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Computer Networks · Class 12 · Network Protocols
networksprotocols⏱️ 8 min read

Which Protocol, When?

Nine protocols, nine jobs. In the exam you will be asked for a full form, for what one is used for, for the difference between two of them, or — in the case study — which one a company needs. This page puts them side by side.

1All nine on one picture

Nine protocols, one computer

Pick a protocol to see what it talks to. Drag sideways to turn.

HTTPHyperText Transfer Protocol: fetches web pages.

2Full forms and jobs

ProtocolFull formUsed for
📦 TCP/IPTransmission Control Protocol / Internet ProtocolCuts data into packets, addresses and delivers them
↔️ PPPPoint to Point ProtocolA direct link between two devices
🌐 HTTPHyperText Transfer ProtocolFetches web pages
🔒 HTTPSHyperText Transfer Protocol SecureFetches web pages, encrypted
📁 FTPFile Transfer ProtocolTransfers files
📤 SMTPSimple Mail Transfer ProtocolSends email
📥 POP3Post Office Protocol version 3Retrieves email from the mail server
📞 VoIPVoice over Internet ProtocolVoice and video calls over the Internet
⌨️ TELNETTeletype NetworkLogs in to a remote computer
Remember the letters
The T in HTTP, FTP and SMTP is Transfer — each one moves something: hypertext, files, mail. The S at the end of HTTPS is Secure. POP3 is a post office you collect mail from.

3The pairs CBSE asks about

PairThe difference in one lineAsked in
HTTP vs HTTPSHTTPS encrypts the data (SSL/TLS); HTTP sends it as plain textSQP 2023-24; compartment 2025
HTTP vs FTPHTTP fetches web pages to view; FTP transfers files between computersCompartment 2024
FTP vs SMTPFTP transfers files; SMTP sends emailCompartment 2026
SMTP vs POP3SMTP sends mail towards the receiver; POP3 retrieves it from the mail serverEach asked on its own: SMTP SQP 2024-25, POP3 SQP 2025-26
TCP vs IPTCP splits into packets and reassembles them in order; IP addresses and routes each packetBoard 2023; compartment 2025 (full forms)

4Reading a case study

The last part of the 5-mark network question often names a need and asks for a protocol. Look for these words:

If the question says…AnswerSet in
video conferencing / online audio-visual sessions / live interactionVoIPSQP 2022-23; board 2022, 2026; compartment 2022, 2026
voice communication / phone calls over the InternetVoIPBoard 2025; compartment 2024
remote login / remotely access a computerTELNETBoard 2025; compartment 2023
transfer files between branchesFTPBoard 2023; SQP 2024-25
retrieving emails from a mail serverPOP3SQP 2025-26
sending emailsSMTPSQP 2024-25; board 2024
accessing a web pageHTTPCompartment 2026; board 2026
secure browsing / encrypted web pagesHTTPSSQP 2023-24; compartment 2025
Video conferencing is VoIP
CBSE’s own marking scheme answers “a protocol to provide a video conferencing solution” with VoIP. Do not write HTTP just because the meeting happens in a browser.
Which protocol?

Read the situation and pick the protocol.

1 of 12score 0
The Delhi and Mumbai offices hold a video conference every Monday

Every question CBSE has set on protocols is collected, with answers, on the next page: Board Questions.

5Check yourself

Quick Check

Which protocol carries the data of all the others across the Internet?

Quick Check

A company wants its managers in Delhi and Ambala to talk live over the Internet. Which protocol should be suggested?