by Dinesh Thakur Category: Computer Network

In "frequency shift keying (FSK)", the frequency of a sinusoidal carrier is shifted between two discrete values. One of these frequencies (f1) represents a binary "1" and the other value (f0) represents a binary "0". The representation of digital data using FSK is as shown in Fig. Note that there is no change in the amplitude of the carrier.

 
by Dinesh Thakur Category: Computer Network

Modem word came from the combination of two words modulator and demodulator.A modem is a hardware device that enables the computers to transmit data over cable or satellite connection.A modem converts signals between modulator and demodulator vice versa. The outgoing digital signals from a computer a modem can modulates to an analog signals and in the demodulation in reverse analog signal are converts back to a digital signal.The modems can be classified according to their characteristics as below:



 
by Dinesh Thakur Category: Computer Network

 Computer System Model

The term computer networks resulted from the 'combination of two major areas, namely computers and communications.



 
by Dinesh Thakur Category: Computer Network

A Metropolitan Area Network (MAN) covers larger geographic area such as cities or districts. By interconnecting smaller networks within a large geographic area, information is easily disseminated throughout the network. Local libraries and government agencies often use a MAN to connect to citizens and private industries. It may also connect MANs together within a larger area than LAN. The geographical limit of a MAN may span a city.



 
by Dinesh Thakur Category: Computer Network

• Hybrid networks are the networks that are based on both peer-to-peer & client-server relationship.
• Hybrid networks incorporate the best features of workgroups in peer-to-peer networks with the performance, security and reliability of server-based networks.
• Hybrid networks still provide all of the centralized services of servers, but they also allow users to share and manage their own resources within the workgroup.

 
by Dinesh Thakur Category: Computer Network

                   Point-to-point Connections

The point-to-point scheme provides separate communication channels for each pair of computers. When more than two computers need to communicate with one another, the number of connections grows very quickly as number of computer increases. Above figure illustrates that two computers need only one connection, three computers need three connections and four computers need six connections.



 
by Dinesh Thakur Category: Computer Network

Client Computer: A personal computer in networking that connects to the server and uses the network services to perform user's tasks is a client computer.



 
by Dinesh Thakur Category: Computer Network

In computer networking Switches (also called switching hub, bridging hub,and more correctly called a network switch) and Bridges are the layer 2 computer networking devices. Once the number of users began to push the limits of a single computer network segment, there was a need to create a new segment to link two computer networks together a device called bridges accomplished this. basically the bridges have 2 ports, one for each computer networks, bridges actually inspect the data that passes through them and make decisions about whether to send it to the other computer network or not. Switch takes data from one network device and forwards it to the destination node based on MAC address.



 
by Dinesh Thakur Category: Computer Network

The distinguishing feature of star topology is that all nodes are joined at a single point, as shown in Figure. This single point is called as a central node, hub, or switch, to which all other devices are attached directly, generally via UTP or STP. This topology is frequently used for networks in which control of the network is located in the central node. This method is optimal when the bulk of communication is between the central and outlying nodes. If traffic is high between outlying nodes, an undue switching burden is placed on the central node.

 
by Dinesh Thakur Category: Computer Network

     Need For Computer Networks

The term network is defined as a set of computers of different types, terminals, telephones, and other communication equipments, connected by data communication links, which allow the network components to work together. The network components may be located within a small area or spread over many remote locations. In any case, data communications hold the network together.

 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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