1. TCP =Transmission Control Protocol IP = Internet Protocol TCP/IP Protocol

2. Protocols Systems communicate using a protocol, or a language. Protocols are sometimes called a “handshake” TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language or protocol of the Internet. The following protocols require TCP/IP to function: HTTP – Hypertext Transfer Protocol SMTP – Simple Mail Transfer Protocol (for sending mail) POP – Post Office Protocol (for downloading mail) IMAP – Internet Access Message Protocol FTP – File Transfer Protocol (transferring files between computers)

3. TCP enables data to be split into smaller IP datagrams - small packets of data which can be re- assembled at the receiving end. TCP ensures the IP datagrams are re-assembled in the right order and ensures the process is completed TCP protocol fragments data into smaller IP datagrams (packets) IP Datagrams TCP enables networking

4. IP protocol routes the IP datagrams IP software moves the packets across the network Smaller packets (IP Datagrams) move between nodes (routers, servers and dedicated machines) The datagrams/packets are re-assembled at the receiving end by the TCP software the correct order and any mistakes are corrected

5. Open Systems Interconnection (OSI) Model 1. Your computer 'talks' to other computers connected to the Internet via the TCP/IP protocol stack built into the computer's operating system 2. Datagrams move down through the TCP layer to the IP layer where it receives it's destination IP address. The ISP (Internet Service Provider) router examines the destination address to know where to send it. 3. At the destination, the packets now go upwards through the stack. 4. When the data reaches the top of the stack, the packets have been re- assembled into their original form HIGHEST LAYER Applications protocols layer (http, smtp, pop, ftp, https, etc) LOWEST LAYER Link or Hardware layer: converts binary data between network signals Transport/ TCP Layer – directs packets via port no. to specific application Internet Layer IP directs packets to specific computer using IP address TCP/IP Protocol Stack

6. Summary TCP breaks data into smaller packets or IP datagrams IP ensure the IP datagrams are routed and reach their destination

7. Links to short video clips Networking: what is TCP/IP? http://www.youtube.com/watch?v=NePWnrqUMZ8 http://www.youtube.com/watch?v=NePWnrqUMZ8 How TCP/IP Works? http://www.youtube.com/watch?v=JBqD3D7LE3c http://www.youtube.com/watch?v=JBqD3D7LE3c 1. http://www.youtube.com/watch?v=XGZ0Cao_o_E& feature=related (ip4 ipv6) http://www.youtube.com/watch?v=XGZ0Cao_o_E& feature=related 2. How the TCP/IP Protocol works (link - http://www.youtube.com/watch?v=HOaIqQAeaik&f eature=related) http://www.youtube.com/watch?v=HOaIqQAeaik&f eature=related 3. How the internet works- http://www.youtube.com/watch?v=7_LPdttKXPc&f eature=related http://www.youtube.com/watch?v=7_LPdttKXPc&f eature=related

8. Step by Step in more detail 1.Say you wanted to send a message to another computer 2.The message would start at the top of the protocol stack on your computer and work it's way downward 3.On the Internet, these chunks of data are known as packets. 4.After going through the TCP layer, the packets proceed to the IP layer. This is where each packet receives it's destination address - IP address 5.The ISP has a direct connection to the Internet. The ISPs router examines the destination address in each packet and determines where to send it. 6.As the packets go upwards through the stack, all routing data that the sending computer's stack added (such as IP address and port number) is stripped from the packets. 7.When the data reaches the top of the stack, the packets have been re-assembled into their original form