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TCP is the abbreviation for Transmission Control Protocol, which is the system of addressing and transmitting information over a network to its intended destinations.[1] TCP is the main basis of the Internet and it is the language which majority of the world’s networked computers use to communicate with each other.[2]

TCP/IP was developed in the 1970s, and was used as the protocol standard for ARPANET in 1983.[3]

How It Works

Whenever an HTML file is sent through a Web server, the TCP program layer in the server divides the file into many packets of information and forwards them to the IP program layer individually. Though there is same destination IP address for each packet, chances are they may get routed differently through the network. On the other end, which is the client program in the computer, the TCP reassembles the individual packets and forwards them to the consumer as a single file when they arrive.[4]

TCP is the transport layer protocol, which is used by applications which require a guaranteed delivery. It is a kind of sliding window which deals with handling of both retransmissions as well as timeouts. The TCP is responsible in establishing full duplex virtual connection between the endpoints. Each of these endpoints is defined by the Internet Protocol or IP address and a TCP port number. The TCP operation is executed as a finite state machine. The number of bytes of data which can be sent before confirmation is determined by the window size.[5]

Use of TCP

TCP is used as the de facto standard through which data is transferred on all networks. TCP is also supported by all network operating systems that use independent protocols such as Netware.[6] TCP also provides a great deal of functionality to IP service, which is layered into the following:

  • Reliable Delivery: In TCP, sequence numbers are used to designate which data has been transmitted and received. If there is any loss of data, the TCP transmits the data all over again.
  • Streams: The TCP data is well organized into a stream of bytes, similar to a file. The datagram nature of the network is highly concealed. The TCP also consists of a mechanism known as the urgent pointer which lets out of band data to be flagged.
  • Flow control: TCP also coordinates traffic and manages its data buffers. This guards against the overflow of the buffers.
  • Network Adaptation: TCP dynamically learns all the delay characteristics of a network and then adjusts its own operation to enhance throughput without overloading the network.[7]

Relation of TCP and IP

The IP receives the application program provided by the TCP through its communication services at an intermediate level. This basically means that whenever an application needs to transfer any large data through the IP, it sends a request to the TCP and allows it to handle the details of the IP transfer. In short the problems in the IP are detected by the TCP and retransmit the lost packets. The TCP also rearranges the order in which the packets were sent and minimizes the congestions in the network. This in turn helps to reduce the reoccurrence of the problem. [8]