Flow of Data across the internet

TCP =Transmission Control Protocol IP = Internet ProtocolTCP/IP ProtocolProtocolsSystems communicate using a protocol, or a language.Protocols are sometimes called a handshakeTCP/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 ProtocolSMTP Simple Mail Transfer Protocol (for sending mail)POP Post Office Protocol (for downloading mail)IMAP Internet Access Message ProtocolFTP File Transfer Protocol (transferring files between computers)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 networkingIP protocol routes the IP datagramsIP software moves the packets across the networkSmaller 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

Open Systems Interconnection (OSI) Model Your computer 'talks' to other computers connected to the Internet via the TCP/IP protocol stack built into the computer's operating systemDatagrams 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. At the destination, the packets now go upwards through the stack. 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 LAYERLink or Hardware layer: converts binary data between network signalsTransport/TCP Layer directs packets via port no. to specific applicationInternet Layer IP directs packets to specific computer using IP addressTCP/IP Protocol StackSummaryTCP breaks data into smaller packets or IP datagrams

IP ensure the IP datagrams are routed and reach their destination

Links to short video clipsNetworking: what is TCP/IP? http://www.youtube.com/watch?v=NePWnrqUMZ8How TCP/IP Works?http://www.youtube.com/watch?v=JBqD3D7LE3chttp://www.youtube.com/watch?v=XGZ0Cao_o_E&feature=related (ip4 ipv6)How the TCP/IP Protocol works (link - http://www.youtube.com/watch?v=HOaIqQAeaik&feature=related)How the internet works- http://www.youtube.com/watch?v=7_LPdttKXPc&feature=relatedStep by Step in more detail

Say you wanted to send a message to another computerThe message would start at the top of the protocol stack on your computer and work it's way downwardOn the Internet, these chunks of data are known as packets.After going through the TCP layer, the packets proceed to the IP layer. This is where each packet receives it's destination address - IP addressThe ISP has a direct connection to the Internet. The ISPs router examines the destination address in each packet and determines where to send it. 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. When the data reaches the top of the stack, the packets have been re-assembled into their original form