Essentially a network is a group of computers (or other devices) connected together, either by a cable or wireless. There are three common types of network:
LAN is a local Area Network, usually limited to a home or a small office. A Local area network usually connect devices inside a home, or small office. Network coverage is limited. All devices are connected to router. Connected either via a cable or wireless. Internet signals restricted to the inside the house.
MAN is a Metropolitan Area Network, a larger network than the LAN, connecting a small geographical region. It has less coverage than a WAN. It allows multiple devices to connect and communicate across a small geographical area. Unlike a LAN it is not restricted to one building, but is restricted by distance.
WAN is a Wide Area Network, connecting a much larger geographical region. Typically consisting of a number of interconnected LANs. A Wide Area Network connects devices across the world. A WAN is not restricted by distance. WANs are connected via internet, or sometimes via telephones connection.
Networks are physically represented by topology.
What is topology?
It is the way computers or network hardware are arranged in the design of the network. There are number of topologies being used.
Some of these are
A bus topology is a network in which each computer and network devices are connected to a single cable. This is also referred to as a backbone.
• It works well for a small network.
• It is very simple topology to implement, and allows you to position your device in a linear fashion.
• Uses less cables than alternating topologies.
• It can be hard to find where an issue may be.
• If a cable is damaged, the networks fail.
• Additional devices may slow the network.
• Terminators are required for both ends of the main cable.
A star topology is the most commonly used topology. In Star topology all devices are connected to a central device. This is called a switch. A hub used to be another central device, but these are now obsolete. The device in the center act as a server and the device connected are clients.
• If one computer on a network fails the rest of network continue its function normally.
• Easy to manage a network through a central switch or hub.
• Easy to add another computer.
• Network performance depend upon how powerful the central device is.
• If the central device fails the entire network fails.
• Can be costly to implement.
It is a computer network configuration where the devices are connected to each other in a circular shape. Each packet is sent around a ring until it reaches the final destination.
• All traffic flows in one direction which means the packet can’t collide.
• Additional PC’s/ devices can be added easily.
• No central networking device is needed.
• Expensive to install and maintain.
• The entire networks is damaged if one device fails.
• This network is slower than others as data has to pass throughout each device.
In Mesh all devices are connected to each other. They also have additional links to improve performance and to lower the risk of damage to the network.
• The network can withstand a lot of data, simultaneously.
• If one device fails the network remains unaffected.
• The network can be easily expanded.
• Very expensive to build.
• Difficult to maintain.
• A lot of spare connections may never be required, this creates redundancy.