What is a Network Topology?
In communication networks, a topology is a usually schematic description of the arrangement of a network, including its nodes and connecting lines. There are two ways of defining network geometry: the physical topology and the logical (or signal) topology.
The physical topology of a network is the actual geometric layout of workstations. There are several common physical typologies, as described below and as shown in the illustration.
In a star network each device on the network has its own cable that connects to a switch or hub. A hub sends every packet of data to every device, whereas a switch only sends a packet of data to the destination device.
In a ring network each device (workstation, server, printer) is connected to two other devices - this forms a ring for the signals to travel around. Each packet of data on the network travels in one direction and each device receives each packet in turn until the destination device receives it.
In a bus network all the workstations, servers and printers are joined to one cable (the bus). At each end of the cable a terminator is fitted to stop signals reflecting back down the bus.
Pros and Cons of each Topology
- it is very reliable – if one cable or device fails then all the others will continue to work
- it is high-performing as no data collisions can occur
- it is expensive to install as this type of network uses the most cable (network cable is expensive)
- extra hardware is required (hubs or switches) which adds to cost
- if a hub or switch fails, all the devices connected to it will have no network connection
- it is easy to install
- it is cheap to install, as it doesn't require much cable
- if the main cable fails or gets damaged the whole network will fail
- as more workstations are connected the performance of the network will become slower because of data collisions
- every workstation on the network "sees" all of the data on the network – this is a security risk
Switch/ Switch Cabinet
A network switch (also called switching hub, bridging hub, officially MAC bridge) is a computer networking device that connects devices together on a computer network, by using packet switching to receive, process and forward data to the destination device.
A server is a computer program or a machine that waits for requests from other machines or software (clients) and responds to them. A server typically processes data. The purpose of a server is to share data or hardware and software resources among clients.
A printer is a piece of hardware for a computer. It allows a user to print items on paper, such as letters and pictures. Mostly a printer prints under the control of a computer. Many can also work as a copying machine or with a digital camera to print directly without using a computer.
Switch/ Switch Cabinet
Wireless Access Point
In computer networking, a wireless access point (WAP) is a networking hardware device that allows wireless devices to connect to a wired network using Wi-Fi, or related standards.
An electronic device which is capable of receiving information (data) in a particular form and of performing a sequence of operations in accordance with a predetermined but variable set of procedural instructions (program) to produce a result in the form of information or signals.