Oxford Cambridge and RSA
GCSE (9-1) Computer Science
Computer Systems
J277/01
Topic: Unit 1.3 Network Protocols & Layers
Time allowed: 30 minutes
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INSTRUCTIONS
Use black ink.
Answer all the questions.
INFORMATION
The total mark for this paper is 20.
The marks for each question are shown in brackets [ ].
Turn over
1
Draw a line to match each protocol acronym to its correct full name.
[4]
Acronym
HTTP
FTP
SMTP
IMAP
Full Name
Simple Mail Transfer Protocol
Internet Message Access Protocol
Hypertext Transfer Protocol
File Transfer Protocol
2
Scenario:
A student, Leo, is setting up an email app on his smartphone and his laptop. He wants to be able to read his emails on both devices. If he deletes an email on his phone, he wants it to also be deleted on his laptop.
(a) Identify the most suitable email retrieval protocol for Leo to use.
[1]
(b) Explain why the protocol you chose in part (a) is better for Leo than POP (Post Office Protocol).
[2]
(c) Leo writes a new email and presses "Send".
State the name of the protocol used to send the email from Leo's device to the email server.
[1]
Turn over
3
A web developer is creating a website for an online bank where users can log in to view their savings.
(a) The developer needs to upload the website files (HTML and images) from their local computer to the web server.
Identify the standard protocol used for this task.
[1]
(b) The bank website currently uses HTTP. The developer insists they must upgrade to HTTPS.
Explain the difference between HTTP and HTTPS and why HTTPS is essential for an online bank.
[3]
4
The Internet operates using the TCP/IP model.
(a) Explain the role of TCP (Transmission Control Protocol) when sending data.
[2]
(b) Explain the role of IP (Internet Protocol) when sending data.
[2]
[Image of tcp ip model layers diagram]
(c) Network protocols are divided into layers (e.g., Application, Transport, Internet, Link).
Explain two benefits of using layers.
[4]
Benefit 1:
Benefit 2:
5
Extended Short Answer:
A user types a URL into a web browser.
Describe the relationship between the web browser, the web server, and the protocol HTTP during this process.