Network Topology

Bus, Ring, and Star Topologies

I. Topology

A. What is a topology?

1. It refers to the arrangement of computers, cables and other items.

a. There are two different topologies – physical and logical.

2. There are four different types of topologies.

a. Bus

b. Ring

c. Star

d. Tree

3. These topologies can be mixed with one another.

b. For example: bus-star network, known as a backbone.

II. Bus Topology

A. What is a bus topology?

1. All the devices are connected to a single central cable, called the bus or backbone

a. All bus networks use backbones to connect to all devices

b. Functions as a way of shared communication that devices

will tap or attach themselves to using an interface connector

c. If the backbone cable fails, the entire network is unusable

2. It consists of a main cable (also could be known as a linear cable), which has a ‘terminator’ at each end

3. The linear cable has three different nodes connected to it

a. File server

b. Workstations

c. Peripherals

B. What uses a bus topology?

1. Ethernet

a. “ThinNet” and “ThickNet” were popular Ethernet cabling options many years ago

2. LocalTalk

C. Bus topologies are relatively inexpensive

D. They are easy to install, when concerned with small networks

1. Bus networks work best with a limited number of devices

2. Performance bugs will result if there are too many computers

E. What are the advantages?

1. Easy to connect a computer to a linear bus network

2. Requires less cable than say a star topology

a. Cabling costs stay at a low because of the “common trunk”

D. What are the disadvantages?

1. If there is a break in the main cable, entire network will shut off

a. It is difficult to even identify the problem in the main cable

b. No central distribution exists, so it’s difficult to...