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Bennett University

• Course: Computer Networks (CSET207)

• Instructor: Dr. Ashish Tomar

• Role: Assistant Professor

Introduction to Computer Networks

• Overview of the importance and functionality of computer networks.

Outline of Topics

• Why Computer Networks?

• Computer Network Basics

• Applications of Computer Networks

• Transmission Media

Course Structure

Module 1 (9 hours)

• Key Topics:

  • Applications of Networks

  • Transmission Media

  • Connecting Devices

• Local Area Networks (LAN) Topologies:

  • Bus

  • Ring

  • Star

  • Mesh

  • Hybrid

• The OSI Reference Model

• TCP/IP Protocol Suite

• Physical Layer:

  • Services, Line coding scheme, Modulation, Multiplexing, Switching methods, Ethernet, Bluetooth, Wi-Fi, Wi-Fi Direct, WPA/WPA2/WPA3

• Data Link Layer:

  • Services, Framing, Switches

Module 2 (8 hours)

• Reliable Data Delivery:

  • Error detection, Correction, Flow control (Stop and wait, Go Back-N, S-R Protocol)

  • Retransmission Techniques, Timers

• Medium Access Sublayer:

  • Channel Allocations (ALOHA protocols, CSMA, CSMA/CD)

• Network Layer Protocols:

  • Services (IP, ICMP), IP Addressing, Subnetting, Supernetting (CIDR, IPV4, IPV6)

Module 3 (9 hours)

• Routing and Forwarding

  • Static and dynamic routing; Unicast and Multicast Routing

  • Distance-Vector and Link-State Routing

  • Shortest Path Computation (Dijkstra's Algorithm)

  • Address Mapping (ARP, RARP, BOOTP, DHCP)

• Transport Layer Services:

  • UDP, TCP segment formats, Connection establishment and termination

  • Congestion Control (Open Loop, Closed Loop)

Module 4 (7 hours)

• Session Layer, Presentation Layer, Application Layer Services:

  • DNS, SIP, RTP, Telnet/SSH, HTTP, HTTPS, Email (SMTP), FTP Commands and Replies, WWW, SNMP

• Addressing Schemes

Module 5 (9 hours)

• Cryptography Principles: Symmetric Key, Public Key

• Authentication Protocols: Digital Signatures

• Layer Security: Secure Email, SSL, IP Security

• Advanced Topics: Dark Net, Content-Aware Search Systems, Software-Defined Networking, Cloud Systems, Data Centers, 4G & 5G Networks, Body Area Sensor Networks, Satellite Networks, SWARM Networks

Computer Network Basics

• Definition: A network comprises a set of devices (nodes) linked by communication channels.

• Nodes: Devices that send and receive data (e.g., computers, printers).

• Communication Channels: Links connecting devices, allowing data sharing; e.g., Internet as a primary example.

Why Computer Networks?

• File/Application Sharing: Facilitates data transfer and resource access.

• Hardware Sharing: Enables sharing of devices (e.g., printers).

• Client-Server Model: Centralizes data storage on servers for client access.

• Voice over IP (VoIP): Allows voice data transmission over Internet Protocols.

• Storage Solutions: Access data remotely or from other devices.

Applications of Computer Networks

Marketing and Sales

• Collect, exchange, and analyze customer data.

Manufacturing

• Enables collaborative work via Computer-Assisted Manufacturing (CAM) and Designing (CAD).

Financial Services

• Facilitates services like Electronic Funds Transfer (EFT), credit history checks, and investments.

Teleconferencing

• Supports conferencing without physical presence; includes text, voice, and video conferencing.

Cable Television

• Enables services like video on demand (VOD).

Electronic Messaging

• E-mail: For communication.

Electronic Data Interchange (EDI)

• Transfers business data electronically, reducing paperwork.

Directory Services

• Centralized file storage for efficient worldwide searches.

Cellular Telephony

• Maintains wireless communications over distances via cellular networks.

Data Communication

• Definition: Exchange of data between devices through transmission media.

• Types:

  • Local Communication: Occurs within the same area/building.

  • Remote Communication: Takes place over distances.

• Effectiveness Criteria:

  • Delivery: Must reach the correct destination.

  • Timeliness: Must occur promptly.

  • Accuracy: Data must be correct.

Data Communication Components

• Message: Information to deliver.

• Sender: The originator of the message.

• Receiver: The intended recipient of the message.

• Medium: The channel for message transmission.

• Protocol: Rules governing data communication.

Connection Types

• Definition: Networks involve links between devices.

• Types of Connections:

  • Point-to-Point: Direct connection between two devices.

  • Multipoint: Shared connection among multiple devices.

Connection Types: Point to Point

• Examples: Computer connected via telephone line, connection between remote control and TV.

Connection Types: Multipoint

• Definition: Space/time shared among multiple devices.

Transmission Modes

• Definition: Mechanism of data transfer between devices; directs information flow.

• Types:

  • Simplex Mode: One-way data flow.

  • Half Duplex Mode: Two-way, but not simultaneously.

  • Full Duplex Mode: Two-way simultaneous data flow.

Transmission Media

• Definition: Channels carrying information from source to destination.

• Examples: Free space, metallic cable, fiber-optic cable.

• Signal Transmission: Uses electromagnetic energy through media.

Transmission Media Types

• Guided Media: Signals directed and contained by physical medium.

• Unguided Media: Use of electromagnetic waves without physical conductors;

  • Examples: Coaxial, Fiber Optics, Twisted Pair, etc.

Guided Media: Twisted Pair Cable

• Structure: Pair of cables twisted together.

• Use: For voice and data channels; economical and lightweight.

Guided Media: UTP vs STP

• UTP: Less interference, commonly used (Cat-5, Cat-6) with RJ45 connectors.

• STP: Has shielding against interference; bulkier and more expensive.

Guided Media: Coaxial

• Structure: Two parallel conductors; shielded and provides better insulation.

• Uses: Cable TV, Ethernet.

Guided Media: Fiber Optic

• Structure: Made of glass or plastic; uses light to transmit data.

• Advantages: High speed, long-distance capability; but expensive and difficult to maintain.

Unguided Media: Wireless

• Definition: Transmits signals without conductors, broadcasted through free space.