6 Telecommunication and Networking

Chapter 6: Telecommunications and Networking

Learning Objectives

  • Compare and contrast major types of computer networks: LAN, WAN, and enterprise networks.

  • Describe wireline communication media and transmission technologies.

  • Describe methods for accessing the Internet.

  • Explain the impact of various network applications on business and everyday life, including discovery, communication, collaboration, and education.

Networks Overview

  • Computers constantly exchange information, a process facilitated by telecommunication technologies.

  • Data exchanges occur over various distances and network sizes.

  • Metcalfe’s Law illustrates the growing power of a network: Value of a network ∝ n², where n is the number of network members.

Definition of Computer Networks

  • A computer network connects computers and devices via communication media for transmitting data.

  • Bandwidth: The capacity of data transmission, measured in bits per second.

  • Broadband: Transmission capacities between 1 to 20 megabits per second, facilitated by fibre optics.

Types of Computer Networks

  • Personal Area Networks (PANs): Very small networks, typically connecting personal devices.

  • Local Area Networks (LANs): Connect devices in a limited geographical area. Requires network interface cards (NICs) for each device.

  • Metropolitan Area Networks (MANs): Larger than LANs but smaller than WANs.

  • Wide Area Networks (WANs): Cover large geographic areas and connect multiple LANs.

Local Area Networks (LANs)

  • Connect multiple devices in a specific area.

  • Require NICs and typically operate via wired connections (as opposed to WLANs).

  • Frequently include file servers to manage resources.

Wide Area Networks (WANs)

  • Cover extensive geographical areas, often connecting various LANs.

  • Utilize multiple channels (fiber-optic cables, microwaves, satellites) for high capacity.

  • Routers: Devices that manage data traffic between LANs and the Internet.

Network Economics and Growth

  • The exponential increase in the value of a network emphasizes why larger networks offer significant advantages.

  • User accessibility to the Internet is ballooning, supported by decreasing communication costs.

Analog and Digital Signals

  • Analog Signals: Continuous wave signals.

  • Digital Signals: Discrete binary values.

Modems

  • Devices that convert signals between analog and digital forms.

  • Types include:

    • Dial-up Modems: Operate over telephone lines.

    • Cable Modems: Use cable television infrastructure.

    • DSL Modems: Provide high-speed connections over phone lines.

Modem vs. Router

  • Modem: Connects to the Internet, decodes ISP signals, but does not create a local network.

  • Router: Creates local area networks, manages Wi-Fi connections, and shares the Internet connection amongst devices.

Communication Media and Channels

  • Twisted-pair Wire: Lowest bandwidth, inexpensive, widely available but slow and prone to interference.

  • Coaxial Cable: Higher bandwidth, less susceptible to interference, more expensive.

  • Fibre-optic Cable: Very high bandwidth and security but challenging to work with.

Internet Connection Methods

  • Dial-up: Available where broadband is limited.

  • DSL: Access through existing telephone lines.

  • Cable Modem: Access via coaxial cables; performance may degrade during peak usage.

  • Satellite: For areas lacking other connections.

  • Wireless: Convenient access, increasing with WiMAX technology.

  • Fiber-to-the-home: High-speed but costly.

Web and Networking Layers

  • TCP/IP Protocol: Fundamental for delivering data across networks through packet switching.

  • Packets: Data recommendations sent between devices; TCP handles connection and order, while IP ensures packets arrive at the correct address.

Distributed and Client/Server Computing

  • Distributed Computing: Shares processing tasks among multiple devices.

  • Client/Server Model: A structure where servers provide resources to client machines.

  • Peer-to-Peer (P2P): A form of distributed processing where devices share resources directly.

The Internet and World Wide Web

  • The Internet consists of millions of networks worldwide, operating on the backbone of fibre-optic telecommunications.

  • IP Address: Unique identifier for each computer on the Internet.

  • Domain Name System (DNS): Hierarchical naming convention for identifying addresses on the Internet.

Future of the Internet

  • Concerns over potential Internet slowdowns due to increasing usage and the demand for bandwidth-intensive services.

  • New infrastructure investments are critical.

  • Initiatives like CANARIE advance national research and connectivity.

World Wide Web and Discovery Tools

  • The Web enables effective information organization and retrieval.

  • Tools like search engines, portals, and automatic translation augment information discovery.

  • Different portal types serve various audiences (commercial, affinity, and corporate portals).

Network Applications: Communication

  • Communication via technology encompasses devices like e-mail, chat rooms, VoIP, and web-based customer service tools.

  • Unified communications streamline interactions over diverse platforms.

Network Applications: Collaboration

  • Collaboration among teams can be synchronous (live chat) or asynchronous (e-mail).

  • Technologies support virtual and remote teamwork, enhancing productivity.

Network Applications: Education

  • E-Learning: Utilizing the web for education, facilitating remote and online courses.

  • Benefits: Flexibility, reduced costs, and enhanced access to knowledge.

  • Drawbacks: Potential lack of social interaction, need for digital readiness, and assessment challenges.

Virtual Universities

  • Online education options proliferate across traditional institutions, allowing students to learn remotely.