SLR 1.5 Network topologies, protocols and layers

Question 1

Name three common network topologies

Answer 1

1. star
2. mesh
3. partial mesh

Question 2

Which common network topology is easiest to set up?

Answer 2

star

Question 3

Which common network topology is most resistant to hardware faults?

Answer 3

mesh (full mesh)

Question 4

Why is a partial mesh network topology favoured over a full mesh?

Answer 4

it is cheaper to install

Question 5

when a wireless network is set up the administrator sets a channel to be used. State what must happen for two devices to communicate via this wireless network

Answer 5

they must be on the same channel

Question 6

A device on a wireless network has poor access to the router. Other than a hardware fault state two possible causes of the poor connection.

Answer 6

1. interference between the signal from the device and another device on an adjacent channel (bleed over)
2. poor wifi signal strength due to distance
3. poor wifi signal due to obstruction

Question 7

state what is meant by the term encryption

Answer 7

• plain text is turned into cipher text
• a key is used to change the data
• data is changed so that it is unreadable without a key

Question 8

Explain what is meant by the term “ethernet”

Answer 8

• A standard for networking technologies used on wired Local Area Networks..
• A physical and data link layer set of protocols.
• The method by which data is sent down cables / error checked.

Question 9

What does CSMA/CD stand for?

Answer 9

Carrier Sense Multiple Access / Collision Detection

Question 10

How does a message get sent over ethernet?

Answer 10

• Data is split into frames.
• Each frame has a number of data bits for a particular purpose
• Frames are transmitted from the device to a switch and on to other switch(es) or device(s)
• The receiving device stitches the frames back together to assemble the original data

Question 11

What are ‘ethernet cables’?

Answer 11

ethernet cables are Unshielded Twisted Pair (UTP) cables with standard connectors on them (e.g. RJ45).

Question 12

Where are ethernet cables used?

Answer 12

They are the standard connections between devices such as routers, switches and computers on a Local Area Network (LAN)

Question 13

What does POP stand?

Answer 13

Post Office Protocol

Question 14

What is POP used for?

Answer 14

Post Office Protocol is used by email clients to retrieve email from a mail server.

Question 15

What does IMAP stand for?

Answer 15

Internet Message Access Protocol

Question 16

What is IMAP used for?

Answer 16

Internet Message Access Protocol is used by email clients to retrieve email from a mail server, and to manage remote mail boxes.

Question 17

What does SMTP stand for?

Answer 17

Simple Mail Transfer Protocol

Question 18

What is SMTP used for?

Answer 18

Simple Mail Transfer Protocol sends mail to a mail server.

Question 19

State what is meant by the term ‘layering protocols’

Answer 19

• Dividing the complex task of networking into smaller, simpler tasks.
• The hardware and/or software for each layer has a defined responsibility.

Question 20

Explain how packet switching works, stating the names of the protocols used

Answer 20

• TCP splits the data into packets.
• IP routes the packets between routers from source to destination.
• Each packet can take a different route.
• TCP sequences the packets when they arrive at their destination.