CN (Computer Networks) Notes

on
https://drive.google.com/file/d/10GeeElfW-OMRiU_ay9J32XzcZaYCKeoM/view?usp=sharing



These documents explore the foundational concepts covered in Computer Networks and are organised into four main units. Here is an explanation of the topics with a one-line description for each:  https://drive.google.com/file/d/1z4F7TUkEFpB2uqxCmSGUmEc1zl7pipqp/view?usp=sharing




Unit I: Introduction and Physical Layer

  • Computer Networks: A collection of autonomous computers connected via various media to share resources and information.
  • Network Topology: The geometric arrangement of links and nodes in a network, such as Mesh, Star, Bus, and Ring.
  • Network Categories: The classification of networks based on size and geographical coverage, primarily LAN (Local), MAN (Metropolitan), and WAN (Wide).
  • OSI Reference Model: A seven-layer architectural model that standardizes network communication functions.
  • TCP/IP Reference Model: A four-layer protocol suite (Application, Transport, Internet, Link) used as the foundation for the Internet.
  • Transmission Media: The physical paths used to carry information, categorized into guided (wired like twisted pair, fiber) and unguided (wireless like radio waves).
       https://drive.google.com/file/d/1hFBquwNmpIOs6WJ_aIylMDmS-z7QqxR5/view?usp=sharing



Unit II: Data Link Layer and Media Access Control

  • Data Link Layer Design Issues: Focuses on providing a well-defined service interface to the network layer, grouping bits into frames, and handling transmission errors.
  • Framing: The process of breaking up the raw bit stream into discrete frames using methods like character counts or bit stuffing.
  • Error Control: Mechanisms using redundancy (like Parity, Checksum, and CRC) to detect and correct errors caused by noise.
  • Flow Control: Techniques such as Stop-and-Wait ensuring a fast sender does not overwhelm a slow receiver.
  • Sliding Window Protocols: Protocols like Go-Back-N and Selective Repeat that allow multiple frames to be in transit simultaneously to improve efficiency.
  • Channel Allocation: Methods for dividing a single channel among multiple users, either statically (FDM) or dynamically.
  • Random Access Protocols: Protocols like ALOHA and CSMA where stations compete for the channel, potentially leading to collisions.
  • Collision-Free Protocols: Techniques like Bit-map and Binary Countdown that ensure no two stations transmit simultaneously.
  • Wireless LANs (IEEE 802.11): Wireless standards using CSMA/CA (Collision Avoidance) rather than Collision Detection to manage shared radio frequencies.
  • Switching and Bridging: Devices used to connect different LAN segments and filter traffic based on MAC addresses.
  https://drive.google.com/file/d/1Fg9moSkgxNXDZpzRWq350ll8n1r69abc/view?usp=sharing https://drive.google.com/file/d/1fjowHE3kY9nKsmi7ZMIVo8eRtaMt9N5Z/view?usp=sharing https://drive.google.com/file/d/1uk1rrsaXMaVrmrB4DajFlXJZRCnH1rIG/view?usp=sharing




Unit III: Network Layer

  • Store-and-Forward Switching: A technique where a packet is fully received and verified by a router before being forwarded to the next link.
  • Connectionless vs. Connection-Oriented: The choice between sending independent datagrams or establishing a virtual circuit path before transmission.
  • Routing Algorithms: Logic used to determine the best path for a packet, including Shortest Path (Dijkstra's) and Distance Vector Routing.
  • Hierarchical Routing: A strategy to reduce routing table sizes by dividing routers into regions and clusters.
  • Congestion Control: Algorithms like Leaky Bucket and Token Bucket used to prevent or remove excessive load in the network.
  • Quality of Service (QoS): Parameters such as reliability, delay, jitter, and bandwidth that determine the performance level of a network service.
  • Internetworking Devices: Hardware like Repeaters, Hubs, Bridges, Switches, Routers, and Gateways used to connect different networks.
  • IP Protocol: The unreliable, connectionless protocol responsible for addressing and routing packets across the Internet.
  • ARP and RARP: Protocols used to map IP addresses to physical MAC addresses and vice versa.
  • Subnetting: The process of dividing a large network into smaller, manageable sub-networks using subnet masks.
  https://drive.google.com/file/d/1k65bAvvbxq8evITWSfJSeS4wFN0Ogjmi/view?usp=sharing



Unit IV: Application Layer

  • Application Layer: The topmost layer that provides interfaces and services directly to user applications like email and file transfer.
  • Domain Name System (DNS): A directory service that maps human-readable hostnames to numerical IP addresses.
  • SNMP (Simple Network Management Protocol): A framework containing Managers and Agents used for monitoring and controlling network devices.
  • Electronic Mail: A system comprising User Agents and Message Transfer Agents (like SMTP) for sending and receiving digital messages.
  • World Wide Web (WWW): A distributed client/server service consisting of electronic documents linked via Hypertext.
  • HTTP (HyperText Transfer Protocol): A stateless protocol used to fetch and transfer web documents between clients and servers.
  • Content Delivery Network (CDN): A network of geographically distributed servers designed to deliver web content to users faster.

Comments

Post a Comment