Edexcel GCSE Computer Science (1CP2) Exam Questions

• C 32 (1)
• The only correct answer is C. The correct answer is 32.
• A is not correct because 4 is the number of groups of numbers in an IPv4 address
• B is not correct because 8 is the number of bits in each group of an IPv4 address
• D is not correct because 128 is the number of bits in an IPv6 address

• A LAN (1)
• The only correct answer is A. The correct answer is LAN (Local Area Network).
• B is not correct because a PAN connects devices around one person over a short range
• C is not correct because a VPN is a secure private connection made over a public network, not a network covering one building
• D is not correct because a WAN connects networks over a large geographical area

• C It is owned by the organisation that uses it (1)
• The only correct answer is C. The correct answer is that a LAN is owned by the organisation that uses it.
• A is not correct because connecting devices in different countries is a characteristic of a WAN
• B is not correct because a LAN covers a small geographical area
• D is not correct because a LAN can use wired or wireless connections

Award one mark for any of the following up to a maximum of two marks:

• A home network (1)
• A school network / a network within a school (1)
• An office network / a network within one business building (1)
• A hospital network (1)
• A hotel network (1)

Allow a named organisation on a single site/premises, e.g. one shop, one café (1)

Do not accept the internet.

Do not accept an organisation with offices/branches in different countries / a university with campuses in different cities.

Do not accept 'LAN' / 'local area network' on its own.

Do not accept 'a network' with no context.

Award one mark for any of the following up to a maximum of two marks:

• A block/unit/chunk of data (1)
• A piece of a file/message (1)
• Sent/transmitted across a network/the internet (1)
• Contains a header with the destination/source IP address (as well as the data) (1)
• Can be routed/forwarded by routers using the destination IP address (1)

Allow 'unit' on its own for the first mark

Do not accept 'data' on its own

Do not accept a header/destination IP address on its own without identifying a unit/block of data

Do not accept 'a connection/cable between computers'

Do not accept MAC address for the addressing point

Award one mark for any of the following up to a maximum of two marks:

• POP3 / Post Office Protocol version 3 (1)
• IMAP / Internet Message Access Protocol (1)

Allow POP.

Allow IMAP4.

Do not accept SMTP, as it is used to send email.

Award one mark for any of the following up to a maximum of two marks:

• A unique identifier/address/number (1)
• Given to/identifies a device/computer on a network/the internet (1)
• Used to route/send data (packets) to the correct destination (1)
• Assigned to a device when it connects to a network/the internet (1)

Allow 'number' for 'identifier/address/number' when the answer also says it is given to/identifies a device on a network.

Do not accept a domain name/web address (e.g. bbc.co.uk) or a MAC address.

Award up to two marks for a linked description such as:

• Each IP address is unique (1) so data is sent to the correct device and not to any other device (1)
• The IP address identifies the device on the network (1) so that routers can forward packets towards it (1)
• The IP address shows which network a device is on (1) so routers can direct packets towards that network (1)
• A device needs an IP address (1) to send and receive data across the internet (1)

Do not accept MAC addresses or 'physical address'.

Do not award credit for responses about how an IP address is assigned.

Award up to two marks for a linked description such as:

• Provides the protocols used by applications (1) so a web browser can use HTTP/HTTPS or an email client can use SMTP/IMAP (1)
• Prepares/creates the data produced by the application (1) and passes it down to the transport layer (1)
• Selects the correct protocol for the application being used (1) so the receiving application can understand the data (1)

Do not accept responses about routing packets/IP addresses; these relate to the internet layer.

Do not accept naming a protocol without describing the purpose of the application layer.

Do not accept generic statements that the layer 'sends data' or 'connects to the network' without a linked development.

Indicative content

Characteristics of a WAN

• A WAN covers a large geographical area, as the hotels are in different countries.
• A WAN is formed by connecting two or more networks together, so the hotels' separate networks are joined to make the company's WAN.
• A WAN uses infrastructure that is owned by a third party, such as a telecommunications company, rather than by the company itself.
• The internet is the largest and best known WAN.

How the hotels' networks are connected

• Each hotel's own network is connected to the WAN so that its computers can reach the central booking database.
• Data between the hotels travels over links provided by the telecommunications company, not over cabling laid by the hotel company.
• A WAN can join sites in different countries, which a network in one hotel could never do on its own.

Benefits

• Every hotel reads and updates the same central booking database, so a room booked in one hotel is immediately shown as unavailable in all the others.
• Head office can send price changes and other updates to all 40 hotels at once.
• Staff in different hotels can communicate, for example by email or video conferencing.
• The company does not have to install and maintain its own cabling between the countries.

Drawbacks

• The company depends on the telecommunications company, so if a link fails that hotel loses access to the booking database.
• Renting the links across countries is expensive and is an ongoing cost for the company.
• Data travelling over links the company does not own is at more risk of interception.
• A WAN link is usually slower than the hotel's own network, so large files take longer to transfer.
• Managing one network spread across different countries is more complicated than managing one hotel's network.

Levels

• Level 0 (0 marks): No rewardable content.
• Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
• Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
• Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Level 3 answers must cover the characteristics of a WAN, how the hotels are connected, and at least one benefit and one drawback.

Do not accept 'a WAN is just a bigger LAN' without reference to connecting networks over a large distance.