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Computer Networks · Class 12 · Network Protocols · Carrying Data
networksprotocols⏱️ 5 min read

PPP

🎬 This chapter has a 10:53 video: Network Protocols →

Some links have exactly two devices on them, one at each end — a cable straight from one router to another. Before they trust each other with data, the two should check who is on the other end. PPP is the protocol for that kind of link.

1What PPP is

PPP
PPP stands for Point to Point Protocol. It sets up a dedicated, direct connection between two communicating devices. It decides how the two devices authenticate (check) each other and set up the direct link to exchange data.

Point to point means one device at each end of the link and nobody else on it. Authenticate means prove who you are — usually with a user name and password.

Check first, then connect

Play with the right password, then with a wrong one. Drag sideways to turn.

Press ▶ Play to connect the school's router to the ISP's router with PPP.

2Where PPP is used

  • Two routers joined directly by a line talk to each other using PPP.
  • A home computer connecting to its Internet Service Provider (ISP) through a modem uses PPP. Many broadband connections still log in this way.

Both devices must be able to send and receive at the same time (full duplex), because data flows both ways over the link at once.

Think of a guard at a gate

A car drives up to a gate with one guard. The driver shows a pass. Only when the guard is satisfied does the gate open — and then the road beyond joins just those two places.
About NCERT's last line on PPP
NCERT also says PPP makes sure packets arrive in order and asks the sender to resend damaged or lost ones. Strictly, PPP checks each piece of data for damage and throws damaged ones away; asking for them again and putting packets in order is usually TCP’s work. Writing NCERT’s line in the exam is fine.

3From the board papers

1
Expand the term PPP. What is the use of PPP?CBSE board exam 2025 · the full form alone in sample paper 2022-23 and board exams 2022, 2024
2 marks
▶Show the answer

Point to Point Protocol. It is used to set up a direct, dedicated connection between two devices — for example two routers, or a home computer and its ISP — after the two authenticate each other.

4Check yourself

Quick Check

How many devices does a PPP link connect?

Quick Check

What do two devices do with PPP before they exchange data?

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