A large computer network which extends to a city or to a large university campus is termed as metropolitan area network or MAN. The purpose of MAN (Metropolitan Area Network) is to provide the link to the internet in the long run. A MAN (Metropolitan Area Network) usually incorporates a number of LANs to form a network. This large network MANs (Metropolitan Area Network) backbone comprises of an optical fiber set-up.
Types of MAN (metropolitan Area Network) Technologies
Most widely used technologies to develop a MAN (Metropolitan Area Network) network are FDDI (fiber distribution data interface), ATM (Asynchronous Transfer Mode) and SMDS (switched multi megabit data service).ATM (Asynchronous Transfer Mode) is the most frequently used of all. ATM (Asynchronous Transfer Mode) is a digital data transfer technology. It was developed in 1980 to improve the transportation of real time data over a single network. ATM (Asynchronous Transfer Mode) works just like cell relay system, where data is separated in the form of fixed equal sized packets and is transferred overtime. The purpose of ATM (Asynchronous Transfer Mode) was to access clear audio and video results during a video conferencing. The attributes of ATM has enabled it to become a base of wide area data networking.
ATM (Asynchronous Transfer Mode) combines the characteristics of circuit switching and packet switching, which allows it to transfer even the real time data. FDDI is a standard for data transfer over LAN, which can be extended to the range of approximately 200kms. FDDI can help support the data transmission of many thousand users. This is the reason why it is referred to as the MAN (Metropolitan Area Network) technology. FDDI uses optical fiber for its basic infrastructure that is why it is referred to as fiber distribution data interface. When data is transferred through a connectionless service we use the technology named as SMDS. Connectionless service implies that data is transferred by storing the information in the header and it reaches its destination independently through any network. When the data is transferred using the technology of SMDS, it also forms small data packets just like in ATM. However SMDS allows the transmission of data over large geographical areas in the form of datagrams (the data packets of an unreliable data service provider). Nowadays MAN (Metropolitan Area Network) links are established using infrared and microwave signals.
How Metropolitan Area Networks (MAN) works
MAN (Metropolitan Area Network) usually falls between LAN and WAN. It is generally applied to connect geographically dispersed LANs. Therefore the goal of MAN is to develop a communication link between two independent LAN nodes. A MAN (Metropolitan Area Network) is usually established using optical fiber. The network is established using routers and switches. A switch is a port which is active in handling the filtration of data usually coming in the form of frames. Any switch acts as a dual port, at one end it is handling filtration of data and at the other end managing connections. Router is another device for facilitating the netwosrk connection. Router helps the data packets to identify the path to be taken. Hence in other words it keeps an eye on the data transfer. MAN (Metropolitan Area Network) is usually operated over an area of up to 50kms.
Advantages of MAN (Metropolitan Area Network)
MAN (Metropolitan Area Network) falls in between the LAN and WAN. It therefore increases the efficiency of handling data while at the same time saves the cost attached to establish a wide area network. MAN (Metropolitan Area Network) offers centralized management of data. It enables you to connect many fast LANs together. Telephone companies worldwide have facilitated the transfer of data with the help of an underground optical fiber network. These optical fibers increase the efficiency and speed of data transfer. The optical fibers enable you to access a speed of almost 1000mbps. If you develop a WAN of 1.45 mbps its cost is more than what it gives you. Whereas when you establish metropolitan area network it offers you the speed of 1000mbps as a whole with the lowest cost involved.