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About the Project
A computer network allows sharing of resources and information among interconnected devices. In the 1960s, the Advanced Research Projects Agency (ARPA) started funding the design of the Advanced Research Projects Agency Network ARPANET for the United States Department of Defense. It was the first computer network in the world. Development of the network began in 1969, based on designs developed during the 1960s
Purpose
Computer networks can be used for several purposes:
• Facilitating communications: Using a network, people can communicate efficiently and easily via email, instant messaging, chat rooms, telephone, video telephone calls, and video conferencing.
• Sharing hardware: In a networked environment, each computer on a network may access and use hardware resources on the network, such as printing a document on a shared network printer.
• Sharing files, data, and information: In a network environment, authorized user may access data and information stored on other computers on the network. The capability of providing access to data and information on shared storage devices is an important feature of many networks.
• Sharing software Users connected to a network may run application program on remote computers.
• Information preservation.
• Security.
• Speed up. What is a Network?
A network is a set of devices connected by media links. A node can be a computer, printer or any other device capable of sending and receiving data generated by other nodes on the network.
Network
The links connecting the devices are often called communication channels.
NETWORK CRITERIA:-To be considered effective and efficient a network must meet a number of criteria. The most important of these are performance, reliability and security.
1. PERFORMANCE:-Performance can be measured in many ways, including transit time and response time.
 Transit time:-It is amount of time required for a message to travel from one device to another.
 Response time:-Response time is the elapsed time between an inquiry and a response.
The performance of a network depending on a number of factors including the number of users , the type of transmission medium, the capability of the connected hardware and the efficiency of the software.
• Number of users:-Having a large number of concurrent users can slow response time in a network not designed to coordinate heavy traffic loads. The design of a given network is based on an assessment of users that will be communicated at any one time.
• Type of transmission medium:-The medium defines the speed at which data can travel through a connection(the data rate).Today’s networks are moving to faster and faster transmission media, such as fiber – optic cabling. A medium that can carry data at 100 megabits per second is 10 times more powerful than a medium that can carry data at only 10 megabits per second.
• Hardware:-The type of hardware included in a network in a network affects both the speed and capacity of transmission.
• Software:-The software used to process data at the sender, receiver and intermediate modes also affects network performance. Well designed software can speed the process and make transmission more effective and efficient.
Performance is often evaluated by to network matrices:-throughput and delay. We often need more throughputs and less delay try to send more data to the network, we may increase the delay because of traffic congestion in the network.
• Throughput: - It is the total output of a network is known as the throughput.
• Delay: - The time lack behind while completing the task is called as delay.