telephone lines but with limited distance also limited on the number of computer that can be attached to a single LAN. LAN can be owned or controlled by a single person.
WAN
The wide area network that spans a relatively large geographical area. A wide area network consists of two or more LANs. Computers connected with this type of network are often connected through public networks such as the telephone system or even satalite. WAN operates under collective or distributed ownerships and management unlike LAN. The largest WAN is the Internet.
MAN
Metropolitan area network spans several sites across a city. MAN falls between LANs and WANs. MAN is not generally owned by a single organisation, MAN has a high speed network which allow sharing of regional resources similar to a large LAN, it is also frequently used to provide a shared connection to other networks using a link to a WAN.
CAN
Campus area network the computers within a limited geographic area such as a campus or military base. This is a small and private network.
Topologies
In networking, the term topology refers to the layout of connected devices on a network. A network topology is the way that the computers are physically connected to each other to form a network. People tend to think of a topology as a network’s “shape”.
The shape does not describe the actual physical layout of the devices on the network. For example the computers on a home LAN may be arranged in a circle, but it is highly unlikely to find an actual ring topology there.
There are basic network topologies like bus, ring, star, mesh and tree.
The college uses software called ‘Novell’ which runs on the service through a WAN. The cabling it uses for this type of connection is called ‘Intranet’ the intranet uses the same technology and protocols as the Internet but is restricted to certain users. The cabling is called category 5. For example a big UK company like Superdrug, may have an Intranet in their main offices that is only available to employees of Superdrug.
Star
Star network has a central connection called a hub or switch. Devices connect to the hub or switch with unshielded twisted pair (USP) Ethernet. Star networks are used in many homes. Star networks requires a lot of cable, failure in star network cable will take down one computer’s network access and not the entire LAN only if the hub fails the entire network fails.
Ring
In a Ring network every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction either clockwise or counterclockwise, a token is passed from computer to computer. Failure in any cable or device breaks the loop and can take down the entire network. No server is needed which reduces cost and management but if one computer goes down then the whole network goes down, because the packet/frame needs to pass through each computer to get to its destination. For example if a packet of information is required from station A at station C, the packet goes through station B so it can check if any of the information is required for it, and then it passes the packet onto station C. faults in this type network can be difficult to locate because the problem could be located anywhere in the ring or stations.
Bus
Stations are connected via their own cable to a central cable. The cable has an end piece that returns the signal at either end of a bus is a terminator which is a resistor. The resistor is connected on the ends of the cable to provide a load for the circuits that attach to the bus in each node. The location where the node is connected to a bus is called a “tap” The signal does not go through each station in turn as in the ring topology but does travel down the central backbone cable with the address of the intended station within.
Tree
A tree topology combines characteristics of linear bus and star topologies. It consists of groups of star-configured workstations connected to a linear bus backbone cable. Tree topologies allow for the expansion of an existing network, and enable schools to configure a network to meet their needs.
Mesh
In a mesh topology, each computer on the network has redundant data paths The mesh topology provides fault tolerance-if a wire, hub, switch, or other component fails, data can travel along an alternate path. A diagram of a mesh network looks like a fishing net. A mesh topology is most often used in large backbone networks in which failure of a single switch or router can result in a large portion of the network going down.
Switch
A Network switch is a computer networking device that connects network segments. It uses the logic of a network bridge but allows a physical and logical star topology. It is often used to replace network hubs. A switch can connect ethernet, token ring, fibre channel or other types of packet switched network segments together.
Hub
A hub is a common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. It serves as communication wiring point to help information flowing through one central location to any other computer on the network. It is the central part of the star topology.
Router
Routers are very similar to hubs in that they allow connections of shared communication between different computer equipment. Computers attached to the shared routers can access the same printers, files, or an internet connection. In addition, network routers add a layer of protection from malicious programs.
Conclusion
In conclusion although we need all the above technology for the setup of networks we still need software like Novell, cables, connectors and network cards. There are some advantages in having a network in that you save by users sharing expensive peripheral devices like lasers and printers. Networks allow us to stay in touch with people next door and all over the world without leaving our homes whethers its LAN, MAN, WAN or CAN which allows businesses and government organisations to share important information.
