Computer Networks

Data link layer is divided into two sub layer: 1)       DLC 2)       MAC DLC: it stands for data link control. It deals with the procedure for communication between node to node communications. It includes flow control, error control and framing. 1)       Framing: Framing in the data link layer separate the message from source to destination by adding a sender address. The destination address defines where the packet has to go. Frame size:   frame can be of fixed or variable size.   In fixed size frame there is no need to defining the boundary of frame, the size itself can be used as delimiter. In variable size there is need of a way for defining the end of one frame and the beginning of next frame. For this [purpose two approaches are used: 1)       Character oriented     2) Bit oriented. Character oriented:   in character oriented framin...

Computer Networks: Amplitude Modulation (AM), Frequency Modulation (FM) and Phase Modulation (PM)

Computer network    A collection of computing devices that are connected in various ways in order to communicate and share resources. Usually, the connections between computers in a network are made using physical wires or cables. The generic term node or host refers to any device on a network data transfer rate.   The speed with which data is moved from one place on a network to another Data transfer rate is a key issue in computer networks. Two computers are said to be connected if they interchange information. Components of Network The following are components of network: 1)       Sender: device which send the data and information. 2)       Receiver: device which receive the data. 3)       Communication channel: medium by using which data transfer is done between sender and receiver. 4)       Protocols: set of rules and regulations. Computer Networ...