Networking Objectives Understand the key terms and ideas of a computer network LAN vs WAN IP address What is a packet? Networked vs stand alone Advantages of networking

Networking What is a network? A computer network is where many computers are connected together. Networked computers can share files, offer services (such as email) and allow communication. The biggest network in the world is the internet!

5) Virtual network computing (VNC) Networking Activity You will be given one of the following networked services. You must prepare a short description of it. 1) Google+ 2) Twitter 3) Iplayer 4) Dropbox 5) Virtual network computing (VNC)

Networking Networks come in many sizes Networks differ in sizes. At home you will most likely have a small network set up already. This is referred to as a Local Area Network or a LAN. How do you know you have a network at home? If you have broadband and have wireless then you will have a network! School has a bigger network with many more computers connected together. This too is referred to as a LAN. Local refers to the computers being near each other geographically rather than the number of computers connected to the network. The internet is a network of computers which are connected all over the world. This means you can access websites from many different countries. This network is spread over a large geographical area and so is referred to as a wide area network or a WAN.

Networking IP address In order for computers to talk to one another each one must have a unique address. This is known as an IP address (internet protocol address). A IP address is made up of 4 sets of numbers ranging from 0 to 254. E.g. 192.168.0.1 You can think of a IP address like a postal address. In order for a letter to arrive at the correct house you must write the correct address on the envelope. For a computer message to get to it’s destination it must have an IP address.

Choose one person in your group to report back with your idea. Networking Activity We are running out of IP addresses! Arrgghh! There are only about 4% of IP addresses left to allocate. This means we need a new solution. In groups try and decide on a way of giving a unique address to computers so that we would never run out of addresses and each address would always be guaranteed to be unique. Choose one person in your group to report back with your idea. Note – Your not allowed to use the internet for this task AND IPv6!

Networking Packets When data is sent on a computer network it is sent in binary. Music, images and text are all converted into binary in the same way you have already leaned about in your binary section. Files, emails and music which are to be sent on a network are split into chunks of equal size. These are called packets. Packets then have extra information added so they can get to the destination correctly (like IP address). This is known as a header. Destination IP 192.168.0.25 Source IP 192.168.0.21 Data! Header

Networking How does it work? Large music file A large file needs to be sent from computer A to B. Each one has it’s own IP address. A B IP – 192.168.5.64 IP – 192.168.5.28

Networking How does it work? Large music file Chunk 1 Chunk 2 Chunk 3 Chunk 4 Chunk 5 Chunk 6 The file needs to be split up into small chunks. Chunk 6 will not be full of data. A B IP – 192.168.5.64 IP – 192.168.5.28

Networking How does it work? The first chunk is prepared by adding the source and destination IP address on. Source 192.168.5.28 Destination 192.168.5.64 Chunk 1 B A IP – 192.168.5.64 IP – 192.168.5.28

Networking How does it work? The packet is then sent from computer A to computer B B A Chunk 1 D S IP – 192.168.5.64 IP – 192.168.5.28

Networking How does it work? The second chunk is then sent and so on until the whole file has been sent. B A Chunk 2 D S IP – 192.168.5.64 IP – 192.168.5.28

Networking Activity Make notes on the following. You may wish to create a new powerpoint for networking. WAN and LAN IP address Network packet

Networking Activity Make notes on the following. You may wish to create a new powerpoint for networking. WAN and LAN IP address Network packet

Networking Stand alone A stand alone computer is one which is not connected to a network. This includes not being connected to the internet. A stand alone computer does have some advantages over a networked one – Less chance of viruses as most viruses come from the network. Computer will still work even if the network is down or faulty No slow down caused by a busy network Can not be remotely hacked. Only susceptible to attack if someone is physically in front of the computer. However a stand alone computer will not be able to use networked services which is the biggest disadvantage. For example if PC’s at school were stand alone you would always have to use the same computer to access your files.

Networking Advantages of networking A networked computer has a number of advantages – Able to share peripherals such as printers. Access files on any computer by downloading them from a file server. Share internet connection so every PC can access the internet. Be able to use communication services, like email or skype, which offer much more flexibility and functionality over post and telephone calls. Work collaboratively on files and projects Have shared file areas so everyone has access to certain files. The network system at school offers these advantages. Each room has a shared printer so you do not have to log onto a special “printing” computer. You can access your N drive (your files) from any PC and also access resources from the students drive (O drive). You can email and all have access to the internet from any PC. Even though the network is slow sometimes the advantages do outweigh the disadvantages.

Networking Activity What would happen if we did not use networking at school. What problems would we face? Write a short essay on what problems we would face without the network. Also consider would there be any advantages and how could we work around not having a network.

Make notes on the following Advantages of networking. Networking Activity Make notes on the following Advantages of networking. Include your essay as part of your notes.