CS602 Computer Networks Unit 2 notes and PYQ analysis for RGPV CSE 6th Semester. This unit covers Data Link Layer, framing, error detection, error correction, flow control, Stop and Wait, Go Back N and Selective Repeat protocols.
Unit 2 focuses on the Data Link Layer. It explains how raw bits are converted into frames, how errors are detected and corrected, and how sender and receiver maintain reliable communication.
Understand functions, responsibilities and importance of the Data Link Layer.
Learn character count, byte stuffing, bit stuffing and flag-based framing methods.
Study parity check, checksum, CRC and Hamming Code for reliable data transfer.
Complete syllabus-based topics of CS602 Computer Networks Unit 2.
Functions, responsibilities and importance of Data Link Layer in network communication.
Character count, byte stuffing, bit stuffing and flag-based framing methods.
Parity check, checksum and CRC methods used for detecting errors in frames.
Hamming code and basic correction techniques for handling corrupted data.
Techniques used to control the speed difference between sender and receiver.
Stop-and-Wait, Sliding Window, Go-Back-N and Selective Repeat protocols.
These questions are useful for 7 marks and 14 marks answers in RGPV exams.
RGPV B.Tech VI Semester Computer Networks previous year question analysis for Unit 2.
| Year | Question | Topic | Importance |
|---|---|---|---|
| June 2025 | What is the advantage of Go-back-N protocol? How is parameter n determined? Explain working of the protocol if errors, lost packet or Acks occur. | Go Back N ARQ | ★★★★★ |
| June 2025 | What do you mean by Error detection? Write the name of methods. Encode 8-bit binary value using even parity Hamming code. | Error Detection / Hamming Code | ★★★★★ |
| Dec 2024 | Explain in detail about error and flow control mechanisms employed at data link layer. | Error Control / Flow Control | ★★★★★ |
| Dec 2024 | Explain the working principle of Go-Back-N and Selective Repeat protocols. | Go Back N / Selective Repeat | ★★★★★ |
| May 2024 | With the help of suitable diagrams explain Stop and Wait, Go Back N and Selective Repeat protocols. | Data Link Protocols | ★★★★★ |
| May 2023 | What is the data link layer and what services does it provide? | Data Link Layer Services | ★★★★ |
| May 2023 | What is the mechanism of sliding window flow control? Explain with an example. | Sliding Window | ★★★★★ |
| May 2022 | Describe the Stop and Wait flow control technique. | Stop and Wait | ★★★★★ |
| May 2022 | Describe the frame relay protocol architecture and explain the functions of each layer. | Frame Relay / Data Link | ★★★ |
| Dec 2020 | Explain Flow control and Error control. | Flow Control / Error Control | ★★★★★ |
| Topic | Asked Times | Years | Priority |
|---|---|---|---|
| Go Back N ARQ | 3 Times | 2024, 2025 | ★★★★★ Extremely Important |
| Selective Repeat ARQ | 2 Times | 2024 | ★★★★★ Extremely Important |
| Stop and Wait Protocol | 2 Times | 2022, 2024 | ★★★★★ Extremely Important |
| Sliding Window Flow Control | 1 Time | 2023 | ★★★★★ Extremely Important |
| Flow Control and Error Control | 3 Times | 2020, 2024 | ★★★★★ Extremely Important |
| Hamming Code | 1 Time | 2025 | ★★★★ Very Important |
| Data Link Layer Services | 1 Time | 2023 | ★★★★ Very Important |
| Framing Methods | Rare | Expected | ★★★ Important |
| Topic | Chance of Appearing |
|---|---|
| Go Back N ARQ | 95% |
| Selective Repeat ARQ | 95% |
| Sliding Window Flow Control | 90% |
| Stop and Wait Protocol | 90% |
| Flow Control | 85% |
| Error Detection | 80% |
| Error Correction / Hamming Code | 75% |
| CRC | 70% |
| Framing | 60% |
Agar time bahut kam hai, to Go Back N, Selective Repeat, Stop and Wait aur Sliding Window strong kar lo. In topics se Unit 2 ka question attempt karne ka chance sabse zyada hai.
Protocols ke diagrams, sender-receiver working, ACK concept, error/lost packet case, Hamming Code numerical aur CRC method sab prepare karo.
a) Explain Sliding Window Flow Control mechanism with suitable example.
b) Explain Go Back N and Selective Repeat ARQ protocols with neat diagram.
a) Explain Error Detection and Error Correction techniques.
b) Explain Hamming Code and CRC with suitable example.
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It covers Data Link Layer, framing, error detection, error correction and flow control protocols.
Go Back N, Selective Repeat, Stop and Wait and Sliding Window are the most important protocols.
Yes, Hamming Code is important for numerical and error correction based questions.