Computer communications and networking

Question 1

What is a network?

Answer 1

A collection of connected computers plus their peripherals

Question 2

What is a device on a network called?

Answer 2

Node

Question 3

What is a LAN?

Answer 3

Local area network

Question 4

What is a WAN?

Answer 4

Wide area network

Question 5

Advantages of a LAN

Answer 5

• Makes data sharing easier
• Makes backups easier
• Computers are easily updated/reconfigured
• Computers can be monitored easily
• Users can communicate with each other

Question 6

Disadvantages of a LAN

Answer 6

• Specialist staff needed for maintenance
• Network problems could affect all users
• Security may be a problem because data is accessible from many places

Question 7

Differences between a LAN and WAN

Answer 7

• A LAN is confined to one site

- A LAN is owned and maintained by a single organisation but a WAN may not

Question 8

What is a network interface controller (NIC)?

Answer 8

A device that generates and receives suitable electrical signals. It holds the MAC address of each node.

Question 9

What is a MAC address?

Answer 9

Media access control address.

Allows a node on a network to be identified.

Question 10

What are fibre-optic cables?

Answer 10

Cables that transmit data using light waves

Question 11

What is a network hub?

Answer 11

Hardware that connects many network devices together into a single network segment.

A signal arriving at one is transmitted to all others

Question 12

What are switches? (No, not the lightbulb switches)

Answer 12

Devices that connect multiple network segments or devices.

Messages are only sent to the intended device

Question 13

What is the difference between hubs and switches?

Answer 13

Hubs transmit a message to all devices connected to it

However
Switches transmit a message to an intended device

Question 14

What are bridges?

Answer 14

Devices that connect more than one network together

Question 15

What are wireless access points?

Answer 15

Devices often connected to a router which allow a connection to a LAN without the need for cables

Question 16

What features do wireless access points have to protect them from security risks?

Answer 16

• encryption
• hiding their broadcast identities
• allowing access to only certain MAC addresses

Question 17

What is a router?

Answer 17

A device that receives data in the form of packets and forwards them to their destination.

Question 18

What is a client-server network?

Answer 18

Where one or more servers provide services to many client machines where the users work

Question 19

What is a server?

Answer 19

Computers that handle network functions

Question 20

Types of servers

Answer 20

• database server
• file server
• mail server
• print server
• web server
• gaming server

Question 21

What is a peer-to-peer network?

Answer 21

Where each computer in the network carries out the needs of the user as well as carrying out network functions

Question 22

Disadvantages of peer-to-peer networks

Answer 22

• maintenance is more difficult than with a client-server network
• security is poor
• tend to be slow due to the amount of multitasking

Question 23

Advantages of a peer-to-peer networks

Answer 23

• easy to set up

- files can be shared directly between users without the need to go through web servers

Question 24

What is the advantage of a client-server network?

Answer 24

The network functions are handled by dedicated machines and clients can provide for the immediate needs of the users

Question 25

What is a network topology?

Answer 25

The layout of the network components; cabling and position of the nodes

Question 26

What does a bus topology look like?

Answer 26

The computers and other devices are attached to a single backbone. [INSERT BUS TOPOLOGY DIAGRAM]

Question 27

Advantages of a bus topology

Answer 27

- easy to set up | - cheap

Question 28

Disadvantages of a bus topology

Answer 28

- problems with the backbone can bring the whole network down - can only cover a limited distance - many data collisions can slow the network down

Question 29

What does a star topology look like?

Answer 29

Client machines are connected to a central hub or switch which is usually connected to a server. [INSERT STAR TOPOLOGY DIAGRAM]

Question 30

Advantages of a star topology

Answer 30

- robust - problems with a connection do not affect the whole network - fewer data collisions than bus so faster

Question 31

Disadvantages of a star topology

Answer 31

- needs more expertise to maintain | - can be expensive to set up - more network hardware and software needed

Question 32

What does a ring topology look like?

Answer 32

Data passes through each node, carried in data units called tokens

Question 33

Advantages of a ring topology

Answer 33

- very fast - no collisions

Question 34

Disadvantages of a ring topology

Answer 34

- problems with the backbone can bring the whole network down - data passes through every node - network vulnerable to malfunctions

Question 35

What is a protocol?

Answer 35

A set of rules that covers data communications Allows different networks and devices to talk to each other

Question 36

What is the de facto standard for data transmission over the Internet?

Answer 36

Transmission Control Protocol/Internet Protocol | TCP/IP

Question 37

What is a host?

Answer 37

A computer system that is accessed remotely and holds data or other facilities such as web servers

Question 38

What are packets?

Answer 38

Collections of data forming part of a message

Question 39

What is IP concerned with?

Answer 39

The construction of packets

Question 40

What is TCP concerned with?

Answer 40

The connection of hosts

Question 41

What is packet switching?

Answer 41

Packets from a particular message may take different routes according to availability and traffic conditions, and form a complete message at the receiving end

Question 42

What is the advantage of packet switching?

Answer 42

It improves the reliability of sending messages because of one route is down or congested, another can be found

Question 43

What is an IP (Internet Protocol) address?

Answer 43

A 32-bit number so computers can be identified on a network

Question 44

What is static addressing?

Answer 44

Permanently allocated IP addresses

Question 45

What is dynamic addressing?

Answer 45

IP addresses that can be changed- a computer may not always have the same IP address

Question 46

What is a MAC (Media Access Control) address?

Answer 46

A unique number number stored in each NIC so it can be used to inset icy a device on a network