What is Network Scale: LAN,MAN,WAN,GAN

Networks can be classified according their scale, that is, the geographical areas which they span.  Local Area Networks (LANs) are the smallest.  They can be entirely in a single room, or expand into a group of close buildings.  Typically, the same company owns the computers and the transmission medium (e.g., the cabling.) Metropolitan Area Networks (MANs) can span widely separated buildings in a city and its suburbs.  Typically, transmission between the buildings is handled by a local common carrier - a local telephone company, usually a Bell Operating Company (BOC.)  Wide Area Networks (WANs) interconnect widely separated cities in the same country.  Typically, transmission between the cities is handled by an interexchange carrier (IXC) - a long distance telephone company. Global Area Networks (GANs) interconnect international cities, spanning the globe.  This can involve separate long distance telephone companies for each country involved. The functional distinctions between LANs, MANs, WANs, and GANs are blurring.  This is due to several factors.  The US Telecommunications Deregulation Act of 1996 allows long distance companies to enter the local telephone market, and at some point will allow the BOCs to enter the long distance market.  The emergence of global telecommunications companies means that a single common carrier can interconnect buildings anywhere on the globe.  Historically, LANs have used protocols such as IPX/SPX to transfer data, while MANs, WANs, and GANs have used other protocols, such as X.25.  LANs, MANs, WANs, and GANs are also converging this area, with WAN protocols such as TCP/IP and ATM being used on LANs.

Local Area Network (LAN)

Local Area Network A computer network geographically limited to a small area such as a room, building, or close group of buildings.

Metropolitan Area Network (MAN)

Metropolitan Area Network (MAN) A computer network connecting geographically separated sites which are located in a single metropolitan area.

Wide Area Network (WAN)

Wide Area Network (WAN) A computer network spanning two or more cities.

Global Area Network (GAN)

Global Area Network (GAN) A computer network spanning the globe.