Topic_1_-_Introduction_to_Networking_v4

Topic 1: Introduction to Networking

1. Introduction to Networks

  • Overview of networking concepts (not detailed in the transcript)

2. Objectives

  • Topic Objective: Explain the advances in modern technologies.

  • Network Components:

    • Explain how host and network devices are used.

  • Network Representations and Topologies:

    • Explain network representations and their use in network topologies.

  • Common Types of Networks:

    • Compare characteristics of common networks.

  • Internet Connections:

    • Explain how LANs and WANs interconnect to the internet.

  • Reliable Networks:

    • Describe the four basic requirements of a reliable network.

3. Network Components

3.1 Host Roles

  • Client-Server Model:

    • A host or end device is any computer on a network.

    • Servers:

      • Provide information to clients (e.g., email servers, web servers, file servers).

    • Clients:

      • Send requests to servers for information (e.g., accessing web pages, emails).

3.2 Server Types

  • Email Server:

    • Runs email server software; accessed by client software.

  • Web Server:

    • Runs web server software; accessed via browsers.

  • File Server:

    • Stores files; accessed by client devices.

3.3 Peer-to-Peer Networks

  • Functionality:

    • Devices can be both clients and servers.

  • Advantages:

    • Easy to set up, less complex, lower cost.

  • Disadvantages:

    • No centralized administration, less secure, not scalable, slower performance.

3.4 Key Components

  • Intermediary Devices:

    • Connect end devices and networks; determine data flow paths.

  • Media:

    • Data transmission pathways connecting devices.

3.5 Intermediary Network Devices

  • Connect end devices and multiple networks.

  • Determine message paths using destination addresses and network interconnection information.

3.6 Network Media

  • Types:

    • Metal Wires:

      • Data in electrical impulses.

    • Fiber-Optic Cables:

      • Data in light pulses.

    • Wireless Transmission:

      • Data using electromagnetic waves.

  • Selection Criteria:

    • Maximum distance, installation environment, data amount & speed, cost.

4. Network Representations and Topologies

4.1 Network Representations

  • Use diagrams (topology diagrams) to represent network devices.

  • Important terms: NIC, physical port, interface.

4.2 Topology Diagrams

  • Physical Topology:

    • Illustrates physical locations and cable installations.

  • Logical Topology:

    • Illustrates devices, ports, media, and addressing schemes.

5. Common Types of Networks

5.1 Categories by Size

  • Small Home Networks:

    • Connect a few computers and the Internet.

  • Small Office/Home Office:

    • Connect computers to a corporate network.

  • Medium to Large Networks:

    • Many locations, thousands of interconnected computers.

  • World Wide Networks:

    • Connect millions of computers globally.

5.2 LANs and WANs

  • Variability in Infrastructure:

    • Coverage area, user count, service types, administrative area.

  • Definitions:

    • LAN:

      • Spans a small geographical area.

    • WAN:

      • Spans a wide geographical area.

5.3 Characteristics of LANs vs. WANs

  • LAN:

    • Limited area, administered by a single entity, high-speed bandwidth.

  • WAN:

    • Covers wide areas, administered by service providers, typically slower speed links.

5.4 The Internet

  • A collection of interconnected LANs and WANs.

  • Not owned by any individual; maintained by groups like IETF, ICANN, and IAB.

5.5 Intranets and Extranets

  • Intranet:

    • Private LAN/WAN for authorized organizational members.

  • Extranet:

    • Provides secure access for individuals from other organizations.

6. Internet Connections

6.1 Home and Office Connections

  • Types:

    • FTTP/FTTH:

      • High bandwidth fiber connection, always on.

    • Cable:

      • High bandwidth from cable providers.

    • DSL:

      • High bandwidth over telephone lines.

    • Cellular:

      • Internet through cell networks.

    • Satellite:

      • Beneficial for rural users.

    • Dial-Up:

      • Inexpensive, low bandwidth option.

6.2 Business Connections

  • Require higher bandwidth, dedicated connections.

  • Offered by service providers via leased lines, business DSL, and Metro Ethernet.

7. Reliable Networks

7.1 Network Architecture

  • Supports data movement across networks.

  • Must address:

    • Fault tolerance, scalability, quality of service (QoS), security.

7.2 Fault Tolerance

  • Limits failure impact, provides redundancy, uses packet switched networks for flexibility.

7.3 Scalability

  • Allows quick expansion to support new users without degrading performance.

  • Achieved with modular network devices and adherence to protocols.

7.4 Quality of Service

  • Ensures high service quality for voice and video; manages network congestion using QoS policies.

7.5 Network Security

  • Types:

    • Infrastructure security and data security.

  • Focus on maintaining confidentiality, integrity, and availability of data.