Edexcel GCSE Computer Science (1CP2) Exam Questions

• B Sends it on to the next router (1)
• The only correct answer is B. The correct answer is sends it on to the next router.
• A is not correct because a packet is given its number by the sending computer before it is sent
• C is not correct because packets are put back into order by the receiving computer
• D is not correct because the original file is rebuilt by the receiving computer once all the packets arrive

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

• Data travels along the cable directly to the switch on a single continuous path (1) so the time between sending and receiving the data is short (1)
• A cable is not affected by interference from other devices/wireless traffic nearby (1) so packets are not lost and resent, which would add to the delay (1)
• The switch sends the data only to the port of the correct device, not to every device (1) so the data spends less time travelling and the delay is lower (1)
• Fewer devices share a cable than share a wireless channel (1) so packets do not queue/wait before they are sent (1)

The first mark is for the way the wired connection carries the data; the second mark is for how this reduces the delay between sending and receiving.

Do not accept responses about bandwidth or the amount of data a cable can carry, as latency is the delay between sending and receiving.

Do not accept responses that confuse latency with speed/bandwidth, e.g. 'a wired connection is faster so there is less latency', unless they describe how the delay is reduced.

Do not accept answers that only say a wired connection is faster, with no link to the delay.

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

• The WAN uses leased lines rented from telecommunications companies (1) so the company pays ongoing rental charges for the connections between its offices (1)
• The WAN covers a large geographical area (1) so more cabling/equipment must be paid for to connect the sites (1)
• The WAN connects networks in different locations (1) so more hardware, such as routers, is needed at each site, which adds to purchase and maintenance costs (1)
• The WAN connects more devices/networks (1) so more money is spent on hardware and management (1)

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

The answer must relate to cost, e.g. paying rental/charges, buying more equipment or paying for maintenance.

Do not accept 'it is bigger' without saying that it covers a larger distance or that more equipment must be paid for.

Do not accept 'it is slower' as a reason for higher cost.

Do not accept 'the WAN is more complex' without expansion as to why this costs more.

Do not accept 'it uses satellites/wireless' unless linked to paying for long-distance infrastructure.