CSMA-CD Part - 2
Duration: 5 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- Quantitative Ability: Percentage, Profit and Loss, Ratio and Proportion (Ratios), Average, Time and Work, Speed Time and Distance, Simple Interest and Compound Interest, Age Problems, Number System, Divisibility Rules, HCF LCM, Algebra, Permutation and Combination, Probability, Data Interpretation, Logarithm, Sequence and Series (Series), Powers and Exponents (Surds and Indices), Speed Mathematics and Basic Mathematics
- Logical Reasoning: Seating Arrangements, Puzzle Solving (Puzzles), Data Arrangement, Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Data Sufficiency, Venn Diagram, Inequality, Series (Number and Letter Series) (Numerical Relations and Reasoning), Logical Sequence Of Words, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning)
- Verbal Ability: Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Subject Verb Agreement (Verb Noun Agreement), Tenses, Articles, Preposition, Conjunction, Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Vocabulary, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Completion (Fill in the blanks), Sentence Correction (Error Correction), Cloze Test (Cloze Passage), Facts, Inference and Judgements
- Programming Fundamentals (Technical): C Fundamentals
- Data Structures (Technical): Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
- Algorithms (Technical): Algorithm Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Time Complexity Analysis, Advanced Algorithms
- OOPs (Technical): Object Oriented Programming (OOPS)
- DBMS (Technical): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
- SQL (Technical): SQL
- Operating Systems (Technical): Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
- Computer Networks (Technical): Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Cloud Computing and IoT, Cyber and Info Security
- Software Engineering (Technical): Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
- Coding/Automata Round: Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Java, Python for Placements by Yash Sir, Pseudo Codes
- Personality / Behavioral Assessment: Behavioral Assessment (Behavioral Competency Profiling) (Psychometric Test)
- Writing Assessment: English Writing Ability
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This lecture segment introduces the CSMA-CD protocol flowchart, defining key variables such as $K$ (Number of attempts) and $T_p$ (Maximum propagation time). The instructor explains the process starting with applying persistence methods like 1-persistent, nonpersistent, or p-persistent. Upon transmission, the system checks for collisions; if detected, it sends a jamming signal and increments $K$. The back-off procedure involves calculating a random number $R$ between 0 and $2^K - 1$, then waiting for time $T_B = R \times T_p$. The total transmission time is noted as $T_T = 2 \times T_p$.
Chapters
0:00 – 2:00 00:00-02:00
The lecture begins with a flowchart displayed on screen, defining variables $K$ and $T_p$. The instructor points to the step "Apply one of the persistence methods (1-persistent, nonpersistent, or p persistent)". A handwritten formula $T_T = 2 \times T_p$ appears in the top right corner. The flowchart illustrates the initial transmission phase and collision detection logic, with decision diamonds checking if "(Transmission done) or (Collision detected)."
2:00 – 4:58 02:00-04:58
The instructor details the collision handling mechanism, specifically pointing to a circled box labeled "Send a jamming signal". He explains the back-off procedure where $T_B = R \times T_p$ or $R \times T_{fr}$ is calculated. The flowchart shows the loop where $K$ increments after a collision, and a random number $R$ is chosen between 0 and $2^K - 1$. The diagram concludes with the "Wait TBtime" step before retrying transmission.
The video provides a structured walkthrough of the CSMA-CD protocol using a visual flowchart. Key concepts include persistence methods for channel access, collision detection via jamming signals, and the exponential back-off algorithm. The instructor emphasizes the mathematical relationships between propagation time ($T_p$), transmission attempts ($K$), and back-off duration ($T_B$). The formula $T_T = 2 \times T_p$ represents the round-trip propagation time, critical for collision detection windows. The back-off mechanism ensures network stability by randomizing retransmission times based on the number of previous collisions.

