1. Rhys McBreen (How the internet works) X

2. Contents The Layers and what they do IP Addressing X

3. Layers Application Layer Host-to-Host Layer Internet Layer Network Interface Layer These layers stack on top of each other to form the basic TCP/IP structure and functionality X

4. Application Layer This has to accommodate for all of the things an application might want to do, so it has the most protocols of any layer, these are a few: Hypertext Transfer Protocol(HTTP) File Transfer Protocol(FTP) Simple Mail Transfer Protocol(SMTP) Domain Name System(DNS) Routing Information Protocol(RIP) X

5. Hypertext Transfer Protocol This is used for viewing pages on the internet X

6. File Transfer Protocol Is for simple file transfer, like downloading a file. X

7. Simple Mail Transfer Protocol Is for things like hotmail, etc. This is the protocol for mail transfer from a mail server to a client computer X

8. Domain Name System Ever wondered how your computer knows what server to connect to when you type in ‘facebook.com’? This is the protocol that gets the IP address of the server from one of the many DNS servers across the world. This finds the nearest DNS server, connects to it, and requests the IP of the website your trying to access. For example, facebook.com turns into 69.63.189.11 This is used because facebook.com is far easier to remember than 69.63.189.11 X

9. Routing Information Protocol This gives a computers network card information as to where to route the packets through Instead of the computer sending the packet to every other computer on the internet, this gives a simple, easy path for the data to go through X

10. Host-to-Host (Transport) Layer This is what the application layer calls on if it needs data, or needs to send data This has two protocols: Transmission Control Protocol User Datagram Protocol X

11. Transmission Control Protocol This give a one to one connection service that is reliable This also manages errors such as packet loss, sequencing and acknowledgment of how many packets were sent X

12. User Datagram Protocol UDP is a one to one or one to many communication service It’s very unreliable and connectionless UDP is used when: the data wanting to be sent is very small (one packet) you don’t want to have the bother of setting up a TCP connection when the applications provide reliable delivery X

13. Internet layer This handles addressing, packaging and routing functions This has many protocols such as: Internet Protocol(IP) Address Resolution Protocol(ARP) Internet Control Message Protocol(ICMP) Internet Group Management Protocol(IGMP) X

14. Internet Protocol This is an unreliable, connectionless protocol for routing between hosts This protocol makes its best effort to get the data to the receiving host If a piece of data does not get through, this protocol does not attempt to recover that piece of data. X

15. Address Resolution protocol This resolves the MAC address (a unique number given to every network capable device) It helps to deliver the packets to the receiving host by giving the packets a path to go through X

16. Internet Control Message Protocol This is the protocol that makes sure that all of the packets go through the network If a packet is not delivered, or is lost during transmission, this protocol sends another request to send the packet X

17. Internet Group Management Protocol This manages groups of hosts (computers, routers, etc) The groups can be of any size X

18. Network Interface Layer This handles placing ‘packets’ of data on and off of the network medium This is designed to give the layers that stack on top of this to be able to function normally across any network medium X

19. IP Addressing IP addresses consist of 4, 8 bit “octets” that when grouped together, make up the IP address of any network capable device. There are 3 classes of IP address: Class A Class B Class C X

20. Class A IP Addresses These IP addresses make up the base on which all network capable devices stand These types of IP addresses allow 126 networks and 16,777,214 devices. These are used for major networks or ISPs X

21. Class B IP Addresses These classes of IP addresses are for large networks, such as universities, schools and large businesses They allow for 16,384 networks, under each class A IP address, and 65,534 hosts, or users, in each network X

22. Class C IP Addresses These are for smaller networks, such as home networks, small businesses, and other places such as libraries These IP addresses allow for over 2,097,152 networks, but each with only 254 devices X

23. Bibliography http://technet.microsoft.com/en-us/library/cc786128(WS.10).aspx X

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