All machine based communications must follow certain set of rules for exchange of data between nodes connected to a network. The rules to send and receive data are called protocols. These rules are defined in the network software. A protocol defines;
Which is communicated?
How it is communicated?
When it is communicated?
Elements of Protocol:
1. Syntax:
Syntax refers to the format or structure of data. The protocol accepts the data according to the predefined format. For example, a protocol may expect the format of data as;
First 8-bits of the stream to be the address of header.
Second 8-bits of the stream to be the address of receiver.
Rest of the stream to be the actual data.
2. Semantics:
Semantic means meaning. Semantics refers to the meaning of each section of the bits stream. It includes: how is a particular pattern of bits to be interpreted, and what action is to be taken based on that interpretation.
3. Timing:
Timing refers to:
When data should be sent?
How fast it can be sent?
Functions of Communication Protocol:
The data transmission software or protocols perform the following functions for the efficient and error free transmission of data.
Data Sequencing: The function of a protocol to divide the long message into smaller packets of fixed size that are to be transmitted for error free data transmission, is called Data Sequencing.
Data Routing: The function of a protocol to find the most efficient path or route between the sender and the receiver before sending the data is called Data Routing.
Flow Control: The function of a protocol to control the rate of data transmission from the sender to the receiver is called Flow Control. It regulates the process of sending data between fast sender and slow receiver.
