TCP Features

TCP Features

TCP has several features that are briefly summarized as below

Numbering System

There are two fileds called sequence number and acknowledgement number. These two fields refer to a byte number and not segment number. 

Byte Number

TCP numbers all data bytes that are transmitted in a connection. 

When TCP receives bytes of data from a process, it store them in sending buffer and number them. 

The byte number is not ncessarily to start from 0. Instead, TCP chooses an arbitrary number between 0 to 2³²-1 for the number of the first byte.

Sequence Number

After the bytes have been numbered, TCP assigns a sequence number to each segment that is being sent. The sequence number for each segment is the number of the first byte of data carried in that segment.

Acknowledgement Number

Acknowledgement number is used to conform the bytes has received by the station.
Acknowledgement number is cumulative and defines the number of the next byte that the party expects to receive.

Flow Control

TCP Provides Flow Control, This is done to prevent the receiver from being overwhelmed with data.

Error Control

TCP implements an error control mechanism to provide reliable service.

Congestion Control

TCP takes into account of congestion in the network. The amount of data sent by a sender is not only controlled by the receiver but also determine the level of congestion if any in the network.