A Level Computer Science (A2) chapter 2: Communication and internet technologies MCQs with answers
By Team Megalecture · Updated 4 Nov 2026
42 exam-style questions on Communication and internet technologies, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
Ten Communication and internet technologies questions with answers
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
1. When a message is sent from one host to another, each layer of the sending host's protocol stack adds its own information to the data. What is this information called?
A
a header
B
a key
C
a checksum table
D
an address bus
Show answer
Answer: A. Each layer wraps the data from the layer above with its own header (encapsulation). The receiving host's layers remove the headers in reverse order.
2. Which is a benefit of circuit switching?
A
the links are shared efficiently between many different users
B
the connection can be set up instantly, with no delay at all
C
if one link fails, the data is sent by another route instead
D
the data arrives in order at a constant rate
Show answer
Answer: D. The reserved path gives a steady rate and no reordering, which suits real-time speech. Sharing links and re-routing around failures are features of packet switching.
3. Which is a benefit of packet switching?
A
the packets always arrive in the order they were sent
B
if one route fails, packets can be sent by another route
C
a dedicated line is reserved for the whole communication
D
there is no need for a header on each packet
Show answer
Answer: B. Packets are routed independently, so the network can avoid failed or busy links and share its capacity. Packets may arrive out of order, so a header with a sequence number is required.
4. A router forwards a packet from one network to another. What is the highest layer of the TCP/IP suite at which the router normally needs to examine the packet?
A
Application
B
Transport
C
Internet
D
Link
Show answer
Answer: C. The router reads the destination IP address in the IP header to choose the next hop, and IP belongs to the Internet layer. It does not need the port numbers of the Transport layer or the data of the Application layer.
5. A voice call is made over a packet-switched network. Which problem needs to be dealt with for the call to sound clear?
A
the call using a dedicated line
B
packets arriving late or out of order
C
the message being sent without a header
D
the packets all having to take the same route
Show answer
Answer: B. Speech needs a steady stream, but packet delay varies with the route and congestion, so voice-over-IP software must buffer and reorder the packets. A dedicated path is circuit switching.
6. Which is an advantage of using BitTorrent rather than a single server to distribute a large file to many users?
A
the load is spread across the peers, so no server is overloaded
B
the file is always downloaded in one single piece from a single source
C
only one computer needs to hold a copy of the whole file
D
no user needs an internet connection to be able to download
Show answer
Answer: A. Each peer both downloads and uploads pieces, so more peers give more capacity to supply the file. This is the opposite of a client-server model where all requests hit one server.
7. Which is a function of the Transport layer?
A
dividing the data into segments and using port numbers
B
choosing the route for each packet across the internet
C
converting frames into signals that are put on the cable
D
providing the protocols such as HTTP for the browser
Show answer
Answer: A. The Transport layer (for example TCP) splits data into segments, numbers them and uses port numbers to direct data to the correct application. Choosing routes is done by the Internet layer.
8. Six packets of one message arrive at the destination in the order 3, 1, 2, 6, 4, 5. How does the receiver rebuild the message?
A
it asks the router to send the whole of the message again from the start
B
it discards the message because the order is wrong
C
it uses the sequence numbers to put the packets in order
D
it puts the packets in the order that they arrived in
Show answer
Answer: C. Each packet carries a sequence number. The receiving host uses these to reorder the packets, so a different arrival order is not an error.
9. Which pairing of protocol and layer of the TCP/IP suite is correct?
A
TCP: Link layer
B
HTTP: Transport layer
C
IP: Internet layer
D
IMAP: Internet layer
Show answer
Answer: C. IP addresses and routes packets at the Internet layer. TCP works at the Transport layer, and HTTP and IMAP work at the Application layer.
10. Which is an advantage of implementing protocols as a stack of layers, each with its own function?
A
every layer can send data directly to the layer that is two below
B
one layer can be changed without changing the other layers
C
all the layers share the same header information
D
the data no longer needs to be split into packets
Show answer
Answer: B. Each layer only uses the services of the layer below and provides services to the layer above through a defined interface, so its internal method can be altered independently.
Communication and internet technologies: questions students ask
How many Communication and internet technologies MCQs are there?
42, each with the answer and a short explanation, across 2 topics: Protocols, Circuit switching, packet switching. Every chapter test draws ten of them, so you can take it many times.
Is the A Level Computer Science (A2) chapter 2 test free?
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
How is the chapter test marked?
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
