Computer Networks Overview

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Questions and Answers

What is the primary function of a server in a client/server computing model?

Creating new desktop applications

Acting as a backup for desktop computers

Performing calculations on client requests

Storing files and providing software applications (correct)

Which of the following is NOT a type of cloud service model?

Infrastructure as a Service (IaaS)

Software as a Service (SaaS)

Platform as a Service (PaaS)

Database as a Service (DaaS) (correct)

What is considered a drawback of the cloud computing model?

Reduction in overall operational costs

Improved access to data for users

Increased control over data by clients

Security risks related to data storage (correct)

What technology has fundamentally changed the primary way users access the Internet?

Smartphones Signup and view all the answers

Which of the following statements best describes the 'hourglass, layered architecture' of the Internet?

A variety of protocols that function across different layers Signup and view all the answers

Which utility program is used to test network connectivity?

Ping Signup and view all the answers

What is the main advantage of using cloud computing for businesses?

It reduces costs associated with infrastructure Signup and view all the answers

Which of the following protocols is used for email transmission?

SMTP Signup and view all the answers

What is the primary function of Packet Switching?

Slicing digital messages into packets for transmission Signup and view all the answers

Which layer is NOT a part of the TCP/IP architecture?

Session layer Signup and view all the answers

What type of address does IPv6 primarily accommodate?

128-bit addresses Signup and view all the answers

What role does the Domain Name System (DNS) serve?

Translates numeric IP addresses into human-readable domain names Signup and view all the answers

How many total addresses can IPv4 theoretically support?

4 billion Signup and view all the answers

In packet switching, what happens to packets as they are sent?

They may take different paths to the destination Signup and view all the answers

Which of the following is a characteristic of a Class C IP address?

The network is identified by the first three sets of numbers Signup and view all the answers

Which of the following accurately describes a URL?

An address used by web browsers to locate content Signup and view all the answers

Which wireless technology typically provides high-speed broadband connectivity over a limited range?

Wi-Fi Signup and view all the answers

What is the primary focus of the Internet Corporation for Assigned Names and Numbers (ICANN)?

Managing domain names and IP addresses Signup and view all the answers

What technological initiative uses balloons to provide Internet access?

Project Loon Signup and view all the answers

Which of the following best describes the Internet of Things (IoT)?

Physical objects connected to the Internet via sensors Signup and view all the answers

Who is credited with inventing the World Wide Web?

Tim Berners-Lee Signup and view all the answers

What was the first commercial web browser released in 1994?

Netscape Navigator Signup and view all the answers

What protocol is used to locate resources on the web?

Hypertext Transfer Protocol (HTTP) Signup and view all the answers

Which organization primarily focuses on facilitating the development of Internet standards?

World Wide Web Consortium (W3C) Signup and view all the answers

What is the primary purpose of a web browser?

To display web pages Signup and view all the answers

Which markup language is defined by user-created tags?

XML Signup and view all the answers

Which web browser holds the largest market share on desktop platforms?

Google Chrome Signup and view all the answers

What function does web server software primarily serve?

To deliver web pages to clients Signup and view all the answers

Which of the following is NOT a feature foundational to e-commerce?

Social media platforms Signup and view all the answers

Which of the following best describes the term 'web client'?

Any device capable of making HTTP requests Signup and view all the answers

Which company offers a significant mobile market share with its web browser?

Google Signup and view all the answers

What type of tool is e-mail classified as?

A messaging application Signup and view all the answers

What are the functions of search engines besides finding web pages that match queries?

Advertising vehicles Signup and view all the answers

What technology enables the streaming of large media files to users?

Streaming technologies Signup and view all the answers

Which of the following is a characteristic of augmented reality (AR)?

Overlaying digital objects onto the real world Signup and view all the answers

What is a primary feature of intelligent digital assistants?

Using natural language for search queries Signup and view all the answers

What is a common feature of blogs?

Chronological entries on a personal web page Signup and view all the answers

Which of the following is an example of mixed reality?

Enriched interactive experiences blending real and virtual elements Signup and view all the answers

What does the growth of broadband connections enable?

Easier access to media file downloads Signup and view all the answers

Which of the following does not describe a feature of Web 2.0 services?

