Edexcel GCSE Computer Science (1CP2) Exam Questions

• C Router (1)
• The only correct answer is C. The correct answer is router.
• A is not correct because a hub sends data to every device on the network
• B is not correct because a network interface card connects a device to a network
• D is not correct because a switch forwards data within a single network using MAC addresses

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

• A delay/time/lag (1)
• Between a signal/request being sent and a response/data being received (1)

Allow 'the time taken for data to travel from source to destination' for both marks.

Do not accept 'the speed at which data travels' / 'bandwidth' / 'the amount of data sent per second'.

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

• (Ethernet) cables are not affected by interference from other devices (1) so data is transferred at a consistent/steady speed (1)
• Each device has its own cable to the switch (1) so the full bandwidth is available to that device and speeds do not drop as more users join (1)
• Fibre optic cable has a higher bandwidth than a wireless link (1) so more data can be sent along the cable each second (1)
• The cable gives a direct/physical path to the switch (1) so data is less likely to be lost and resent, which would slow the transfer (1)

Do not accept responses about security, reliability or users being unable to move around, as these are not about speed.

Do not accept answers that only say a wired/cable connection is faster, or that fibre is faster, without saying why.

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

• Each router chooses the best route at the time (1) so when a route becomes busy/congested or fails, later packets are forwarded along a different path (1)
• Routers forward each packet separately (1) so the path a packet takes depends on the traffic conditions when that packet arrives (1)
• A router may send a packet to a different next router (1) if its routing table shows a better/less congested route for that packet (1)
• Traffic on the internet changes (1) so no single path is kept for the file and each packet can use whichever route is best when it is sent (1)

For both marks, the expansion must follow/associate with the statement.

Allow reference to a routing table, or to how a router decides the route, as part of the linked reason.

Do not accept 'the packets have different IP addresses' because all packets from the same file have the same destination IP address, even though their routes can differ.

Do not accept 'the internet is busy' or 'there is a lot of traffic' on its own without linking this to the router choosing a different route.

Do not accept 'different routers send the packets' on its own without a reason why a different router/route is chosen.

Do not accept an answer that only says the packets take different routes without explaining why.