network Types

OLAN (local area network)OMAN (metropolitan area

network)OWAN (wide area network)

LAN (Local Area Network)

Usually, if the devices on a network are in a single location, such as a building or a group of rooms, they are called a local area network (LAN). LANs usually have all the devices on the network connected by a single type of network cable or wireless connection.

MAN (Metropolitan Area Network)

A metropolitan area network (MAN) interconnects users with computer resources in a geographic area or region larger than that covered by a local area network (LAN) but smaller than the area covered by a wide area network (WAN).

MAN (Metropolitan Area Network)

WAN (Wide Area Network)

O If the devices are scattered widely, such as in different buildings or different cities, they are usually set up into several LANs that are joined together into a larger structure called a wide area network (WAN).

WAN (Wide Area Network)

Comparing LAN, MAN and WAN

Network Components

MediaO The term network media refers to the

pathways along which data travel. Network media is the actual path over which an electrical signal travels as it moves from one component to another. It provides connections between the network computers, peripherals, and devices in the network.

O There are four types of media technologies used in computer networks:

Coaxial cable

UTP (unshielded twisted pair)

Fiber Optic Cable

Wireless

Network Devices

OComputer networking devices are units that mediate data in a computer network. Computer networking devices are also called network equipment or communication devices.

NIC (network interface card)

Bridge

OA bridge device filters data traffic at a network boundary. Bridges reduce the amount of traffic on a LAN by dividing it into two segments.

Switch

OA network switch is a small hardware device that joins multiple computers together within one local area network (LAN).

Router

OWhen two or more networks must be connected, a router is usually necessary.