Network Topologies by Phoebe Barnett

Star Topology

phoebe_mb — 2015-11-11 09:36:05 UTC

In a star network layout, each workstation is connected by its own cable directly to the server. Star networks are usually the layout of choice in schools and offices because they tend to be the most reliable of the topologies.

Advantages:

star networks are very reliable - if one connection fails, it does not affect other users
very few data collisions as each workstation has its own cable to the server
good security - no workstation can interact with another without getting through the server first

Disadvantages:

the most expensive network layout to install because of the amount of cables needed
installing the network usually needs experts to set it up
extra hardware such as hubs and switches may be needed
if the server crashes or stops working then nobody will be able to access their files or use the network

Ring Topology

phoebe_mb — 2015-11-11 09:36:15 UTC

In a ring network layout, all of the computers are connected to one another in a circle. The data passes from one computer to the next one and then all the way around the ring layout until it reaches the destination computer.

Advantages:

transmission of data is fairly simple as it only travels in one direction
no data collisions
extra computers can be added easily with little effect on performance - although you have to shut down the network to be able to do this

Disadvantages:

if a single machine is switched off, the network doesn't work
if a cable breaks, the network doesn't work
data must pass through every computer until it reaches its destination - this can make it slower than other network layouts
if there are any problems with the network, the cause can be difficult to identify

Bus Topology

phoebe_mb — 2015-11-11 09:36:20 UTC

This is the simplest methods of connecting computers. A single cable joins all of the workstations, printer, file server and other components together. At each end of the bus is a 'terminator'. This is a piece of hardware which prevents signals bouncing back and forth (echoes).

Advantages:

easy to install
easy to add extra workstations
signals can be sent either way
uses less cable than a star network
best choice for temporary networks
Disadvantages:
if there is a problem with the central cable, the entire network stops working
if there are a lot of workstations on the network, data can travel slowly
data collisions can happen as the network becomes busy
low security - every workstation can see all of the data in the network
limited cable length and a maximum number of workstations

Introduction

phoebe_mb — 2015-11-11 09:36:25 UTC

Once you have decided to network a number of computers together, the next decision which needs to be made is which network layout or topology would be the best to use. There are a number of different topologies to choose from, the three most popular being bus, ring and star.