NETWORK PROTOCOLS
In computer networks, communication occurs between entities in different systems. An entity is anything capable of sending or receiving information. Examples include application programs, file transfer packages, browsers, database management systems, and electronic mail software.
A system, is a physical object that contains one or more entities, Examples include computers and terminals. But two entities cannot just send bit streams to each other and expect to be understood. For communication to occur, the entities must agree on a protocol. A protocol is a set of rules that govern data communication. A protocol defines what is communicated, how it is communicated, and when it is communicated. The key elements of a protocol are syntax, semantics, and timing.
Syntax
Syntax refers to the structure or format of the data, meaning the order in which they are presented. For example, a simple protocol might expect the first eight bits of data to be the address of the sender, the second eight bits to be the address of the receiver, and the rest of the stream to be the message itself.
Semantics
Semantics refers to the meaning of each section of bits. How is a particular pattern to be interpreted, and what action is to be taken based on that interpretation. For example, does an address identify the route to be taken or the final destination of the message?
Timing
Timing refers to two characteristics: when data should be sent and how fast they can be sent. For example, if a sender produces data at 100 Mbps but the receiver can process data at only 1 Mbps, the transmission will overload the receiver and data will be largely lost.
In data communication, a protocol is a set of rules that govern all aspects of information communication.
Protocols Example
There are a many standard protocols to choose from, standard protocols have their own advantage and disadvantage i.e., some are simpler than the others, some are more reliable, and some are faster.
From a user’s point of view, the only interesting aspect about protocols is that our computer or device must support the right ones if we want to communicate with other computers. The protocols can be implemented either in hardware or in software. Some of the popular protocols are:
1.TCP/IP
2.HTTP
3.FTP
4.SMTP
5.POP
6.Token-Ring
7.Ethernet
8.Xmodem
9.Kermit
10.MNP, etc.
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