GATE CSE · Computer Networks

Data Link Layer Notes & Formulas

Generate GATE-level questions covering framing, error detection (CRC, checksum), error correction, flow control, and MAC protocols (ALOHA, Slotted ALOHA, CSMA/CD). Include efficiency and probability-based problems.

Concept summary for GATE CSE 2027 · 150 practice questions available

📘 Data Link Layer – Concept Summary

1. Definition

Responsible for node-to-node delivery and error detection.

2. Core Idea

Ensures reliable transmission over physical link.

3. Framing

Divides data into frames
Methods:
- Byte stuffing
- Bit stuffing

4. Error Detection

Parity Bit
CRC (Very Important)
Checksum

5. Error Control

ARQ protocols:
- Stop-and-Wait ARQ
- Go-Back-N
- Selective Repeat

6. MAC Protocols

CSMA/CD (Ethernet)
CSMA/CA (WiFi)

7. GATE Trick

If CRC, framing, ARQ → Data Link Layer

Practice 150 Data Link Layer questions →