Outline two advantages of a school using a computer network.

Describe the purpose of the following hardware component of a network: Router

Describe the purpose of the following hardware component of a network: Network interface card (NIC)

Outline why protocols are necessary.

Define the term data encryption.

Evaluate the use of trusted media access control (MAC) addresses as one method of network security.

Award [4 max]
File sharing/resource sharing;
instead of using a disk or USB key to carry files from one computer to another files can be shared directly using a network/all computers in the network can share resources such as printers, scanners;

Communication;
students/teachers can communicate with people around the world via the network;

Interactive teamwork;
software (like Microsoft Office) enables many users to contribute to a document concurrently;

Flexible access;
network allows students to access files from different computers (throughout the network) (one can begin work on a project on one computer and finish up on another);

Software cost;
software products are available for networks at a substantial savings in comparison to buying individually licensed software;

Software management;
load software on the server saves time compared to installing and tracking files on independent computers/upgrades are also easier because changes only have to be done once on the file server instead of on individual computers;

Improved network security;
if the school has its own network, it can monitor network traffic / can create a security culture (everyone who has a username and password is responsible for keeping data secure);

Mark as [2] and [2].

Award [2 max]
A network router is a hardware device that is connected to multiple channels for different networks;
through an interface that is situated on each network;

Router acts as a processing unit for information packets;
it duplicates information packets for use during transmission from one network to another;

The router uses a protocol or set of rules;
to determine which information packets are to be routed to certain interfaces within the network;

Award [2 max]
Network interface cards are used to connect each computer to the network;
so they can communicate with the network router to receive information packets;

Interface cards determine the infrastructure of a local area network (LAN);
and allow all of the computers to connect to the network;

Award [2 max]
Protocols define the rules that govern network communication (for example, packet format, type and size, what happens when an error occurs, and which part of the network is supposed to handle the error and how);

Computer networks consists of various types of equipment (such as routers, switches, hubs and network interface cards) and the equipment comes from different vendors, but they must all work together or the network does not operate correctly;

Protocols work in layers (the highest being what the user sees, and the lowest being the wire that the information is transferred along) and these layers communicate with each other according to the rules (allowing communication to occur accurately and efficiently);

Award [1 max]
Data encryption refers to calculations/algorithms that transform plain text into a form that is non-readable to unauthorized parties (authorized recipient of an encrypted text uses a key and the algorithm to decrypt the data/ to transform it to the original plain text version);

Award [4 max]
Each (wireless network) adapter has a unique label called a MAC address;

Routers uses these addresses to identify/authenticate computers (routers include an option to whitelist or blacklist certain devices based on MAC addresses, so access could be restricted to any device which is not in the whitelist);

One disadvantage is that the whitelist should be amended any time a new device is purchased / when access to guests should be granted;

Also this method is useless against hackers who use programs which intercept data passing through network and report the MAC address of any device communicating on the network;

Candidates were mostly able to outline at least one advantage of a school using a computer network. Answers were usually based around file or resource sharing. However, in many cases, the second advantage outlined was also related to file or resource sharing. Very few of the other possible answers were seen.

Candidates generally found this question to be difficult and very few correct answers were seen, concerning the purpose of a router.

Candidates who achieved a mark for this question generally recognised that a network interface card was used to connect a computer to the network. Unfortunately, candidates who scored, generally only achieved a single mark, as they did not expand on their answers.

Candidates generally recognised that protocols define rules that govern network communication, but generally did not expand beyond that point, so rarely achieved two marks.

A mixed set of responses was seen for this question, in which candidates were required to define the term encryption. Candidates recognised that it was a security method but were often unable to provide sufficient detail to define clearly what it is.

Candidates generally demonstrated a good understanding of what MAC addresses are and how they can be used in network security. Most candidates scored some marks. However, responses often lacked sufficient distinct points to allow all of the marks to be awarded.