Basics of Flow Control in Data Link Layer
Duration: 7 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- About the Course: About the Course
- Section 1 | Language (Hindi): भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material), वर्णमाला
- Section 1 | Language (उर्दू भाषा — 22 प्रश्न (निश्चित)): Spelling & Diacritics, Grammar (اسم, فعل, صفت, ضمیر), Vocabulary, Idioms & Proverbs, Comprehension
- Section 1 | Language (বাংলা / बांग्ला भाषा — 22 प्रश्न (निश्चित)): Bangla Script and Sounds, Bangla Grammar and Usage, Bangla Word Formation and Vocabulary, Reading and Text Interpretation
- Section 1 | Language (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Pronoun, Verb, Adverb, Preposition, Articles, Determiner, Conjunction, Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Construction, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Facts, Inference and Judgements
- Section 2 | Primary Maths & Reasoning: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Percentage, Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Mensuration and Geometry, Age Problems, Arithmetic, Powers and Exponents (Surds and Indices), Algebra, Probability, Trigonometry, Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence
- Section 2 | General Awareness (GK + Current Affairs): Polity, Physics, Biology, State Wise GK, Chemistry, History, Geography, Indian Economy, Environment, GK- Current Affairs, Static General Knowledge
- Section 3 | Computer System and Org. (CSO): Basics of COA, Floating Point Rep, Cache Memory Organization, Instr Formats & Modes, Programming the Basic Computer, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design
- Section 3 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control
- Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
- Section 3 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics
- Section 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Shortest Path Algos
- Section 3 | Theory Of Computation & Compiler Design: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
- Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Artificial Intelligence, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications
- Section 3 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Maintenance and Configuration Management, Software Testing
- Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
- Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
- Section 3 | Java: Java Fundamentals, Array, String, IO & References
- Section 3 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
- Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
- Section 3 | Multimedia: Multimedia
- BPSC Previous Year Papers:
- BPSC Full Mock Tests:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This lecture introduces flow and error control mechanisms within the Data Link Layer of computer networks. The instructor begins by defining flow control as a method to prevent overwhelming the receiver, utilizing memory buffers for temporary data storage. Key concepts include the necessity of checking incoming data before processing and the requirement for receivers to signal senders to halt transmission when buffers fill. The lesson transitions to error control, defined as the detection and retransmission of lost or corrupt frames. The instructor introduces Automatic Repeat Request (ARQ) as the primary implementation method, classifying protocols based on channel types: noiseless channels utilize simple methods like Stop-and-Wait, while noisy channels require complex protocols such as Go-Back-N and Selective Repeat. Visual aids include whiteboard diagrams of devices A and B, buffer filling illustrations with cross-hatching, and hierarchical classifications of ARQ protocols.
Chapters
0:00 – 2:00 00:00-02:00
The instructor introduces flow control concepts using a slide titled "FLOW AND ERROR CONTROL" which lists four numbered points. Point 1 states data flow must not overwhelm the receiver, while Point 2 highlights buffer usage for storing incoming data. The instructor draws a diagram with two boxes labeled "A" and "B" connected by a line to illustrate sender-receiver communication. Text on screen emphasizes that receiving devices have limited processing speeds and memory buffers, requiring them to inform the sender before limits are reached.
2:00 – 5:00 02:00-05:00
The lecture transitions to error control mechanisms, defining it as detection and retransmission of lost or corrupt frames. The instructor uses a whiteboard to draw diagrams connecting devices A and B, illustrating buffering scenarios where cross-hatching demonstrates buffer filling when data arrives faster than processing speed. Visible text outlines that flow control prevents receiver overwhelm by storing data until processed. The lesson introduces Automatic Repeat Request (ARQ) as a simple implementation where damaged frames trigger retransmission, marking the shift from flow management to error handling.
5:00 – 7:18 05:00-07:18
The instructor explains error control protocols, specifically focusing on Automatic Repeat Request (ARQ) classifications. A hierarchical diagram classifies protocols for noiseless versus noisy channels, with the instructor using gestures to distinguish between these types. Specific ARQ protocols listed include Stop-and-Wait for noiseless channels, described as the simplest method, and Go-Back-N and Selective Repeat for noisy environments. Text on screen defines error control as both detection and correction, though the data link layer primarily focuses on retransmission methods.
The lecture systematically progresses from flow control to error control within the Data Link Layer. Flow control is established as a buffer management technique where receivers signal senders to halt transmission when memory limits approach, preventing data loss due to processing speed mismatches. Error control is then introduced as a mechanism for handling lost or corrupt frames through detection and retransmission. The instructor categorizes ARQ protocols into those suitable for noiseless channels, such as Stop-and-Wait, and those designed for noisy environments like Go-Back-N and Selective Repeat. This progression highlights the layered approach to ensuring reliable data transmission, starting with rate matching and advancing to integrity verification.