Mar 11
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What is metropolitan area network?
A Metropolitan Area Network (MAN) is a large computer network that spans a metropolitan area or a campus. Its geographic scope falls between a WAN and LAN. MANs provide Internet connectivity for LANs in a metropolitan region, and connect them to wider area networks like the Internet
A metropolitan area network (MAN) is a bigger version of Local area network (LAN). It might cover a group of nearby corporate offices or a city. It might be either private or public network. A MAN can support both data and voice, and might even be related to the local cable television network. A MAN just has one or two cables and does not contain switching elements, which sent packets over one of several potential output lines. Not having to switch simplifies the design. Architecture of the DQDB (Distributed Queue Dual Bus) metropolitan area network consists of two unidirectional buses (cables) to which all the computers are connected. Each bus has a head-end, a device that initiates transmission activity. Traffic that is destined for a computer to the right of the sender uses the upper bus. Traffic to the left uses the lower one.
A key aspect of a MAN is that there is a broadcast medium to which all the computers are attached. This greatly simplifies the design compared to other kinds of networks.
Metropolitan Area Network(MAN) is a computer networks usually spanning a campus or a city, which typically connect a few local area networks using high speed backbone technologies. A MAN often provides efficient connections to a wide area network (WAN). There are three important features which discriminate MANs from LANs or WANs:
- The network size falls intermediate between LANs and WANs. A MAN typically covers an area of between 5 and 50 km range. Many MANs cover an area the size of a city, although in some cases MANs may be as small as a group of buildings.
- A MAN (like a WAN) is not generally owned by a single organization. The MAN, its communications links and equipment are generally owned by either a consortium of users or by a network service provider who sells the service to the users.
- A MAN often acts as a high speed network to allow sharing of regional resources. It is also frequently used to provide a shared connection to other networks using a link to a WAN.
MAN adopted technologies from both LAN and WAN to serve its purpose. Some legacy technologies used for MAN are ATM, FDDI, DQDB and SMDS.
- ATM – Asynchronous transfer mode is a switching technique for telecommunication networks
- FDDI – Fiber Distributed Data Interface provides a 100 Mbit/s optical standard for data transmission in a local area network that can extend in range up to 200 kilometers or 124 miles
- SMDS – Switched multi megabit data service was a connectionless service used to connect LANs, MANs and WANs to exchange data.
- DQDB – a distributed-queue dual-bus network is a distributed multi access network. It supports integrated communications using a dual bus and distributed queuing, provides access to local or metropolitan area networks, and supports connectionless data transfer, connection-oriented data transfer, and asynchronous communications, such as voice communications.
