Chapter 9: Networks and Network Devices

Chapter 9: Networks and Network Devices

Course Information

Course Title: Computer Literacy - CIT 100
Semester: Spring 2026
Class Schedule: Tuesday & Thursday, 2:00 PM - 3:15 PM
Location: Middletown BT 113
Instructor: Mike Benson

Module Objectives

By the end of this module, students should be able to:

  • Explain how a user interacts with a network.

  • Identify types of network structures.

  • Describe network standards and protocols.

  • Explain how to use hardware to connect to a network.

  • Explain how to set up a network.

  • Identify network security tools.

  • Describe the role of a network professional.

How Do You Interact with a Network?

  • A network is a system comprising two or more devices linked by wires, cables, or a telecommunications system.

  • Networks allow resource sharing among computers, including hardware, software, data, and information.

  • The operation of a network requires a combination of hardware and software.

  • Networks can provide connections to the Internet, necessitating the services of an Internet Service Provider (ISP).

Networks as Communications Systems

  • Modern devices, including even the smallest computers, can communicate directly with each other, corporate networks, or millions of computers globally—often via the Internet.

  • The process of data, instructions, and information transfer between devices is known as digital communications.

  • All types of computers and mobile devices can serve as both sending and receiving devices in communications systems.

Communications Devices

  • Communications device: Connects the sending device to the transmission media.

  • Receiving device: Accepts data, instructions, or information transmissions.

  • Sending device: Initiates instructions to transmit data, instructions, or information.

  • Transmission media: The means by which data, instructions, or information travel.

Types of Network Structures

1. Home Networks

  • Exist within a single building.

  • Easy to install and configure.

  • Accessed by a limited number of users.

  • Advantages include:

    • Sharing a single Internet connection among multiple users.

    • Sharing files across computers (e.g., photos).

    • Sharing hardware resources like printers.

    • Enabling online gaming through game consoles.

    • Supporting Voice over IP (VoIP) services for voice communication.

    • Connecting smart devices (thermostats, light switches, etc.) to the Internet.

2. Business Networks

  • Accommodate many users and pass large amounts of data.

  • May stretch across multiple buildings.

  • Advantages include:

    • Facilitating employee communication.

    • Sharing hardware (printers/scanners) and data.

    • Centrally storing and backing up critical information.

3. Intranet vs. Extranet

  • Intranet: An internal network using Internet technologies.

  • Extranet: Allows external customers or suppliers access to parts of the intranet.

  • VPN (Virtual Private Network): Enables individual secure access to an organization's network, protecting transmitted data using encryption and other technologies.

Network Types by Connection

Wired Networks

  • Transmits signals and data through cables (Ethernet, USB, etc.) traveling through floors and walls.

  • Tends to be more secure and faster than wireless networks.

Wireless Networks

  • Transmits signals through airwaves, usually without requiring cables.

  • Can be less secure than wired networks but are easier to set up and more convenient.

Cellular Networks

  • Utilizes mobile phones for both voice calls and Internet access.

  • Types include 3G, 4G, and 5G, with 5G offering high-speed data transmission.

GPS (Global Positioning System)

  • A navigation system using earth-based receivers to analyze satellite signals to determine geographic location.

  • Applications include mapping, route optimization, locating lost objects, and monitoring movements.

Communications Software

  • Consists of programs and applications that:

    • Establish connections between computers or devices.

    • Manage data transmission.

    • Provide user interfaces for communication (e.g., email, chat, VoIP).

Network Structures

  • Topology: The physical arrangement of devices on a network.

  • Network Architecture: The logical configuration of devices and resources.

  • Geographic Span: The reach of a network, categorized by its size and usage (private or public).

  • Types of network topologies include:

    • Bus Network: Devices connected to a central cable (bus).

    • If the bus fails, communication ceases.

    • Mesh Network: All devices interconnected; if one fails, others communicate via alternative paths.