Static content creation Signup and view all the answers

Study Notes

Packet Switching

Slices data into packets
Sends packets along various paths
Reassembles packets at destination
Uses routers
Cheaper and less wasteful than circuit-switching

TCP/IP

Transmission Control Protocol (TCP)
- Establishes connections between computers
- Handles packet assembly at point of transmission and reassembly at the receiving end
Internet Protocol (IP)
- Four TCP/IP layers:
  - Network interface layer
  - Internet layer
  - Transport layer
  - Application layer

Internet (IP) Addresses

IPv4
- 32-bit number
- Expressed as four sets of numbers separated by periods (example: 201.61.186.227)
- Class C address: Network identified by the first three sets, computer identified by the last set
IPv6
- 128-bit addresses
- Can handle up to 1 quadrillion addresses (as opposed to 4 billion for IPv4)

Domain Names, DNS, and URLs

Domain Name
- IP address expressed in plain language
Domain Name System (DNS)
- Translates numeric IP addresses into human-readable language
Uniform Resource Locator (URL)
- Address used by web browsers to identify content location on the web (example: https://www.cpce-polyu.edu.hk/)

Client/Server Computing

Powerful desktop computers (clients) are connected to a network with one or more servers.
Servers perform common functions for clients:
- File storage
- Software applications
- Access to printers, etc.

The Mobile Platform

Smartphones and tablets are the primary means of Internet access.
Smartphones are a disruptive technology:
- New processors and operating systems
- Over 245 million people in the U.S. access the internet through mobile phones
Tablets supplement PCs for mobile use:
- Over 170 million people in the U.S. use the internet with tablets

The Internet "Cloud Computing" Model

Businesses and individuals access computing power and software via the internet.
Three types of cloud services:
- Infrastructure as a service (IaaS): provides access to computing resources like servers and storage
- Software as a service (SaaS): delivers software applications over the internet (example: Microsoft Office 365)
- Platform as a Service (PaaS): allows users to build and deploy applications on a cloud provider's infrastructure.
Types of clouds:
- Public cloud
- Private cloud
- Hybrid cloud
Drawbacks:
- Security risks
- Shifts responsibility for storage and control to providers
Benefits:
- Radically reduces costs of building and operating websites
- Reduces cost of infrastructure, IT support, hardware, and software

Other Internet Protocols and Utility Programs

Internet Protocols:
- HTTP
- Email: SMTP, POP3, IMAP
- FTP, Telnet, SSL/TLS
Utility programs:
- Ping: tests the connectivity between two devices on a network.
- Tracert: shows the route that packets take from a source to a destination.

Internet Infrastructure

The internet's exponential growth without disruption is due to:
- Client/server computing model
- Hourglass, layered architecture:
  - Network Technology Substrate
  - Transport Services and Representation Standards
  - Middleware Services
  - Applications

Wireless Local Area Network (WLAN) -Based Internet Access

Wi-Fi (802.11 standards)
- High-speed, fixed broadband wireless LAN (WLAN)
- Wireless access point ("hot spots")
- Limited range but inexpensive
WiMax: a wireless broadband technology that provides high-speed internet access over longer distances than Wi-Fi.
Bluetooth: a short-range wireless communication technology commonly used for connecting devices like smartphones, headsets, and speakers.

Other Innovative Internet Access Technologies: Drones, Balloons, and White Space

Google's Project Loon: uses high-altitude balloons to provide internet access to remote areas.
Facebook Connectivity Lab/Acquila drone: uses solar-powered drones to provide internet access to remote areas.
Microsoft's Airband Initiative: uses "white spaces" (unused TV broadcast frequencies) to provide internet access to rural areas.
Starlink: is a satellite internet constellation developed by SpaceX that provides high-speed internet access to users around the world.

The Internet of Things (IOT)

Objects connected via sensors/RFID to the internet.
"Smart things" connect to the internet to collect data and interact with other devices.
Interoperability issues and standards must be addressed for a robust IoT ecosystem
Security and privacy concerns are present.

Who Governs the Internet?

