6.4.2+Communication+Features

=**__Principles of Networking__**=


 * All data transfer requires some connection between parties
 * People can access networks through a remote connection
 * This requires some connection though either the internet or a modem
 * People can also access networks locally with a direct connection
 * This means however that all connections are routed through the local network

__**Communication Channels**__
Telephone Lines
 * Traditional method
 * Allow communication through modems over the telephone system

Coaxial Cable
 * Allows modest transfer rates

Twisted Pair
 * Very common in LANs
 * Slightly more expensive than Coaxial Cable, but faster
 * Consists of at least two wires twisted around each other to cancel out electromagnetic interference for better connections

Fiber-optic
 * Uses single glass tubes to transmit data
 * Extremely fast, very secure
 * Very expensive
 * Lightweight

Microwave
 * Uses microwaves to send and receive data streams
 * Speeds of over 2Mbps

Satellite
 * Orbit earth
 * Used to relay radio signals

**__Communication Features of Networking__**
Ethernet
 * Used to control communication between servers and clients
 * Can operate with 10Mbps, 100Mbps and 1000Mbps
 * Mostly implemented through a star topology
 * Most common networking standard
 * Ethernet cabling is usually used to connect nodes to to the main network. At How [|Stuff Works]

ISDN
 * ISDN stands for //**I**ntegrated **S**ervices **D**igital **N**etwork//
 * It allows a minimum of at least 2 simultaneous connections
 * It is capable of most of people's complete communications needs (other than fast internet and television)

ADSL
 * ADSL stands for //**A**symmetric **D**igital **S**ubscriber **L**ine//
 * Is very fast and allows over 9Mbps transfer rate
 * Very cost effective

Fibre Optic
 * Uses very small glass tubes to transmit data using light
 * Fastest form of communication
 * Are used to provide a strong connection in LANs
 * Used mostly in industry because of their high cost

Wireless
 * Don't require cables
 * Use radio waves to transmit data
 * Have recently increased in speed very much

Public & private Telephone lines
 * Usually used by private home uses to connect to the internet (not common since the early 2000s)
 * Public lines allow communication via a public phone network
 * Private lines are secure and only allow certain users

__**Images**__

 * [[image:Coaxial_cable_cut.jpg width="300" height="220" caption="A Coaxial Cable (cut)"]] || [[image:ethernet_connector.jpg width="225" height="242" caption="A Ethernet connector"]] || [[image:Twisted_pair_cable.jpg width="250" height="229" caption="A Twisted Pair (cut)"]] || [[image:FIiber_optic.jpg width="435" height="194" caption="A Fiber Optic Cable"]] ||  ||

Created By: Daniel Gillo Last modified: 17th May 2012

Sources >
 * Isdn." 14 December 2010. Wikimedia.org. 16 December 2010. https://secure.wikimedia.org/wikipedia/en/wiki/Isdn
 * Jones, Richard. Computer Science Java Enabled. Victoria: IBID Press, 2004.