Computer Network Networking Concepts Process of exchanging data

Computer Network

Networking Concepts • • Process of exchanging data or information between two devices via some form of transmission medium For data communication to occur, the communicating devices should be part of a communication system made up of a combination of hardware and software. The hardware involves the sender and receiver devices and the intermediate devices through which the data passes. The software involves certain rules which specify what is to be communicated, how it is to be communicated and when. It is also called as a Protocol.

Communication Model

Communication Model Data communication Consist of Source- Generates the data to be transmitted Transmitter- Converts the data into signals Transmission System -Carries the data Receiver - Converts the received signal to data Destination - Takes the incoming data

Communication Model Some of the Key tasks to be performed by a Communications System are: Transmission system utilization: Efficient use of transmission facilities Addressing: A source system must indicate the identity(or address) of the intended destination. Interfacing: A device must interface with the transmission system in order to communicate. Routing: A specific route through this network must be chosen. Signal generation: communicating device must be able to generate and receive these signals Recovery: To resume activity at the point of interruption or at least to restore the state of the system.

Communication Model Some of the Key tasks to be performed by a Communications System are: Synchronization: Unless the receiver and transmitter are in Synchronization the receiver will not be able to make sense out of received signals Message formatting: An agreement between two parties as to the form of the data to be exchanged or transmitted Exchange management: Both the transmitter and receiver should adhere to some common convention about the format of data, amount of data that can be sent at a time. Security: Only the intended receiver actually receives the data and the receiver of data may wish to be assured that the received data have not been altered in transit Error detection and correction: Transmitted data is prone to error. Either it is because of distortion in the transmission medium leading to misinterpretation of signal or errors introduced by the intermediate devices. Network management: Needed to configure the system, monitor its status, react to failures and overloads, and plan intelligently for future growth.

Simplified network model Data communication takes place between two devices that are directly connected by some form of point-to-point transmission medium. Sometimes, it is impractical ØThe devices are very far apart ØThere is a set of devices, each of which may require a link to many of the others at various times. The solution to this problem is to attach each device to a communications network like Wide Area Network (WAN) or Local Area Network(LAN).

Simplified network model