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

• 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:

• (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:

• The maximum distance data/a signal can be transmitted before it becomes too weak to be received (1)

Allow 'how far a signal can travel'.

Do not accept the number of devices that can be connected to the network.

Do not accept the speed at which data is transmitted.

Do not accept bandwidth/the maximum capacity of a channel.

Do not accept latency/the delay between a signal being sent and received.

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:

• (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 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:

• 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:

• The cable provides a direct physical path to the switch/router (1) so data does not have to travel through the air where it can be delayed by obstacles such as walls (1)
• The cable is not shared with other wireless devices (1) so data does not have to wait for a free channel before it is sent (1)
• The data travels straight along the cable to the switch (1) so the time taken for it to reach its destination is short (1)

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

Do not accept 'the wired connection is faster' on its own without saying why the delay between sending and receiving is shorter.

Do not accept a definition of latency without a reason.