Networking

It is time for technological period and technical line. We are used networks for different way in different purpose. Networking as a designed to meet new people or connected together to share or exchange information and cooperate. World people are most popular about networking at that time. Simply we uses various types of networks everyday and every moment like as: when we get cash from ATM machine, or when we pick up or dialed mobile phone or land line phone, we are using some type of  networks properly. Networking is an important skill for mostly business people. In the world of computer networking is the practice of linking two or more computing device together for sharing time, sharing data. Networks are built with a mix of computer hardware and computer software. Networking functions make available the chance to expand our contact list, mostly when we create quality relationship. Networking is today considered so vital that its hard to conceive of an organization with two or more computers that would not want to connect them together. In other word network is simply collection of computers or other hardware device that are connected together, either physical or logically, using special hardware and software. Networking is the term that describes the process involved in designing, implementing, improvement, management and otherwise working with networks and network technologies. Networks consist of two or more computer that is linked in order to share source as (such as printers and CD-ROMs) exchanged files or allow electronic communication. The computers on computers on networks may be linked through cables, telephone line, radio waves, satellites or infrared light beam. In this time network are world wide and networks are everywhere. Internet has also revolutionized lives of millions in a variety of way even in the real world.

There are basic types of networks include in LAN, MAN and WAN.

Local area network (LAN): A network is said to be Local Area Network (LAN) if it is confined relatively to a small area. It is generally limited to a building or a geographical area, expanding not more than a mile apart to other computers. LAN configuration consists of:

                          A file server - stores all of the software that controls the network, as well as the software that can be shared by the computers attached to the network.

                          A workstation - computers connected to the file server (Mac or PCs). These are less powerful than the file server

                         Cables - used to connect the network interface cards in each computer.

   Metropolitan Area Network (MAN): covers larger geographic areas, such as cities. Often it is used by local libraries and government agencies often to connect to citizens and private industries.

  Wide Area Network (WAN): Typically reach across a single home, whereas wide area networks (WANs), reach across cities, states, or even across the world. It connect larger geographic areas, such as London, the UK, or the world. In this type of network dedicated transoceanic cabling or satellite uplinks may be used. The Internet is the world's largest public WAN.

Networks allow people and machines to communicate, using a number of services. The distance problem is solved by using a network, such as the telephone network with modem. Modern networks have more than the physical and the data link layers. The network layer is a set of mechanisms that can be used to send packets from one computer to another in the world. Mostly there are two type of networks:-

--packet switching:- packet switching, data packets can be carried together on the same link. They are differentiated by addressing information. Packet switching is the basis for all data networks today, including the Internet, public data networks such as Frame Relay and even ATM. Packet switches have queues.

--Circuit switching:- is the way telephone networks operate. A circuit emulates the physical signals of a direct end-to-end cable. When computers are connected by a circuit switched network, they establish a direct data link over the circuit. This is used today for modem access to a data network. Modern circuit switches are based on byte multiplexing and are thus similar to packet switches, with the main difference that they perform non-statistical multiplexing.

Physical, data link and network layers are sufficient to build a packet transport system between computers. The primary goal of the transport layer is to provide the programmer with an interface to the network. Second, the transport layer uses the concept of port. A port is an address that is used locally (on one machine) and identifies the source and the destination of the packet inside one machine. The transport layer exists in two varieties: unreliable and reliable.