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

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 explanation such as:

• The router reads the destination IP address (1) so it knows which network/device the packet is for (1)
• The router looks up the destination IP address in its routing table (1) to find the next router/route for the packet (1)
• The router forwards the packet to the next router (1) that leads towards that IP address / is on the best route (1)

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

Do not accept MAC address - routers use the IP address to route packets between networks.

Do not accept 'it finds the exact device' without saying how the router uses the address, e.g. routing table/next router.

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

• Routers can forward the packet towards its destination (1) because they read the destination IP address in the packet header (1)
• The packet is delivered to the correct device (1) because the receiving device compares the destination IP address with its own IP address (1)
• Each packet can take a different route (1) because routers use the destination IP address to choose the next router (1)
• The packet can be passed on by each router in turn (1) because the destination IP address shows which network the packet is for (1)

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

Statements such as 'so it reaches the right destination' or 'so routers know where to send it' earn the first mark only; do not award the second mark unless the reason says that the address is read from the packet header and used to forward the packet.

Do not accept 'so it knows where it came from' as this describes the source address, not the destination address.

Do not accept 'so it gets there faster' without a linked reason.