Organizations influencing and monitoring the internet:
- Internet Corporation for Assigned Names and Numbers (ICANN)
- Internet Engineering Task Force (IETF)
- Internet Research Task Force (IRTF)
- Internet Engineering Steering Group (IESG)
- Internet Architecture Board (IAB)
- Internet Society (ISOC)
- Internet Governance Forum (IGF)
- World Wide Web Consortium (W3C)
- Internet Network Operators Groups (NOGs)

The Web

Invented between 1989 and 1991 by Tim Berners-Lee at CERN.
- HTML, HTTP, web server, web browser
1993: Mosaic web browser:
- GUI-based browser
- Runs on Windows, Macintosh, Unix
1994: Netscape Navigator: first commercial web browser.
1995: Microsoft Internet Explorer.

Hypertext

Text with embedded links
Links connect documents to each other and other data like video, sound, and animation files.
Uses Hypertext Transfer Protocol (HTTP) and URLs to locate resources on the web (example: http://megacorp.com/content/features/082602.html)

Markup Languages

Hypertext Markup Language (HTML)
- Fixed set of pre-defined markup "tags" for formatting text
- Controls the look and feel of web pages
- Used with CSS (Cascading Style Sheets)
- HTML5 is the newest version
eXtensible Markup Language (XML)
- Describes data and information
- User-defined tags

Web Servers and Web Clients

Web server software
- Allows a computer to deliver web pages to clients that request them.
- Basic capabilities: Security services, FTP, search engine, data capture
Web server
- Refers to either web server software or the physical server.
- Specialized servers: database servers, ad servers, etc.
Web client
- Any device connected to the internet that can make HTTP requests and display HTML pages.

Web Browsers

Primarily used to display web pages, but can include additional features.
- Google's Chrome: almost 70% of the desktop market; 65% of the mobile market.
  - Open source
- Mozilla Firefox: 8% desktop, >1% mobile
  - Open source
- Microsoft Edge: 7% desktop
- Internet Explorer: 6% desktop
- Apple's Safari: 4% desktop, 27% mobile

The Internet and Web: Features

Features supporting e-commerce:
- Communication tools
- Search engines
- Downloadable and streaming media
- Web 2.0 applications and services
- Virtual reality and augmented reality
- Intelligent digital assistants

Communication Tools

Email: Most-used Internet application
Messaging applications: Instant messaging
Online message boards
Internet telephony: VOIP
Videoconferencing, video chatting, telepresence

Search Engines

Identify web pages that match queries based on:
- Keyword indexes
- Page ranking (relevance, popularity)
Also serve as:
- Shopping tools
- Advertising vehicles (search engine marketing)
- Tools within e-commerce sites
Top three providers:
- Google
- Microsoft's Bing
- Verizon Media (Yahoo)

Downloadable and Streaming Media

Downloads: Increased broadband connections allow large media file downloads.
Streaming technologies:
- Enables music, video, and other large files to be sent to users in chunks
- Allows for uninterrupted playback
Podcasting
Explosion in online video viewing

Web 2.0 Features and Services

Online Social Networks: Enable communication among networks of friends and peers.
Blogs:
- Personal web pages with chronological entries
- Allow web page publishing without HTML knowledge
Wikis:
- Enable collaborative and collective document creation
- Example: Wikipedia

Virtual Reality and Augmented Reality

Virtual reality (VR):
- Immersive experience within a virtual world
- Typically uses a head-mounted display (HMD)
- Examples: Oculus Rift, Vive, PlayStation VR
Augmented reality (AR):
- Overlaying virtual objects over the real world using mobile devices or HMDs
- Example: Pokemon GO
Mixed reality (MR):
- Enhanced AR experience

Intelligent Digital Assistants

Computer search engines that use:
- Natural language
- Conversational interface, verbal commands
- Situational awareness
Can handle requests for appointments, routes, flights, event scheduling, etc.
Examples:
- Apple's Siri
- Google Now/Google Assistant
- Amazon Alexa

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Description

This quiz covers essential concepts of computer networks, including packet switching, the TCP/IP model, and the structure of IP addresses. It will test your understanding of how data is transmitted over the Internet and the roles of domain names, DNS, and URLs. Explore these foundational topics in modern networking.