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1CP2-P-7.5 Protocols and responsibilities by layer

Part 5 of 6 · 1CP2-P-7 · Embedded systems, IoT and TCP/IP

The protocol worksheet, placing each named protocol at the layer it works in and the task it exists to do.

Students will:

  • explain one advantage of HTTPS over HTTP for a submitted password
  • compare POP3 with IMAP for a user reading email on two devices
  • identify the layer Ethernet and Wi-Fi operate at
  • name the most suitable protocol for a stated task
  • explain why devices need agreed protocols to communicate at all

Inside: 6 explanation cells, 2 multiple-choice questions, 2 fill-in-the-blanks cells and 5 written answers. 20 marks, about 45 minutes.

Series: 1CP2-P-7 · Embedded systems, IoT and TCP/IP, part 5 of 6.

Shared by Coding PathwayVerified teacher

  • 15 cells
  • About 45 minutes
  • CC BY-SA 4.0
  • Shared 17 Aug 2026

Preview

The whole resource, exactly as a class sees it. Answers and marking are held back.

Protocols and responsibilities by layer

A protocol is an agreed set of rules for communication. Pearson expects the purposes of HTTP, HTTPS, FTP, POP3, SMTP and IMAP at the application layer, plus Ethernet and Wi-Fi at the link layer. A protocol name earns little unless its purpose matches the scenario.

1. Web and file protocols

  • HTTP transfers web resources between clients and servers.
  • HTTPS performs secure web communication: HTTP protected through encryption/authentication mechanisms.
  • FTP transfers files between computers.

HTTPS protects data in transit; it does not prove that all content on a website is honest or remove malware from a downloaded file.

Fill in the blanks3 marks
A browser commonly retrieves ordinary web resources using gap 1. A protected web session uses gap 2. A dedicated file transfer can use gap 3.
  • FTP
  • HTTP
  • HTTPS
  • SMTP
Written answer2 marks

Explain one advantage of HTTPS over HTTP when submitting a password.

Link protection in transit to interception or identity.

Students type their answer here.

2. Send and receive email

  • SMTP sends outgoing email from a client and transfers email between mail servers.
  • POP3 downloads email to a client, commonly for local storage; messages may be removed from the server depending on settings.
  • IMAP keeps messages on the server and synchronises mailboxes and changes across devices.

The POP3/IMAP comparison is often assessed through a user with one device versus several devices.

Fill in the blanks3 marks
Outgoing mail uses gap 1. A mailbox synchronised across several devices uses gap 2. Downloading messages for mainly local use can use gap 3.
  • IMAP
  • POP3
  • SMTP
  • Wi-Fi
Written answer3 marks

Compare POP3 with IMAP for a user who reads email on a phone and laptop.

Describe where messages remain and how devices see changes.

Students type their answer here.

3. Carry data on the local link

Ethernet defines rules for data transmission over a wired local network link. Wi-Fi defines rules for wireless local network communication. They belong at the link layer. A laptop may use Wi-Fi to its access point while later links use Ethernet or fibre-related technologies; the upper-layer service can remain the same.

Multiple choice1 mark

At which layer do Ethernet and Wi-Fi operate in the four-layer model?

  • Aapplication
  • Btransport
  • Cinternet
  • Dlink
Written answer2 marks

Explain how a Wi-Fi laptop can communicate with a server reached through wired network links.

Use layering and agreed protocols.

Students type their answer here.

4. Select from the task

Use this examination pattern: task → protocol → purpose. Example: a mail app sends a new message → SMTP → rules for sending/relaying outgoing email. Do not answer FTP merely because an email has an attachment; the dominant task is still email sending.

Written answer3 marks

Name the most suitable protocol for each task and state its purpose: (a) upload a website file to a server; (b) synchronise an inbox across devices; (c) send an email.

Give one protocol-purpose pair for each.

Students type their answer here.

Multiple choice1 mark

Which statement is accurate?

  • AHTTPS guarantees downloaded files contain no malware.
  • BSMTP is used to send email.
  • CIMAP is a wired-link protocol.
  • DEthernet retrieves web pages at the application layer.
Written answer2 marks

Explain why two communicating devices need agreed protocols even if their hardware and operating systems differ.

Connect rules to formatting and interpretation.

Students type their answer here.

Route forward

You can map every required named protocol to its layer and purpose. The checkpoint now combines embedded systems, IoT, packet switching and TCP/IP without introducing new content.