TCP and IP were developed by a Department of Defense (DOD) research project to connect a number different networks designed by different vendors into a network of networks (the "Internet"). It was initially successful because it delivered a few basic services that everyone needs (file transfer, electronic mail, remote logon) across a very large number of client and server systems. Several computers in a small department can use TCP/IP (along with other protocols) on a single LAN. The IP component provides routing from the department to the enterprise network, then to regional networks, and finally to the global Internet. On the battlefield a communications network will sustain damage, so the DOD designed TCP/IP to be robust and automatically recover from any node or phone line failure. This design allows the construction of very large networks with less central management. However, because of the automatic recovery, network problems can go undiagnosed and uncorrected for long periods of time. As with all other communications protocol, TCP/IP is composed of layers:

Is responsible for moving packet of data from node to node. IP forwards each packet based on a four byte destination address (the IP number xxx.xxx.xxx.xxx). The Internet authorities assign ranges of numbers to different organizations. The organizations assign groups of their numbers to departments. IP operates on gateway machines that move data from department to organization to region and then around the world.

Is responsible for verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received. Sockets - is a name given to the package of subroutines that provide access to TCP/IP on most systems. Routing the IP The biggest task of the TCP/IP was how to get one's data to a destination. For example, you telling your browser to go to www.stuff.com. There is a lot more to the inner workings of the internet than just saying ok, I will head over to www.stuff.com. www.stuff.com is just a mask for an IP address, which in this case it being 64.49.213.239. Now this number is kept in a very large database on various super computers named "domain name" servers. With this number, it can very quickly locate where to send the information. Now you could always skip the domain name servers by typing in the address of the website, and have it go straight to it, but it's far easier to type www.stuff.com than a series of numbers.