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03 - Performance of Networks

1. You've probably heard people complain about the network being slow. Nothing can be done about network performance.

TRUE

FALSE

2. Many factors directly impact how fast application queries and responses will flow through the network. Which in the list is NOT a factor?

1. Network Latency 
2. Network congestion 
3. Client or Server health

All of the items in the list are potential factors in network performance

Just #3 Client or Server Health

None of these are factors

Just #1 - Network Latency

3. Bandwidth is a big factor in network performance. What is network bandwidth?

The bandwidth describes how much data can be transferred over a connection in a given time.

The bandwidth describes how big each band holding every network cable can be.

The bandwidth is simply referring to the speed that the internet travels to one's home network

The bandwidth describes the width of each 'band' (cable) that connects to each client computer

4. In the 'olden days' a non-broadband dial up modem had a bandwidth of ….

56Kbps

A dial-up modem would not have any bandwidth at all

256 Mbps

1Gbps

5. Basic copper wire based broadband (download bandwidth) has a bandwidth of:

2 to 10 Mbps

256 Mbps

56Kbps

1Gbps

6. Read the excerpt below that provides additional descriptions and see if you can fill in the blanks.

Fibre Optic Broadband has a bandwidth of 10 to 75 Mpbs; 
Ethernet wired network using Cat-5 cable  has a bandwidth 
of 10 - 100 Mbps. Ethernet wired network using Cat-6 cable
(you'll learn about this in network hardware) 
has an ____________ bandwidth of ________________

There is no such thing as Cat-6 so this question cannot be answered.

decreased / 10Mbps to 100Mbps

infinite / infinite

increase / 1 Gpbs to 10 Gpbs

7. Compared to all the descriptions and networks you've explored, what do you think the bandwidth of a wi-fi network would be?

1 - 10 Mbps with Fast Wi-Fi up to 90 Mpbs

54 - 150 Mbps with Fast Wi-Fi up to 900 Mpbs

1 - 20 Tbps with Fast Wi-Fi up to 999 Tpbs

54 - 150 Gbps with Fast Wi-Fi up to 900 Gpbs

8. Chosing a network is a matter of balancing cost and performance because …

The higher the bandwidth the lower the performance of the network.

The lower the bandwidth the greater the cost

the higher the bandwidth, (usually) the more expensive it is

the higher the bandwidth the cheaper it is

9. It is possible for even the most impressive network to slow down if enough people are using it at the same time.

FALSE

TRUE

10. The "contention ratio" is ….

The ratio of speed to bits in a network.

The ratio of users compared to the no. of computers

The ratio of bandwidth to speed

The ratio of users compared to available bandwidth

11. Assume all your neighbors are home and surfing the net on Sunday evening and most people are asleep on Monday morning 2am. When would the internet seem most responsive?

On Monday morning

It would be equally responsible on both Sunday evening and Monday morning

Sunday Evening

It would fail to work at all on Sunday evening.

12. If you were a big business that absolutely needed a reliable and fast internet connection - what could you do?

install bigger cables underneath the ground to increase the bandwidth manually

pay less money so that their bandwidth is increased

pay extra money for a low-contention ratio connection

pay extra money for a high-contention ration connection

13. A contention ration of 100: 1 would mean that…

100 users may be sharing 1 line at any given time

This is not a valid ratio as it cannot be explained.

100 lines could be being used by 100 users

1 user could be using a 100 lines at any given time

14. A 1:1 ratio would mean that only a single connection is allowed on the line. This would guarantee a constant speed at all times!

FALSE

TRUE

15. Wired networks will use Ethernet (copper) cables to carry data. They come in two main categories.

Cat-5(faster), Cat-6(slower)

Bat-1 (super fast) and Cat-2(medium level speed)

Cat-5(slower), Cat-6(faster)

Cat-1 and Mat-1

16. Fibre optic cable transfers data using light and is super fast - in fact the bandwidth is only limited by…

The strength of the sun (light source) on that particular day

the cable itself

the equipment connected to it rather than the cable itself

The speed of light.

17. Wi-fi is considered a radio technology and so its performance is affected by factor that affect radio. One of these factors is:

Choice of cable strength

Choice of colour (of the wifi radio)

Choice of Band

Choice of Yap (a type of radio signal)

18. Read the excerpt below and fill in the blanks:

Wi-Fi works in two frequency bands - one at 2.4GHz and another at 5Ghz.
A 'band' is a range of frequencies. These bands are further divided into separate 
"channels" Using separate channels is a good idea in terms of improving network 
performance because ..................................? Note: The 2.4 GHz band 
can carry several non-overlapping channels. The 5Ghz band carries many non-overlapping
channels and so has a higher capacity, but the equipment is more expensive and it has
a shorter range.

The exact number of channels is regulated by law.

it reduces the signal strength which is helpful for security and performance.

it improves performance by increasing the wi-fi signal by 1000 times

it reduces the interference caused by nearby devices

it increases the interference caused by devices which improves performance

19. In addition to the choice of band and channel which other factors from the list can affect Wi-fi network performance?

1. Radio Interference 
2. No of Radio devices in any given country 
3. Blockage by walls (thick walls and floors) 
4. Limited connections available to users.

All of the listed items

1,3,4

1 only

1 and 2

20. Fill in the blanks

Another factor in measuring network performance is how many data errors 
happen over a given time. You can think of an "error" in this regard as 
the situation caused by a binary '1' being sent; but a binary '0' 
being actually received on the other end. (or the other way round). 

There are two main reasons for this happening 


1. Heat (the weather being too hot) or Cold (extreme cold) and

2_______________.

Heavy duty nuclear weaponry and dust and fire attacks

Hackers that specialise in inverting bits and Extra bright sunshine

Interference (electric motors or power equipment) can make bits flip randomly and weak signal strength

Light rain or drizzling

21. Generally speaking, the longer the cable (the length of the cable)….the -

stronger the signal

greater the performance

weaker the radio signal

weaker the signal

22. "Latency" is a word you will hear a lot when dealing with networks. It is the technical word for…….

mechanics

love

speed

delay

23. "Latency" is much more of an issue (in terms of how far a bit has to travel) in LANS.

TRUE

FALSE

24. In a huge network, every switch, router and cable would add (delay) latency to the connection.

FALSE

TRUE

25. A high performance network should have high latency.

FALSE

True

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