Edexcel GCSE Computer Science (1CP2) Exam Questions

• B Router (1)
• The only correct answer is B. The correct answer is Router.
• A is not correct because a hub sends the data it receives to every device on the network
• C is not correct because a server provides services, such as web pages, to client computers
• D is not correct because a switch forwards data between the devices on one network

• B Higher data transfer speed (1)
• The only correct answer is B. The correct answer is higher data transfer speed.
• A is not correct because the 2.4 GHz band has the greater range
• C is not correct because the 2.4 GHz band passes through walls more easily
• D is not correct because the 5 GHz band does not use less bandwidth

Award one mark for:

• (Destination) IP address (1)

Allow IP address on its own (the destination is implied).

Do not accept source IP address/IP address of the sender.

Do not accept MAC address.

Do not accept domain name/web address.

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

• Files/data download/upload more quickly (1)
• More employees can use the connection at the same time without it slowing down (1)
• Web pages/streamed video load more quickly with less buffering (1)
• Video calls/conferencing run at a higher quality (1)
• Updates/backups can be completed in less time (1)

Allow 'multiple users' or 'more devices' for the shared-use point

Allow 'video streams more quickly' or 'less buffering' on their own

Do not accept lower latency, as a higher bandwidth does not reduce latency

Do not accept 'more data can be transferred per second' or 'a bigger bandwidth', as these repeat what bandwidth is

Do not accept 'more reliable' on its own, as a higher bandwidth does not make a wired connection more reliable

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

• Faster transmission speed (1)
• Higher bandwidth (1)
• Lower latency (1)
• Not affected by interference (from other devices/walls) (1)
• No blind spots/not affected by distance from the wireless access point (1)

Do not accept benefits of wireless connections, e.g. users can move around the building with their devices

Do not accept 'easier to set up' or 'does not need a password' as these are not about network performance

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 receiver can put the packets back into the correct order (1) because packets may arrive out of order/take different routes (1)
• The receiver can see if a packet is missing (1) because the sequence of numbers shows a gap (1)
• The receiver knows when the whole file has arrived (1) because the total number of packets/last packet number is known (1)

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

Allow 'so the packets can be put back in the correct order/reassembled' for the first mark, but the second mark needs the reason, i.e. packets may arrive out of order/take different routes.

Do not accept 'so the packets can be identified' without stating what the number is used for, e.g. reordering or spotting a missing packet.

Do not accept 'so the router knows where to send it' - the router uses the destination IP address, not the packet number.

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

• Splits the data/file into packets (1) so each packet can be sent separately across the network (1)
• Adds a packet/sequence number to each packet (1) so the packets can be put back into the correct order at the destination (1)
• Detects lost/missing packets (1) so they can be requested/resent (1)
• Creates a connection between the two computers/hosts (1) before the file is sent (1)

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

Allow 'segments' for 'packets' (TCP divides the data into segments, which become packets at the internet layer).

Do not accept 'sends the data/file' on its own without saying what the transport layer does to the data.

Do not accept naming TCP or a port number on its own without expansion.

Do not accept routing/addressing packets using IP addresses, which is the internet layer.

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

• Wireless signals can be blocked or absorbed by walls (1) so the data must be re-sent, which adds delay (1)
• A device further from the access point has a weaker signal (1) so data must be re-sent/transmitted at a lower rate, adding delay (1)
• Devices on a wireless network share a channel (1) so a device must wait its turn to transmit, which adds delay (1)
• Interference from other devices affects the radio signal (1) so data must be re-sent, adding delay (1)

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

Allow 'waiting to send' or 'collisions' as the delay caused by devices sharing a channel.

Do not accept 'wireless is slower than wired' on its own, as this repeats the question.

Do not accept a reason that only affects download speed/bandwidth (e.g. 'files take longer to download') without a link to delay.