REQUIREMENT FOR DATA COMMUNICATION:
Data communication and networking plays a significant role to perform some tasks.
Flow control of data:
In order to handle fast data flow which is sent from transmitter to receiver we require some data flow control mechanism while making agreement between two communicating devices.
Transmission system utilization:
To make tranmission channel usage more efficient while sharing information between two communcating devices we require transmission system utilisation.
Signal Generation:
Communicating devices should capable of generating signal and receiving of signals from transmitter.
Addressing:
If we want to share information between more than two devices source needs to provide its correct identity,in order to send the information to correct destination with the help of addressing.
Errror detection and correction:
While communicating between two devices the transmitted signal gets distored because of some intermediate devices. This errors in the transmitted signal is corrected at the receiver by using some error detection and correction codes.
Error detection methods: Parity checking, LRC, VRC, CRC etc.,
Error correction methods: Hamming codes, ARQ etc.,
Routing:
Router are used to send data to the destination.
PROTOCAL AND ITS TERIMINOLOGY:
Protocal:
Protocal may be defined how the communication will take place, what is communication and when communication should done. Some of key elements of protocal are:
syntax:
The word syntax refers to format or way of representing the data and meaning the order in which they are presented. Let us consider a example of simple protocal which defined first 8 bits for address of the sender, last 8 bits for receiver adress and rest of the bits for message itself.
semantics:
The term semantics is defined as meaning of section of bits, for example the identification of final destination of the message.
timing:
Timing terminology is important to determine when the data should be sent and how fast it should be sent.