Computer Networks and Telecommunications

Computer Networks and Telecommunications

• Computer Network: Two or more connected computers
• Network Operating System (NOS): Manages network communications and resources
• Server: A computer on a network providing functions for client computers
• Hubs: Simple devices connecting network components, broadcasting data to all devices
• Switches: More intelligent than hubs, filtering and forwarding data to specific destinations
• Routers: Communications processors routing data packets between networks
• Software-Defined Networking (SDN): Centralized control of network functions on separate commodity servers

Key Digital Networking Technologies

• Client/Server Computing: Decentralizes processing power by distributing it to client devices connected to a server
• Packet Switching: Digital messages sliced into packets, sent along different paths, and reassembled at destination
• TCP/IP: Universal standard allowing different network components to communicate
• Protocol: Set of rules governing information transmission in a network
• TCP (Transmission Control Protocol): Manages data movement, connection establishment, and packet sequencing
• IP (Internet Protocol): Handles packet delivery and reassembly

Network Layers

• Application Layer: Allows applications to access other layers and defines application protocols
• Transport Layer: Provides communication and packet services to the Application Layer
• Internet Layer: Addresses, routes, and packages data packets (IP datagrams)
• Network Interface Layer: Places packets on and receives them from a network medium

Communication Networks

• Digital Signal: Binary waveform, communicating information as discrete states (1s and 0s)
• Analog Signal: Continuous waveform, used for voice communication
• Modems: Convert digital to analog signals and vice versa. Types include cable modems, DSL modems, and wireless modems

Types of Networks

• Local Area Network (LAN): Connects devices within a half-mile radius (e.g., small offices)
• Campus Area Network (CAN): Spans up to 1,000 meters (e.g., college campuses)
• Metropolitan Area Network (MAN): Covers a city or metropolitan area
• Wide Area Network (WAN): Span broad geographical distances (e.g., the Internet)

Transmission Media

• Transmission Media: Physical materials for transmitting data (twisted pair wire, coaxial cable, fiber optics, wireless)
• Bandwidth: Range of frequencies on a telecommunications channel
• Transmission Speed: Measured in bits per second (bps)
• Hertz (Hz): Unit of frequency (one cycle per second)

The Global Internet

• Internet: Global communication system
• Internet Service Provider (ISP): Commercial organization with permanent internet connections
• Broadband Connections: High-speed internet services (DSL, cable, satellite, T lines)
• Digital Subscriber Line (DSL): High-speed digital transmission over existing telephone lines
• Cable Internet: High-speed access using cable TV coaxial lines
• T1 and T3 Lines: International digital communication standards with guaranteed delivery at specific speeds

Internet Addressing and Architecture

• IP Address: Unique 32-bit number for every internet computer (e.g., 192.168.0.1)

• Domain Name System (DNS): Converts human-readable domain names to IP addresses

• Top-Level Domain (TLD): Part of a domain name after the last dot (e.g., .com, .edu)

• Second-Level Domain: Part of a domain name before the TLD (e.g., google in google.com)

• Host Name: Specific name for a computer on a network

• Backbone Networks: High-speed transcontinental networks

• Internet Architecture Board (IAB): Defines the overall structure of the internet

• Internet Corporation for Assigned Names and Numbers (ICANN): Assigns IP addresses and manages domain names

• World Wide Web Consortium (W3C): Sets standards for web technologies

• Virtual Private Network (VPN): Secure, encrypted private network within a public network

Web Technologies

• HTTP: Communications standard for transferring web pages
• Web Server: Locates and manages stored web pages
• Search Engines: Find specific web pages
• Search Engine Optimization (SEO): Improves website ranking in search results

Web 2.0 and Beyond

• Web 2.0: Interactive, user-collaborative Internet service model
• Key features of Web 2.0: Interactivity, real-time user control, social participation, user-generated content
• Key components: Blogs, wikis, social networking sites, RSS feeds
• Web 3.0 (Future of the Internet): Advanced tools, 3D web, Internet of Things (IoT), Internet of People (IoP)

Supporting Technologies

• Cloud Computing: Storing and processing data in the cloud
• Software as a Service (SaaS): Accessing software via the web
• Ubiquitous Connectivity: Seamless connections across devices
• Interoperability: Integrated and interconnected web applications

Cellular Service Standards

• Global System for Mobile Communications (GSM): International roaming capabilities
• Code Division Multiple Access (CDMA): More efficient US standard

Wireless Computer Networks

• Bluetooth: Short-range wireless networking standard
• Wi-Fi: Wireless LAN standard
• WiMAX: Extends wireless connectivity to areas lacking Wi-Fi
• RFID (Radio Frequency Identification): Tracks goods in supply chains
• NFC (Near Field Communication): Short-range wireless data exchange
• WSN (Wireless Sensor Networks): Networks of interconnected wireless devices embedded in the physical environment

Internet Data Traffic

• Internet Data Traffic: Data transmitted over the Internet, carried by high-speed backbone networks.
• Local Connection Lines: Connect retail users to the Internet