Network Topology

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Overview

CraigNDave

https://www.youtube.com/watch?v=Fzho2mQQEuU&list=PLCiOXwirraUDvVsza-xO2mMwW9QBIa_FG&index=0

Computer Science Tutor

https://www.youtube.com/watch?v=iiU06wkTAuY&list=PL04uZ7242_M6O_6ITD6ncf7EonVHyBeCm&index=28

TRC PowerPoint

Network Topology

Star Topology

StarNetwork svg.png

Nodes are connected to a host computer or hub that controls communication between devices. the hub or host computer regenerates any signal that it receives and passes it on. Only the intended recipient computer acts on the message.

All nodes have independent connections to the host. A cable failure on one branch of the network will continue to function normally and the failure will be easy to isolate.

Advantages Disadvantages
· Adding new devices is easy and doesn't disrupt the rest of the network. · It requires a lot of cables.
· There are no data collisions. · It is expensive to install.
· There is less traffic on the network. · Needs professionals to maintain and up keep.
· A cable failure on one branch of the network will be easy to isolate.


Bus Topology

BusNetwork svg.png

When the bus (or line) topology is used each workstation is connected to a single cable (or backbone) which links all of the workstations.

The servers are connected to the main bus for data distribution to all the workstations.

Data can be transmitted in either directed along the main cable and workstations can communicate with other workstations.

A range of peripherals can also be connected to the main bus for shared usage. This could be a printer for example.

Advantages Disadvantages
·Is cheaper to install as it used the least cable as the cost of network cabling (particular fibre optic), and the cost of the network cable installation can be significant ·If there is heavy traffic the system performance will fall off dramatically
. ·Data collisions due to shared cable
. .Problems can be difficult to isolate


Data Collisions - CSMA/CD

CSMA/CD stands for Carrier Sense Multiple Access/Collision Detection. It is the protocol for carrier transmission access in ethernet networks. If two devices try to send a frame at the same time, a collision occurs and the frames are discarded. Each devices then waits a random amount of time and retries until the transmission is successfully sent.

Logical Bus Topology

A network could be wired using a star topology, but could act like a bus topology if all data traffic is sent to all machines.

Revision Questions

Question 1

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Question 2

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Question 3

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Question 4

1. what is the difference between a physical and logical topology:

A logical, is how the node seems connected to the network, and a physical is how it is connected with wires
Correct
A physical is how the node seems connected to the network, and a logical is how it is connected with wires
Incorrect

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Question 5

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Question 6

1. What is a star topology?

All nodes are connected to each other.
That is a mesh topology
All nodes are connected by one wire.
That is a bus topology.
All nodes are connected to a central switch or hub.
Epic.
The nodes are arranged in a star shape.
Bruh.

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Question 7

1. What is a bus topology?

Uses may cables to transmit data
This is incorrect, a bus topology uses a single main cable as a backbone
Uses one main cable as a backbone to transmit data
This is correct
Connected devices in a network where each workstation has a dedicated cable to a central computer or switch
This is a star topology. A bus network uses one main cable as a backbone to transmit data
A wire with a bus in it
This is very wrong, a bus topology uses a single main cable as a backbone to transmit data

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Question 8

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Question 9

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Question 10

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Question 11

1. Which one of these is an advantage of star topologies?

Adding new devices is easy and doesn't disrupt the rest of the network.
Correct answer
It requires a lot of cables.
The correct answer was "Adding new devices is easy and doesn't disrupt the rest of the network."
It is expensive to install.
The correct answer was "Adding new devices is easy and doesn't disrupt the rest of the network."
Needs professionals to maintain and up keep.
The correct answer was "Adding new devices is easy and doesn't disrupt the rest of the network."

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Question 12

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