Information And Technology

INFORMATION AND TECHNOLOGY RAVIRAJ S. WADE MMS – 1 DIV – B ROLL NO. 716

LAN-MAN-WAN Networking is done to connect the computing hardware such as computers. Organization which runs on basis of data ex. Banks need to be connected to each other for sharing the data. Depending on there area or spread they we have different types. When we talk about the area networks we have originally 3 classes i.e. LAN MAN & WAN. These are the basic types of networks and all others have emerged from them. These classes have various parameters such as range of network, strength, usage, hardware, etc. Let us take the information on these basic types of network

1)LAN (local area network) A local area network (LAN) is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport. The defining characteristics of LANs, in contrast to wide-area networks (WANs), include their usually higher data-transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines. Definition: A local area network (LAN) supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home. A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LANs, and to the Internet or other WAN. Most local area networks are built with relatively inexpensive hardware such as Ethernet cables, network adapters, and hubs. Wireless LAN and other more advanced LAN hardware options also exist. Specialized operating system software may be used to configure a local area network. For example, most flavors of Microsoft Windows provide a software package called Internet Connection Sharing (ICS) that supports controlled access to LAN resources.

The term LAN party refers to a multiplayer gaming event where participants bring their own computers and build a temporary LAN. Examples: The most common type of local area network is an Ethernet LAN. The smallest home LAN can have exactly two computers; a large LAN can accommodate many thousands of computers. Many LANs are divided into logical groups called subnets. An Internet Protocol (IP) "Class A" LAN can in theory accommodate more than 16 million devices In addition to operating in a limited space, LANs are also typically owned, controlled, and managed by a single person or organization. They also tend to use certain connectivity technologies, primarily Ethernet and Token Ring. Although switched Ethernet is now the most common data link layer protocol and IP as a network layer protocol, many different options have been used, and some continue to be popular in niche areas. Smaller LANs generally consist of one or more switches linked to each other—often with one connected to a router, cable modem, or DSL modem for Internet access. Larger LANs are characterized by their use of redundant links with switches using the spanning tree protocol to prevent loops, their ability to manage differing traffic types via quality of service (QoS), and to segregate traffic via VLANs. Larger LANS also contain a wide variety of network devices such as switches, firewalls, routers, load balancers, sensors and so on.[9] LANs may have connections with other LANs via leased lines, leased services, or by 'tunneling' across the Internet using VPN technologies. Depending on how the connections are made and secured, and the distance involved, they become a Metropolitan Area Network (MAN), a Wide Area Network (WAN), or a part of the internet.

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2)MAN (metropolitan area network) A MAN is a collection of LANs within the same geographical area, for instance a city. If your business has multiple offices throughout a town or city and you would like to be on the same network, it will require a MAN. A MAN is usually not privately owned by your business, and access to it is usually gained through a telecommunications network provider who sells the service to the users. As name suggests it generally covers cities and towns. Range is around 50 kms. The medium used is optical fibre or cable. Message routing is faster than LAN. A MAN is optimized for a larger geographical area than a LAN, ranging from several blocks of buildings to entire cities. MANs can also depend on communications channels of moderate-to-high data rates. A MAN might be owned and operated by a single organization, but it usually will be used by many individuals and organizations. MANs

might also be owned and operated as public utilities. They will often provide means for internetworking of local networks. Metropolitan area networks can span up to 50km, devices used are modem and wire/cable Some technologies used for this purpose are ATM, FDDI, and SMDS. These older technologies are in the process of being displaced by Ethernet-based MANs (e.g. Metro Ethernet) in most areas. MAN links between LANs have been built without cables using either microwave, radio, or infra-red laser links. Most companies rent or lease circuits from common carriers due to the fact that laying long stretches of cable can be expensive.DQDB, Distributed Queue Dual Bus, is the Metropolitan Area Network standard for data communication. It is specified in the IEEE 802.6 standard. Using DQDB, networks can be up to 30 miles (50km) long and operate at speeds of 34 to 155 Mbit/s. Several notable networks started as MANs, such as the Internet peering points MAEWest, MAE-East, and the Sohonet media network.

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3) WAN (wide area network) Definition: A WAN spans a large geographic area, such as a state, province or country. WANs often connect multiple smaller networks, such as local area networks (LANs) or metro area networks (MANs). The world's most popular WAN is the Internet. Some segments of the Internet, like VPNbased extranets, are also WANs in themselves. Finally, many WANs are corporate or research networks that utilize leased lines. WANs generally utilize different and much more expensive networking equipment than do LANs. Key technologies often found in WANs include SONET, Frame Relay, and ATM. Wan is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries [1]). Less formally, a WAN is a network that uses routers and public communications links [1]. Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs) which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well-known example of a WAN is the Internet. WANs [a] are used to connect LANs and other types of networks together, so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connections from an organization's LAN to the Internet. WANs are often built using leased lines. At each end of the leased line, a router connects to the LAN on one side and a hub within the WAN on the other. Leased lines can be very expensive. Instead of using leased lines, WANs can also be built using less costly circuit switching or packet switching methods. Network protocols including TCP/IP deliver transport and addressing functions. Protocols including Packet over SONET/SDH, MPLS, ATM and Frame relay are often used by service providers to deliver the links that are used in WANs. X.25 was an important early WAN protocol, and is often considered to be the "grandfather" of Frame Relay as many of the underlying protocols and functions of X.25 are still in use today (with upgrades) by Frame Relay. Academic research into wide area networks can be broken down into three areas: Mathematical models, network emulation and network simulation. Performance improvements are sometimes delivered via WAFS or WAN optimization.

LAN vs MAN vs WAN LAN • • • • • • •

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Typically connects computer in a single building or campus. Developed in 1970s. Medium : optical fibres, coaxial cables, twisted pair, wireless. Low latency (except in high traffic periods). High speed networks (0.2 to 100 Mb/sec). Speeds adequate for most distributed systems Problems : Multi media based applications Typically buses or rings.Ethernet, Token Ring

MAN • • • • • •

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Generally covers towns and cities (50 kms) Developed in 1980s. Medium : optical fibres, cables. Data rates adequate for distributed computing applications. A typical standard is DQDB (Distributed Queue Dual Bus). Typical latencies : < 1 msec. Message routing is fast.

WAN • • • •

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Developed in 1960s. Generally covers large distances (states, countries, continents). Medium : communication circuits connected by routers. Routers forwards packets from one to another following a route from the sender to the receiver. Storeand-Forward Typical latencies : 100ms 500ms. Problems with delays if using satellites. Typical speed : 20 - 2000 Kbits/s. Not (yet) suitable for distributed computing.

New standards are changing the landscape.