Computer Network

This is the range of internet, it covers the entire planet.

Physical layer is the bottom layer of OSI model. It is concerned with transmitting raw bits over the communication channel.

Local Area Network is privately owned network within a single building or campus of up to few kilometers in size.

Servers are fast computers that run various software's, store and process information and also provide a human interface to the user to use the networked computers.

Session layer controls the dialogues / connections between computers.

Data link layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the Physical layer.

This is the range of Local Area Network.

Application layer interfaces directly to the users and performs common application services for the application processes.

Noise is defined as unwanted energy from sources other than the transmitter.

Delay distortions are transmission impairment communication lines have distributed inductance and capacitance, which distort the amplitude of signals and also delay the signal at different frequencies by different amounts.

Cross talk is caused due to the inductive coupling between two wires that are close to each other.

Intermodulation results from interference of different frequencies sharing the same medium.

Host-to-Host layer of TCP/IP Reference Model deals with opening and maintaining connections, ensuring that packets are in fact received.

In serial transmission, character is transmitted in a sequence over a single line.

Wide Area Network [WAN] spans a large geographical area often a continent or country.

Half duplex refers to two-way communication but in only one direction at a time.

Synchronous transmission is a type of communication in which communicating parties are live or present in the same space and time.

Asynchronous transmission refers to processes that proceed independently of each other until one process needs to interrupt the other process with a request.

Star topology is designed with each node connected directly to a central network hub.

Topology is the term used to describe the way in which computers are connected in network.

A tree topology combines characteristics of linear bus ans star topologies. It consists of group of star configured workstations connected to a linear bus back bone cable.

Ring topology is used for operation and working of LAN.

TCP, UDP protocols are used at transport layer.

Network is a group of various components together in such a way that, it is possible to distribute or collect information over the entire group.

With a star topology, expanding a network is easily done by adding another concentrator.