What is Transmission Control Protocol. Services provided by TCP. Feature of TCP.

Transmission Control Protocol ( TCP)

TCP is process- to- process protocol service. It creates virtual connection between two TCP's to send data. TCP uses flow and error control mechanism at the transport lavel. In short TCP is a connection oriented reliable transport protocol. 

TCP Services:

Process to process communication:

• Like UDP (User datagram protocol) TCP provides process- to- process communication uning port numbers.

There are some list of well-known port numbers:

• Stream delivery service:

Unlike UDP, TCP is a stream oriented protocol. TCP allows the sending process to deliver data as s stream of bytes and allows the receiving processes to obtain data as a stream of bytes. TCP creates an environment in which two processes seem to be connected by a imaginary "tube" that carries thair data accross the interner. The sending process produces stream of bytes and the receiving process consumes them.

• Sending and receiving buffers:

Because the sending and the receiving process may not write or read data at the some speed. TCP means buffers for storage . The sending buffer and the receiving buffer. One for each direction.

• Segments:

Since the IP layer is the service provider for TCP later can not be sent as a stream of beats. It needs to be sent in packets. At the transport layer TCP groups a number of bytes together into a packet called a segment. 

• Full duplex communication:

TCP offers full duplex service. In which data can flow in both directions at the same time.

• Connection oriented service:

TCP is a connection oriented service. The connection establishment between two TCP's is not a physical connection. It is a virtual connection. 

• Reliable service:

TCP is a reliable transport protocol. It means an acknowledgement mechanism to check the safe and sound arrival of data.

TCP features:

Numbering system:

Data being transmitted in segment in TCP, but the segment header is not having any field as segment number. Instead there are two field called the sequence number and the acknowledgement number.

Flow control:

TCP provides flow control. The receiver of the data controls the amount of data that are to be sent by the sender.

This is turn to prevent the receiver  from being over whelmed with data. The numbering system to allows TCP to use a byte oriented flow control. 

Error control:

To provide reliable service TCP implications an error control mechanism. Although error control considers a segment as the unit of data for error detection. Error control is byte oriented.

Congestion control: 

TCP takes into account congestion in the network. The amount of data sent by a sender is not only controled by the receiver, but is aloso determined bt the level of congestion in the network.