1
Explain why POP3 is less suited for users accessing email from multiple devices.
Because it downloads and (often) deletes emails from the server, so they’re not accessible on other devices.
Name one advantage BitTorrent has over FTP for distributing large files to thousands of users.
Reduces server load by sharing file pieces among peers.
What is BitTorrent?
This protocol breaks files into pieces and shares them among peers.
What happens to a circuit-switched path when one user pauses speaking?
It stays reserved and idle.
Give one modern example where circuit switching is still used.
Traditional PSTN landlines or 2G voice calls.
What is IMAP?
This protocol retrieves email without removing it from the server, allowing multiple device access.
What is TLS (or SSL)?
HTTPS uses this protocol for encryption.
In the TCP/IP model, which layer decides the next hop for a packet?
Internet Layer
Why doesn’t the Application Layer need to know about physical cables?
The Link Layer handles the physical transmission details
Which layer reassembles packets into the correct order?
Transport layer
If the Internet Layer adds the IP address, what does the Transport Layer add to make a socket?
Port number
What is one reason packets might arrive out of order?
They take different routes to the destination.
How does packet switching maintain efficiency when a network path becomes congested?
It can reroute packets via alternate paths.
If a packet is lost, which TCP/IP layer detects this and ensures it’s resent?
Transport layer
Why can two applications on the same computer use the same IP address without conflict?
Because each uses a different port number.
State 3 things done by the transport layer.
breaks data into manageable packets
adds a packet header
It handles packet loss/corruption
Why is circuit switching not used in the public internet?
It’s inefficient and requires continuous resource allocation.
4 functions of a router in packet switching
Reads packet destination address (IP address)
Can send packets from the same message down different paths.
Decides the next hop (most optimum route to the destination)
Helps connect different networks (e.g., your home network to the wider internet).
what is protocol and why do we need it?
protocol is a set of rules for successful transmission and receipt of data.
Communication protocols are necessary because:
All data is (sent and received) using the same format.
All data is (sent and received) using the same rules.
Allows communications between devices operating on different platforms.
The communication is independent of the hardware used.
The communication is independent of the software used.
why does the link layer needs to map IP addresses to MAC addresses?
Without this, your data wouldn’t know which exact device on the network to reach
Name 5 protocols in the application layer
HHTP, IMAP, POP3, SMTP, BitTorrent
explain how packet switching works
Data is divided into packets.
Each packet is given a destination address.
Packets may take different paths to the destination.
Destination device reassembles packets into the original message.
Explain terms Seeder, Leecher, Swarm, Tracker
Seeder: A peer who has the complete file and is uploading pieces to others.
Leecher: A peer who is downloading the file and may (or may not) be uploading parts they already have.
Swarm: All the peers connected for the same torrent file.
Tracker: A server that coordinates peers in a torrent swarm.
BONUS
BONUS
State 3 reasons why BitTorrent is useful
Faster downloads
No single point of failure
Efficient bandwidth use