1.3 Computer networks, connections and protocols

Question 1

LAN

Answer 1

Local Area Network - Small geographic area. All the hardware for the Lan is owned by the organisation using it. Wired with UTP, fibre optic cable or wireless using routers and Wi-Fi access points.

Question 2

WAN

Answer 2

Large geographic area. Infrastructure is hired from telecommunication companies who own and manage it. Connected with telephone lines, fibre optic cables or satellite links.

Question 3

Client-server network

Answer 3

A client makes requests to the server for data and connections. A server controls access and security to one shared file store. A server manages access to the internet, shared printers and email services. A server runs a backup of data.

Question 4

Peer-to-peer network

Answer 4

All computers are equal. Computers server their own files to each other. Each computer is responsible for its own security and backup. Computers usually have their own printer.

Question 5

Wireless access point

Answer 5

A networking hardware device that allows a Wi-Fi device to connect to a wired network.

Question 6

Router

Answer 6

A router sends data between networks. It is needed to connect a local area network to a wide area network. It uses the IP address on a device to route traffic to other routers.

Question 7

Switch

Answer 7

A switch sends data between computers on a local area network. It uses the NIC address on a device to route traffic.

Question 8

NIC

Answer 8

Network Interface Card - A computer hardware component that connects a computer to a computer network.

Question 9

Transmission media

Answer 9

The physical media over which data is transmitted, e.g. Twisted copper cable, fibre optic cable etc.

Question 10

The Internet

Answer 10

The internet is a worldwide collection of interconnected computer networks. It is an example of a WAN, albeit the largest one that exists.

Question 11

DNS

Answer 11

Domain Name System - The Internet’s equivalent of a phone book. They maintain a directory of domain names and translate them to Internet Protocol (IP) addresses. This is necessary because, although domain names are easy for people to remember, computers or machines access websites based on IP addresses.

Question 12

Hosting

Answer 12

Websites stored on dedicated servers. Reasons include: Websites need to be available 24/7. Accessed by thousands of users at a time. Strong protection from hackers. They need an IP address that doesn’t change.

Question 13

The Cloud

Answer 13

Remote servers that store data that can be accessed over the internet.

Question 14

Web server

Answer 14

A program that uses HTTP(Hypertext transfer Protocol) to serve the files that form web pages to users, in response to their requests, which are forwarded by their computers’ HTTP clients. Dedicated computers and appliances may be referred to as Web servers as well.

Question 15

Client

Answer 15

A client can be thought of as computing device which requests or is using the services from some remote / connected server.

Question 16

Network topology

Answer 16

The physical or logical arrangement of connected devices on a network e.g. Computers, switches, routers, printers, servers etc.

Question 17

Star topology

Answer 17

Computers connected to a central switch. If one computer fails, no others are affected. If the switch fails, all connections are affected.

Question 18

Mesh topology

Answer 18

Switches (LAN) or routers (WAN) connected so there is more than one route to the destination. E.g. The internet more resilient to faults but more cable needed.

Question 19

Advantages of ‘The Cloud’ are:

Answer 19

Advantages: Access anytime, anywhere from any device. Automatic backup. Collaborate on files easily. No hardware required.

Question 20

Name a few types of servers that have different services

Answer 20

Web server, database server, DNS server, email server, file server etc.

Question 21

Disadvantages of ‘The Cloud’ are:

Answer 21

• Lack of control. Handing over of data and information.
• Bandwidth problems. All depends on speed of connection.
• Relies on a stable internet connection.

Question 22

Advantages of a Star topology:

Answer 22

• Cheaper than mesh topologies.
• One cable breaking will only affect its corresponding node.

Question 23

Disadvantage of Star topology:

Answer 23

• The switch is a huge point of failure - if it breaks then all computers lose their connection to the rest of the network and the internet.

Question 24

Advantage of Mesh topology:

Answer 24

If you get a break in a cable, traffic can be rerouted via another cable.

Question 25

Disadvantage of Mesh topology:

Answer 25

Very expensive as lots of cabling and switch hardware is needed.

Question 26

Advantages of Partial Mesh topology:

Answer 26

The same benefit as a full mesh network to a slightly lower extent. Cheaper than a full mesh network.