Font size
WorksheetsCambridge IGCSE Computer Science Data transmission: Data packets
Total questions: 20
Worksheet time: 7mins
What are data packets usually referred to as?
(a)
Which of the following is NOT a part of a typical packet structure?
Packet header
Payload
Packet trailer
Packet footer
Refer to the Packet structure. Which part of the packet contains the actual data being sent?
(a)
The packet header consists of which of the following? (Select all that apply)
IP address of the sending device
IP address of the receiving device
Sequence number of the packet
Size of the packet
The actual data being sent
The payload of a packet usually consists of about 64 KiB of data.
True
False
What is the main purpose of the packet trailer in a data packet?
(a)
The process of cyclic redundancy checks (CRCs) as used in packet trailers involves:
calculating a checksum value to detect errors in transmitted data
encrypting the data for secure transmission
compressing the data to save bandwidth
assigning IP addresses to packets
What does each stage in the route between computer 'A' and computer 'B' contain?
A switch
A router
A hub
A modem
Packet switching is a method of data transmission in which a message is broken up into a number of (a) .
Each packet in packet switching can be sent independently from start point to end point.
True
False
At the destination, the packets will need to be reassembled into their correct order using the information sent in the (a) .
In packet switching, what determines which route the packet needs to take at each node?
The packet size
The router
The sender
The receiver
The shortest possible path available is always selected for each packet.
True
False
Unfortunately, packets can reach the destination in a different order to that in which they were sent.
True
False
What is one benefit of packet switching?
It ties up a single communication line
It is possible to overcome failed, busy or faulty lines by simply re-routing packets
It is difficult to expand package usage
It has a low data transmission rate
Which of the following is a drawback of packet switching?
There is no need to tie up a single communication line
Packets can be lost and need to be re-sent
It is easy to expand package usage
A high data transmission rate is possible
The purpose of adding a hop number to each packet in a network is:
to prevent packets from circulating indefinitely
to increase the speed of data transmission
to encrypt the data in the packet
to identify the sender of the packet
Fill in the blank: The hop number is reduced by (a) every time it leaves a router.
According to figure, what is the hop number when a packet leaves Router 11?
(a)
Circuit switching differs from packet switching in that:
Circuit switching establishes a dedicated path for the entire communication session, while packet switching divides data into packets that take different routes.
Circuit switching sends data in packets that may take different routes, while packet switching uses a dedicated path.
Both circuit switching and packet switching use the same route for all data packets.
Packet switching establishes a dedicated path for the entire communication session, while circuit switching divides data into packets.
