1.3.1 Networks and topologies • Performance of networks

Do Now!

Network performance depends on how much data can be sent, how reliable the connection is, and how much delay builds up while data travels through the network.

Factors that affect network performance A central network cloud connected to cards for bandwidth, users, transmission media, error rate and latency. NETWORK PERFORMANCE Bandwidth how much data Users shared demand Media wired or wireless Error rate re-sent data Latency delay in delivery

Today's Big Idea

A fast network is not only about speed. Performance is affected by available bandwidth, the number of users sharing it, the transmission media being used, the connection error rate, and latency caused by delays or bottlenecks.

Bandwidth The amount of data that can be sent each second, measured in bits per second.
Error rate If data arrives wrongly, it must be re-sent, reducing performance.
Latency The delay between sending data and the device receiving it.

Activity 1: Match the Key Terms

Drag each term into the correct definition.

Bandwidth
Bit rate
Latency
Transmission media
Error rate
Number of users
Term Definition
The amount of data that can be sent successfully in a set period of time.
The unit often used to measure bandwidth, in bits per second.
The delay between data being transmitted and the device receiving it.
The method used to carry data, such as copper cable, fibre optic or wireless.
How often data transfer goes wrong and has to be re-sent.
How many devices are sharing the network at the same time.

Activity 2: Sort the Statements

Place each statement into the correct performance effect.

Changing from copper to fibre optic cable.
Reducing the number of users sharing the same bandwidth.
Using switches properly to segment traffic.
Moving closer to the wireless access point.
Too many devices using the network at once.
Wireless interference causing more transfer errors.
Long, lower-quality copper cabling.
Hardware operating at different speeds and creating bottlenecks.

Likely to improve performance

Likely to reduce performance

Activity 3: Predict the Best Explanation

Read each situation and type the network factor that best explains the problem.

Scenario 1

A classroom has 32 devices
streaming video on the same
wireless network.

Pages load slowly even though
the internet connection is working.

Scenario 2

A laptop is far from the wireless
access point and walls are
blocking the signal.

Files keep failing and have to
be sent again.

Scenario 3

Data is being transmitted, but
there is a noticeable delay
before the user sees any reply.

Some parts of the network are
slower than others.

Activity 4: Explain the Network

Use the scenario to explain which factors are affecting performance and suggest one improvement.

Task Scenario

A school computer room uses older copper cables and a wireless access point at the far end of the corridor. At break time, many students connect at once. Some devices are slow to receive data, while others keep having to re-send work.

Think about shared bandwidth, the quality of the transmission media, wireless distance from the access point, error rate, and latency caused by bottlenecks. Then suggest one clear improvement such as fibre optic cabling, better switch use, or reducing congestion.

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Create a record of your starter activity responses.