    • Types: Full mesh (each device connects to every other) and partial mesh (not all devices connect to each other).

    • Ring Network: Data travels sequentially from device to device.

    • If one device fails, communication ceases.

    • Star Network: Devices connect to a central hub (server, switch).

    • If the central hub fails, communication fails between connected devices but not if a peripheral device fails.

Network Architecture

Client/Server Network

  • Comprises servers and client devices.

  • Servers provide resources, while clients request them.

  • Controlled by a network administrator.

Peer-to-Peer (P2P) Network

  • Connects a small number of computers directly to each other without a centralized server.

  • Users share resources directly with one another.

  • Internet P2P networking involves sharing files directly over the Internet; legality varies with copyright status.

Geographic Reach Definitions

  • Local Area Network (LAN): Connects computers in a limited area.

  • Wireless LAN (WLAN): A LAN using wireless technology.

  • Wide Area Network (WAN): Covers a large geographic area.

  • Metropolitan Area Network (MAN): Operated by a city/county.

  • Personal Area Network (PAN): Connects personal digital devices (e.g., via Bluetooth) within about 30 feet.

  • Body Area Network (BAN): Subset of PAN; consists of miniature biosensors implanted in the body.

Network Standards and Protocols

Network Standards

  • Define usage guidelines for hardware access, data transmission speeds, types of connections, and media.

  • Ensure compatibility between devices (e.g., Ethernet for wired networks).

  • Protocols outline communication standards (data format, error handling).

Common Standards and Protocols

  • Bluetooth: Wireless protocol for short-range communication (up to 3 Mbps).

  • IrDA (Infrared Data Association): Data transfer using infrared light; requires line-of-sight.

  • LTE (Long-Term Evolution): Standard for mobile phones.

  • NFC (Near-Field Communication): Used for close-range communication with credit cards or smartphones.

  • RFID (Radio-Frequency Identification): Communicates via radio waves to read tags attached to objects or persons.

  • UWB (Ultra-Wideband): High-speed communication protocol; suitable for large file transmission.

Network Connection Hardware

Nodes and Central Devices

  • Nodes: Devices on a network (e.g., computers, printers).

  • Hub: Central point for connection but transfers data without discretion.

  • Switch: Centralizes connections and routes data to intended recipients only.

  • Router: Connects multiple networks and directs data flow.

  • Modem: Connects devices to communication channels (e.g., Internet).

Modem Types

  • Cable Modem: Connects via cable TV lines.

  • DSL Modem: Uses standard copper telephone lines.

  • ISDN Modem: Broadband modem managing digital communications through ISDN lines.

Setting Up a Network

  1. Basic Setup: Connect devices using cables for a simple network.

  2. Wireless Setup: Requires modem, router, and access point.

  3. Steps:

    • Purchase and connect modem/router.

    • Enable wireless features and configure settings (network name, security key).

    • Enable device wireless functionalities and connect.

Securing Your Network

Common Network Risks

  • Adware: Unwanted advertisements.

  • Spyware: Tracks and transmits personal data without user consent.

  • Virus: Damages data/system settings.

  • Worm: Spreads autonomously within networks.

  • Trojan: Masquerades as legitimate software but harms systems once executed.

  • Ransomware: Denies access to data until ransom is paid.

  • Rootkit: Gains unauthorized access at the system level.

Security Best Practices

  • Regularly update network keys and monitor connected devices.

  • Use encryption for data transmission.

  • Implement firewalls to filter traffic and protect internal network integrity.

Responsibilities of a Network Professional

  • Role Overview: Network administrators oversee network planning, design, equipment procurement, setup, security, and maintenance.

  • Ethics and Standards: Guidelines for professionalism, privacy, responsibility, and communication are key components within the ethical frameworks developed by organizations like USENIX.

  • Key Responsibilities: Ensuring system integrity, providing education, and maintaining ethical responsibilities towards both the computing community and laws and policies.