Computer Networking

Computer Network

A collection of computers and other hardware devices that are connected together to share hardware, software, and data as well as to communicate with one another


LAN (Local Area Network) : covers relatively small geographical area : home,
WAN (Wide Area Network) Covers large geographical area. It consists of two or more LAN and connected together using communications technology Internet is the largest WAN
MAN (Metropolitan Area Networks) school, office Network design to service a metropolitan area i.e a city . Consist of multiple LAN Size between LAN and WAN
PAN (Personal Area Networks) Network of personal devices:
printer, mobile devices, etc.. Wired or wireless

computer network can be categorized according to three properties:

1. typology
2. protocol
3. architecture  

Network topology is the layout pattern of interconnections of the various elements (links, notes) of a computer network. It is the geometrical arrangement of the network. The picture below show the different arrangement of the network.

 A network protocol defines rules and conventions for communication between network devices. 

The most common network protocols are:

1. Ethernet
2. Local Talk
3. Token Ring
4. FDDI
5. ATM

A network architecture is the specification of design principles (including data formats and procedures) for creating a network configuration of data processors. Two most common network are peer- to- peer and server/client network There are two types of transmission media; bounded and unbounded. 

     • Bounded Media         • Unbounded Media (air or a vacuum)

- Twisted pair wire        - AM and FM radio

- Co-axial cable             - TV broadcasting

- Fiber optic cables        - Satellite communication

- Microwave radio

- Infrared signals 

- Below are some examples of network electronic device and

their properties:

• A network bridge connects multiple network segments.A bridge uses a forwarding database to send frames across network segments.

• A router is a device that forwards data packets between computer networks, creating an overlay internetwork. A router is connected to two or more data lines from different networks.

•  hub is a device for connecting multiple Ethernet devices together and making them act as a single network segment.

• gateway is used to interfaced with other network.A gateway is a network point that acts as an entrance to another network
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