KALOMBO BYEMBWE SERGE

L20192E060111

 

 TCP/IP (Transmission Control Protocol/Internet Protocol)

 

TCP/IP, or the Transmission Control Protocol/Internet Protocol, is a suite of communication protocols used to interconnect network devices on the internet. TCP/IP can also be used as a communications protocol in a private network (an intranet or an extranet).

The entire internet protocol suite -- a set of rules and procedures -- is commonly referred to as TCP/IP, though others are included in the suite.

TCP/IP specifies how data is exchanged over the internet by providing end-to-end communications that identify how it should be broken into packets, addressed, transmitted, routed and received at the destination. TCP/IP requires little central management, and it is designed to make networks reliable, with the ability to recover automatically from the failure of any device on the network.

The two main protocols in the internet protocol suite serve specific functions. TCP defines how applications can create channels of communication across a network. It also manages how a message is assembled into smaller packets before they are then transmitted over the internet and reassembled in the right order at the destination address.

IP defines how to address and route each packet to make sure it reaches the right destination. Each gateway computer on the network checks this IP address to determine where to forward the message.

How TCP/IP works

TCP/IP uses the client/server model of communication in which a user or machine (a client) is provided a service (like sending a webpage) by another computer (a server) in the network.

Collectively, the TCP/IP suite of protocols is classified as stateless, which means each client request is considered new because it is unrelated to previous requests. Being stateless frees up network paths so they can be used continuously.

The transport layer itself, however, is stateful. It transmits a single message, and its connection remains in place until all the packets in a message have been received and reassembled at the destination.

Importance of TCP/IP

TCP/IP is nonproprietary and, as a result, is not controlled by any single company. Therefore, the internet protocol suite can be modified easily. It is compatible with all operating systems, so it can communicate with any other system. The internet protocol suite is also compatible with all types of computer hardware and networks.

TCP/IP is highly scalable and, as a routable protocol, can determine the most efficient path through the network.

CONCLUSION

Through TCP/IP, it is now possible to communicate reliably between software located on different computers.

TCP/IP is used for many things:

In your browser, the HTP protocol uses TCP/IP protocol to send and receive HTML pages, GIF images, JPG images and various other data.

File transfer protocol is the protocol for sending and receiving files. It also uses TCP/IP.

Your email software uses SMTP and POP3 protocols to send and receive mail. SMTP and POP3 also use TCP/IP.

Your browser (and other software) uses the DNS protocol to find the IP address of the computer based on the name of the computer (for example, from www.yahoo.com to 216.32.74.52). DNS protocol uses UDP/IP and TCP/IP as needed.

As a result, hundreds of different protocols use TCP/IP or UDP/IP.

The advantage of TCP over UDP is that TCP can provide reliable communication. The disadvantage is the need for negotiation ("Hello, are you ready to communicate?" It takes time.

If you are curious and want to see all the exchanged IP packages and their contents, you can use excellent Ethereal software (http://www.ethereal.com). The free software captures and decodes everything that goes through the network. Very instructive