Computer networking

9 Computer networking

Terminology

Asynchronous Transfer Mode (ATM)	A fast and expensive method of setting up a computer network; tends to be used to provide the backbone to a system
Backbone	A physical connection between hubs that carries all data back to the server
Bandwidth	The amount of information in bits per second (bps), kilobits per second (kbps), or megabits per second (Mbps) that can be sent via a communication channel or a network connection in a set period of time, i.e. the speed of the system
Bus	• A set of wires between computers where two signals can travel side by side • The signals can start and finish at any point in the system • The bus has no control of what is sent and when it is sent
Collision	When two or more computers try to send data at the same time down the same network
Deterministic	The method of calculating how long it will take data to travel round a network and how quickly the system can be accessed
Ethernet	A method of setting up a computer network developed by Xerox, using cabling to connect the parts of the system together
Global Area Network (GAN)	Worldwide connecting systems, e.g.

• Internet

• Telecommunications

Hub

• Equipment that receives information from a network interface card

• Re-times the information

• Sends the information to its destination

IP Address

• Each node on a system is given its own unique number

• Formed by four larger numbers separated by dots, e.g.

12.345.678.9

• Allows data to be sent to the correct destination

ISDN ConnectionA digital telephone line allowing computer connectionsLocal Area Network (LAN)A method of linking computers, printers, etc. within a building to enable the sharing of data between computersMetropolitan Area Network (MAN)Linking of local area networks over a local districtModemDevice connecting computers to the telephone system Consists of:

• Modulator – converts computer signal to an audio signal

• Demodulator – converts incoming audio signal to a digital signal

NetworkA method of linking computers, printers, etc. to enable the sharing of data between themNetwork Interface Cards (NICs)

• Cards that control the flow of data between a computer and the hub

• Have collision detection circuits

• Therefore if two sets of data are sent at identical times from two different machines