Networks and Topologies - Paper 1

Question 1

Define network

Answer 1

A network is multiple computers or other electronic devices connected for the purpose of communication.

Question 1

Compare LANs and WANs.

Answer 1

LANs are geographically confined to one building or site. WANs are spread over a wide geographical area.
LANs are owned and maintained by the organisation. WAN hardware is owned and maintained externally.

Question 2

List some factors that affect network performance.

Answer 2

• Number of devices on the network
• Bandwidth of the transmission medium
• Type of network traffic
• Network latency
• Number of transmission errors

Question 3

Define bandwidth

Answer 3

Bandwidth is a measure of the amount of data that the medium can transfer over a given period of time.

Question 4

Give a typical maximum bandwidth for twisted copper wire.

Answer 4

10Gbps

Question 5

Give a typical maximum bandwidth for fibre optic cable.

Answer 5

100Gbps

Question 6

Give a typical maximum bandwidth for home Wi-Fi.

Answer 6

600Mbps

Question 7

Give a typical maximum bandwidth for workplace Wi-Fi.

Answer 7

6Gbps

Question 8

Define latency

Answer 8

Network latency is a measure of how long it takes a message to travel from one device to another across a network.

Question 9

Define server

Answer 9

A server is a computer that manages and stores files, or one that provides services to other computers on the network.

Question 10

Define client

Answer 10

A client is a computer that relies on other computers (servers) to provide and manage data. The computer a person uses on a network is a client.

Question 11

Define peer

Answer 11

Peers store their own files, which can be accessed by other peers on the network. Therefore, a peer is both a client and a server.

Question 12

List some types of servers and their functions.

Answer 12

• File servers hold and maintain user files
• Application servers allow programs to be run over a network
• Web servers hold and share web pages
• Print servers manage printing across a network
• Mail servers handle emails between users

Question 13

What hardware is needed to connect a stand-alone computer to a network?

Answer 13

• Wired or wireless Network Interface Card/Controller (NIC)
• Wired or wireless transmission medium
• Connection point eg router, hub, switch, Wireless Access Point (WAP)

Question 14

What is the difference between a hub and a switch?

Answer 14

Unlike a hub, a switch records which computers are connected to which ports. When traffic is received, the switch forwards the traffic to its intended recipient only.

Question 15

How can a LAN be connected to the internet?

Answer 15

Through a router, which contains a modem.

Question 16

What is the Internet?

Answer 16

Conceptually, the internet is a worldwide collection of computer networks. The term ‘internet’ refers to the network infrastructure, not the content stored on it.

Question 17

What is the Domain Name Service (DNS)?

Answer 17

The DNS is a collection of Domain Name Servers - these take a domain name and looks up its equivalent network address.

Question 18

What is Internet hosting?

Answer 18

Hosting is the storing of files and data on a web server. The web server is referred to as a host.

Question 19

What is the Cloud?

Answer 19

The cloud is a generic term for remotely accessed storage. This storage is accessed through the internet.

Question 20

Give some advantages of using the Cloud.

Answer 20

• You can access files from any location or any device, so long as an internet connection exists.
• Access can be granted to another user so they can remotely access your data.
• Reduced need to make backups - cloud storage services back up the data for you.

Question 21

Give some disadvantages of using the Cloud.

Answer 21

• There is no guarantee that someone else is not accessing your data.
• There is no guarantee that your data is being backed-up.
• Access to data is only possible with an internet connection - no connection means no access to data.

Question 22

What has the Cloud evolved to mean?

Answer 22

In recent years, the cloud has also become a term for internet-based
software facilities. These facilities usually offer limited versions of popular software such as word processors, spreadsheets and presentation software.

Question 23

Give some disadvantages of a star topology.

Answer 23

• The whole network fails if the switch fails as no node can communicate.
• A wired star topology requires plenty of cable - in a large network this can be expensive.

Question 23

Give some advantages of a star topology.

Answer 23

* Each node is separately connected, therefore a failure of one node or its link, (transmission media), does not affect any other nodes. * New nodes can be added to the network simply by connecting them to the switch. * Star networks tend to have higher performance as a message is passed on to its intended recipient only.

Question 24

Give some advantages of a mesh topology.

Answer 24

* Messages can be received more quickly if the route to the intended recipient is short. * Messages should always get through as they have many possible routes on which to travel. * Multiple connections mean (in theory) that no node should be isolated. * Multiple connections mean each node can transmit to and receive from more than one node at the same time. * New nodes can be added without interruption or interfering with other nodes.

Question 25

Give some disadvantages of a mesh topology.

Answer 25

* Full mesh networks can be impractical to set up because of the high number of connections needed. * Many connections require a lot of maintenance.

Question 26

What differentiates a full mesh from a partial mesh?

Answer 26

With a full mesh, each node is directly connected to every other node. This enables a message to be sent along many individual routes.