Networks Wide Area Networks/The Internet

Networks Wide Area Networks/The Internet

by Ben Dobson

​•The Internet is a collection of inter-connected networks

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​It allows email, video phone calling, file sharing as well as web browsing.

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​What is the difference between the internet and the world wide web?

Open Ended

What is the difference between the internet and the world wide web? (Use google)

​•​What is the difference between the internet and the world wide web?

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​The world wide web is a collection of web pages, web pages (HMTL) are transfered via Hyper Text Transfer Protocol. The Universal Resource Locator for web pages starts with www.

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​Email uses other protocols as does file transfer, video phone etc.

Open Ended

What are Wide Area Networks?(Use google)

​Wide area network

​a) Third party resources used e.g.telephone company

​b) Router needed to connect 2 networks

​(Or many routers to connect many networks)

Open Ended

1) Why do you need Internet protocol addresses?2) What are there 2 kinds? 3)Why did we create the new kind of IPAdresses?

​1) Why do you need Internet protocol addresses?

​To uniquely identify an device on a network

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2) What are there 2 kinds? IPv4. IPv6

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3)Why did we create the new kind of IPAdresses?

​Because there are so many devices we ran out of IPv4 addresses.

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​•https://www.youtube.com/watch?v=AYdF7b3nMto

Open Ended

Why wouldn’t circuit switching work for the connecting computers over the internet?

​Packets contain

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Packet Number  and

total number of packets.

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IP Address of Source and Destination

Error Checking to make sure packets are still intact (not corrupt)

Multiple Select

Packets contain

• Anti hacking code

• IP Address of source and destination machines

• Error checking data

• Total number of packets that make up a file

• The number of the packet

Open Ended

What do packets contain?

​

​Packets contain

​

Packet Number  and

total number of packets.

​

IP Address of Source and Destination

Error Checking to make sure packets are still intact (not corrupt)

Multiple Choice

What is a computer communication protocol?

• A computer language like python

• A file format like a word document

• A branch of mathematics

• A system of rules that allows computers to exchange information

A network protcol...​

​A system of rules that allows computers to exchange information

Multiple Choice

1)Why do we need to split up files into packets?

• Router using IP

• As one route may become slow, stop working so another so using another route would increase speed of transfer/reliability  

• Because communication line may fail in the middle of file transfer corrupting the file and wasting time

• TCP

Multiple Choice

1)Which protocol IP or TCP acts to check for errors?

• Router using IP

• As one route may become slow, stop working so another so using another route would increase speed of transfer/reliability  

• Because communication line may fail in the middle of file transfer corrupting the file and wasting time

• TCP

Multiple Choice

What hardware component determines where a packet will go next?

• Router using IP

• As one route may become slow, stop working so another so using another route would increase speed of transfer/reliability  

• Because communication line may fail in the middle of file transfer corrupting the file and wasting time

• TCP

Multiple Choice

Why might it be good that different packets in message might go by different routes?

• Router using IP

• As one route may become slow, stop working so another so using another route would increase speed of transfer/reliability  

• Because communication line may fail in the middle of file transfer corrupting the file and wasting time

• TCP

Multiple Choice

What is a Universal Resource Locator

• A human frendly web address

• Because IP/TCP protocols need to know IP Addresses not URL

• A list/database of URL and the associated IP addresses

• Request the IP address from a Domain name server higher up the DNS hierachy

Multiple Choice

What information does a Domain name server hold?

• A human frendly web address

• Because IP/TCP protocols need to know IP Addresses not URL

• A list/database of URL and the associated IP addresses

• Request the IP address from a Domain name server higher up the DNS hierachy

Multiple Choice

What does a Domain name server do if it can't resolve the IP Address for a URL?

• A human frendly web address

• Because IP/TCP protocols need to know IP Addresses not URL

• A list/database of URL and the associated IP addresses

• Request the IP address from a Domain name server higher up the DNS hierachy

Multiple Choice

Why do we need a Domain Name System?

• A human frendly web address

• Because IP/TCP protocols need to know IP Addresses not URL

• A list/database of URL and the associated IP addresses

• Request the IP address from a Domain name server higher up the DNS hierachy

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​•A Web Host is a company/person who possess a web server

•A web server is a computer that can provide html pages (web pages)

•Every web page you go to has to have a web server to provide that page.

WEB HOSTS/ SERVERS.

Fill in the Blank

•To connect a web server you must know it ........ name. (e.g. bbc.co.uk)

Fill in the Blank

•You must first connect to a domain name server that can give you the ........ (“resolve the ........”) for that url (domain name)

Fill in the Blank

•Then your computer can request the web page from the web .......

Fill in the Blank

•The web page (html file) is sent as many .......

Fill in the Blank

•The packets will be sent via many ...... (possibly not the same ones)

Requesting a web page involves...​

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•You must first connect to a domain name server that can give you the ip address (“resolve the ip address”) for that domain name (url).

•Then your computer can request the web page from the server.

•This is sent as many packets.

•The packets will be sent via many routers (possibly not the same ones)

Multiple Choice

•Why is useful that transmission of actual signals between devices is handled separately in a "lower layer protocol" than the protocols that handles sending packets across internet?

• To ensure packets arrive safely

• To count the number of packets

• To allow transmission to occur using differnent transmission media

• To allow a machine to have many Network interface cards