MAN (Metropolitan-Area Network) is a network that is utilized across multiple buildings. A MAN is much larger than the standard Local-Area Network (LAN) but is not as large as a Wide Area Network (WAN).Thus, a Metropolitan Area Network (MAN) is a large computer network on the large geographical area that include several buildings or even the entire city(metropolis). MAN includes many communicating devices and provides the Internet connectivity for the LANs in the metropolitan area. The diameter of such a network can range from 5 to 50 kilometers. As a rule, MAN does not belong to any particular organization, in most cases, a group of users or a provider who takes charge for the service own its connecting elements and other equipment.