Unit 3 Past Papers

Question 1

Outline why a wireless network may be less secure than a wired network.

Answer 1

wired network is only accessible with a physical cable connection and in wireless
networks signals are broadcasted outside of the building;
leaving it open to the public and potential hackers/ it is easy to intercept transmissions;

a wireless network is more open to misuse;
as network administrator cannot directly monitor a specific machine;

Question 2

Outline two features of a VPN that make it secure. (4)

Answer 2

Authentication;
Nobody outside the VPN should be able to use the VPN and affect the security of the VPN,
so only user name and password authentication is not enough;
Strong user VPN authentication uses various methods, including certificates, one-time
passwords and software tokens;

Encryption;
If data intercepted, it will not be readable; encrypting each encapsulated data packet’s content with an encryption key (the key is
shared only between the VPN’s server and clients);

Tunnelling software;
A VPN hides a user’s data by encrypting it with a tunnel created between the user’s device
and the VPN’s web server (The user then takes on the IP address of the web server (rather
than their true IP), and this leads to one advantage of a VPN (namely that a user can appear to be in a different geographic location than they are actually located in);

Multiple exit nodes;
Makes it hard to distinguish where the data sent is originated (protecting privacy);

Mark as [2] and [2]
Award [1] for a feature and [1] for a reasonable expansion,

Question 3

Explain how data is transmitted by packet switching

Answer 3

Data is organized in specially formatted units (data packets);
Each data packet contains: data, address of the sender, address of the receiver, size of
packet, sequence number, control codes, etc.; which are routed from source to destination using network switches and routers; network switches and routers determine how best to transfer the packet between a number of intermediate devices (routers and switches) on the path to its destination (rather than flowing directly over a single wire on the path to its destination); data packets are reassembled at destination;