• Token Ring: It was developed by IBM and standardized in IEEE 802.5. Token Ring implements a LAN using ring topology with speeds ranging from 4 to 16 Mbps.
  • Fiber Distributed Data Interface (FDDI): It is similar to Token ring and uses a dual ring topology for redundancy. The LAN is built using optical fiber cabling and provides high speed connectivity.
  • Ethernet: It is the most popular and widely deployed LAN access method. It is defined in the IEEE 802.1D standard. Ethernet network are built in star or tree topologies.

Figure 1 shows a simple Local Area Network with few hosts and servers



Figure 1

Wide Area Networks (WAN) cover a broad geographic area such as cities, country or even across continents. Wide Area Networks are used to interconnect multiple Local Area Networks that are several miles apart. Due to the long distance connectivity an organization has to purchase WAN service from a service provider or a carrier. There are several types of Wide Area Networks such as leased lines, circuit-switched networks and packet-switched networks.

A company or an organization that has to connect multiple offices that span over cities, countries or even the entire globe subscribe to WAN service from a provider, whereas Local Area Networks are owned by the organization itself and there is no need to purchase any kind of connectivity service.

Figure 2 show a Wide Area Network that connects two offices of an organization several distance apart.


Figure 2

Metropolitan Area Network (MAN) is a network that spans a larger geographical area than a LAN. It connects multiple Local Area Networks over high speed links such as fiber optic cables. A MAN can be built by a single organization to connect multiple offices spanning a few building that are not very far from each other or it might be operated as public utility.

To sum up, Local and Wide Area Network differ from each other mainly due to the area they cover and because of this there are different physical and data-link layer standards developed for each type of network. So this brings us to the end of this article where we covered some basic network concepts that are an essential part of Cisco CCNA Certification curriculum.