WAN the internet and protocol

Lesson Objective:Understand the main terminology about networks.

Learning Outcome:Understand the different types of network and the advantage of each.

Wide Area Networks are usually spread out geographically.

The organisation usually owns and maintains the network equipment for a LAN, but the equipment used to make the WAN is owned and maintained by another organisation.

An example of a WAN. A company may have several international offices, they each have their own LAN.

Each computer on the LAN can communicate to others far away using a WAN

Connecting to the internet

ISP

The Internet

Modem or Router

The ISP services

…Plus others …eg.Video conf.Virtual Network

The two main uses of the internet.

Communicating with a modem or router

Digital data is stored as 0’s and 1’s

Digital information occurs in steps

Analogue information makes gradual changes

Analogue data can be stored as writing, sound, …etc.

What’s this?

MODEM

MOdulator

DEModulator

Answer questions about what equipment is used to transfer data and how it is done.

What does the Modem do?Data on the sending computer

Data on the receiving computer

The modem converts the digital data to analogue sound waves.

Sound waves transmitted.

The modem converts the analogue sound waves to digital data.

Examples of digital communications

Fax

Email

Video conferencing

What information is communicated?

IP Address:34.165.233.23

IP Address:52.43.234.192

IP Address:133.15.233.123

Each computer on the internet has a unique IP address. It is made up of four 8 bit bytes.

DNS (Domain name server)

DNS Server

What’s the ip address of www.bbc.co.uk?

 212.58.246.90

 212.58.246.90

Like using a phone bookto look up a number.

Protocol

Protocol is the way in which information is communicated

Protocol will break down this information into something useful

10011010101110100100010100100011010110101010101101001

10011010101110100100010100100011010110101010101101001

Send this informtion to 143 . 34. 145.183 Hello how are you …

Packets

Information on the internet (an on many LAN networks) is sent in packets

Packets are used so that no single computer can prevent other computers from ‘hogging’ the network.

Sending packets