Networks

Question 1

What is a computer network?

Answer 1

A computer network is a group of computers / devices connected together,

Question 2

What are the benefits of having a computer network?

Answer 2

Makes person to person communication easier

Shared resources save money (Example: Printers)

Question 3

What is PAN?

Answer 3

PAN / Personal Area Network is a network in range of an individual person.

Example: Bluetooth

Question 4

What is LAN?

Answer 4

LAN / Local Area Network is a network that connects devices close to each other.

Example: Same house or school

Question 5

What is WAN?

Answer 5

WAN / Wide Area Network is a network over a broader geographic area.

Example: The Internet

Question 6

Name 3 ways of measuring network performance.

Answer 6

Latency - The delay (how vast signals travel)

Bandwidth

Error Rate - How often data is corrupted

Question 7

What are factors that affect network performance?

Answer 7

Whether it wired or wireless (Wired is usually faster)

Bandwidth that is shared across network (Can become congested)

Signals may be blocked

Signals at the same wireless frequency interfere (Increasing error rate)

The physical layout.

Question 8

What is a node?

Answer 8

A node is a device on a network.

Question 9

What are the benefits of star topology?

Answer 9

If one cable or device fails then other devices will be unaffected.

Cables are not shared so no data collisions.

Easy to add new devices.

Question 10

What are the negatives of star topology?

Answer 10

Expensive to install, due to lots of cabling and central device being required.

The performance of the network is limited by the performance of the central device.

If the central device fails so will the network.

Question 11

What are the benefits of bus topology?

Answer 11

Less cable is needed than other topologies.

Question 12

What are the negatives of bus topologies?

Answer 12

If the bus fails, then no devices can communicate.

When the bus is busy, data collisions occur, increasing error rate.

All devices receive all the packets, which is a security issue

Question 13

What is the difference between star topology and bus topology?

Answer 13

A star topology is where devices are connected to a central device.

A bus topology is where they connect to a single cable.

Question 14

What is a protocol?

Answer 14

A set of rules that allows two devices to communicate.

Question 15

What are the order of the protocols?

1. Data link
2. Transport
3. Application
4. Network

Answer 15

The Order Is:

Application
Transport
Network
Data Link

Question 16

What does Application Layer do in the protocol?

Answer 16

Where the network applications operate.

Example: (Web browsers, Email clients)

Question 17

What does Transport Layer do in the protocol?

Answer 17

Sets up communication between two hosts.

Splits the data packets.

Question 18

What does Network Layer do in the protocol?

Answer 18

Addresses and packages the data, then actually routes it.

Question 19

What does Data Link Layer do in the protocol?

Answer 19

Where hardware and drivers operate.

Question 20

Give 3 advantages of using a computer network rather than a standalone machine.

Answer 20

Share hardware

Share data / files

Improved communication tools

Question 21

One disadvantage of using a computer network is that there are increased security risks. Describe three other disadvantages of using a computer network.

Answer 21

Reliance on server

Network can slow down

Cabling costs

Question 22

What are the advantages and disadvantages of wireless networks.

Answer 22

Advantages:

Can use computer anywhere and not constrained by cables

Disadvantages of wireless:

Packets can be intercepted more easily than wired connections

Slower then wired

Signal can be interfered with by other electronic devices.

Question 23

What are the advantages and disadvantages of wired networks?

Answer 23

Advantages:

Has more control, security, and reliability.

Wired is faster than wireless

Disadvantages:

Cables can be difficult to organise.

Question 24

What is HTTP?

Answer 24

HTTP (Hypertext transfer protocol) is the protocol that governs communication between a web browser and the client.

Question 25

What is the difference between HTTPS and HTTP

Answer 25

HTTPS is much more secure (Secure Hypertext transfer protocol).

It is a secure way of transferring between the web browser and a server as the data is encrypted.

Question 26

What are the five email protocols?

Answer 26

SMTP (simple mail transfer protocol)

IMAP (Internet message access protocol)

TCP (Transport Control Protocol)

IP (Internet Protocol)

UDP (User datagram protocol)

Question 27

What does SMTP do?

Answer 27

SMTP sends the mail from the user onto the mail server.

Question 28

What does IMAP do?

Answer 28

IMAP retrieves the mail from the mail server to the user.

Allows access from anywhere on any device because the email remains on the server.

Question 29

What does TCP do?

Answer 29

When files are sent over they are broken into small chunks (packets).

When they arrive at the destination computer they are reassembled to the original format.

TCP controls all this

Question 30

What does IP do?

Answer 30

The internet protocol is a set of rules that govern the transmission of data across the internet

Question 31

Wat does UDP do?

Answer 31

is used as an alternative to TCP.

It improves speed by not checking for lost packets so they don’t get resent.

Mostly used for games.