Week 4 9 Computer Networks PDF

ITEC 101 – Introduction to Information Technology 9. COMPUTER NETWORKS Instructor: Monyrath Buntoun (Ms.) 1 LEARNING OBJECTIVES 1. Define a computer network and its purpose. 2. Describe several uses for networks. 3. Understand th...

ITEC 101 – Introduction to Information Technology 9. COMPUTER NETWORKS Instructor: Monyrath Buntoun (Ms.) 1 LEARNING OBJECTIVES 1. Define a computer network and its purpose. 2. Describe several uses for networks. 3. Understand the various characteristics of a network, such as architecture, and size. 4. Understand characteristics about data and how it travels over a network. 5. Name specific types of wired and wireless networking media and explain how they transmit data. 6. Identify the most common communications protocols and networking standards used with networks today. 2 7. List several types of networking hardware and explain the purpose of each. CONTENT I. What Is a Network? II. Networking Applications III. Network Characteristics IV. Data Transmission Characteristics V. Networking Media VI. Communications Protocols and Networking Standards VII. Networking Hardware 3 WHAT IS A NETWORK?  Network – A connected system of objects or people  Computer network – A collection of computers and other hardware devices connected together so users can share hardware, software, and data, and electronically communicate.  Computer networks are converging with telephone and other communications networks.  Networks range from small private networks to the Internet  In most businesses, computer networks are essential 4 NETWORKING APPLICATIONS The Internet – Largest computer network in the world Telephone Service  POTS (Plain Old Telephone Service) Network One of the first networks Still used today to provide telephone service to landline phones eg. In hotels to call from room to receptionists 5 NETWORKING APPLICATIONS  Mobile Phones (wireless phones) – Use a wireless network for communications Cellular (cell) Phones – Must be within range of cell tower to function Dual-mode Phones Allow users to make telephone calls using more than one communications network Cellular/Wi-Fi dual-mode phones can switch seamlessly between the Wi-Fi 6 network and a cellular network NETWORKING APPLICATIONS  Mobile Phones Satellite Phones Communicate via satellite technology Most often used by individuals such as soldiers, journalists, wilderness guides, and researchers 7 NETWORKING APPLICATIONS Television and Radio Broadcasting  Still used to deliver TV and radio content to the public  Other networks involved with television content delivery are cable TV networks, satellite TV networks, and private closed-circuit television systems Global Positioning System (GPS) Applications  Uses satellites and a receiver to determine the exact geographic location of the receiver  GPS receivers Commonly used by individuals to determine their geographic location 8 NETWORKING APPLICATIONS  GPS receivers Used on the job by surveyors, farmers, and fishermen Used to guide vehicles and equipment Used by the military to guide munitions and trucks, and to track military aircraft, ships, and submarines NETWORKING APPLICATIONS Monitoring Systems – Use networking technology to determine the current location or status of an object  RFID-based Systems – Monitor the status of objects  GPS-based Monitoring Systems Monitor the physical location of objects Vehicle and child monitoring systems  Electronic Medical Monitors – Home healthcare NETWORKING APPLICATIONS  Sensors are used in some monitoring systems Sensor networks Home automation (smart thermostats, etc.) NETWORKING APPLICATIONS Multimedia Networking  Distributing digital multimedia content, typically via a home network  Necessary networking capabilities are often built into devices being used  Might need to use multimedia networking device such as a digital media receiver or digital media streamer  Placeshifting Content Allows individuals to view multimedia content at a 12 more convenient location, eg. Plex  NETWORKING APPLICATIONS Videoconferencing, Collaborative Computing, and Telecommuting  Videoconferencing Use of computers, video cameras, microphones, and networking technologies to conduct face-to-face meetings over a network  Telepresence Videoconferencing A setup that more closely mimics a Img src: https://www.ringcentral.com/us/en/blog/telepresence-vs-video-conferencing-whats-the-difference/ real-time meeting environment 13 NETWORKING APPLICATIONS Videoconferencing, Collaborative Computing, and Telecommuting  Collaborative Computing (workgroup computing) Enables individuals to work together on documents and projects (eg. Jira, Asana, Trello, etc.)  Telecommuting Individuals work from a remote location (usually home) and communicate with their places of business and clients using networking technologies Img src: https://www.epcgroup.net/microsoft-teams-for-remote-working/ 14 Allows for employee flexibility NETWORKING APPLICATIONS Jira Board for tasks management 15 NETWORKING APPLICATIONS Telemedicine  Use of networking technology to provide medical information and services  Remote monitoring and consultations  Remote diagnosis  Telesurgery Robot assisted surgery where doctor’s physical Img src: https://www.medicaldevice-network.com/features/the- doctor-will-call-you-now-why-telemedicine-is-here-to-stay/ location is different from the patient’s and robot’s 16 Will be needed for long-term space exploration INSIDE THE INDUSTRY BOX Wireless Power / Wireless Charging  Powers/recharges devices via wireless signals and magnetic induction  Can use built-in or external charging receiver  May be built into walls, homes, cars, garage floors, etc. in the future Wireless charging electrical road in Detroit, MI, USA 17 External Charging Receiver COVID-19 CONTACT TRACING 18 DISCUSSION – COVID-19 Discuss the network applications involved in the following cases and how it works. 1. COVID-19 Contact tracing (in China) 2. COVID-19 Contact tracing (US & EU) – since US has many states and EU has many countries, focus on the integration of data across states & countries. 3. COVID-19 Contact tracing (South Korea & Taiwan) 4. COVID-19 Contact tracing (Singapore & Australia) Some points to consider: privacy and transparency, public cooperation, technology integration. 19 NETWORK CHARACTERISTICS Wired vs. Wireless Networks  Wired A network in which computers and other devices are physically connected to the network with cables Found in schools, businesses, and government facilities  Wireless A network in which computers and other devices are connected to the network without physical cables Data is typically sent via radio waves 20 Found in homes, schools, and businesses TREND BOX Stadium Wireless Networks  Professional sports venues are increasingly including wireless access and other technology  Free Wi-Fi  Seat tablet holders  In-game apps Img src: https://bemariekorea.com/kpop-lightsticks/  HD video boards  Using Bluetooth to control 21 lightstick (Concerts) NETWORK CHARACTERISTICS Network Architectures  Client-Server Networks Client – Computer or other device on the network that requests and utilizes network resources Server – Computer dedicated to processing client requests Eg. Web Server 22 NETWORK CHARACTERISTICS Network Architectures  Peer-to-Peer (P2P) Networks Central server is not used All computers on the network work at the same functional level Users have direct access to the computers and devices attached to the network Less complicated and less expensive to implement than client- server networks Internet P2P Computing – Content is exchanged over the Internet directly between users 23 Eg. Torrenting NETWORK CHARACTERISTICS 24 Img src: https://www.shiksha.com/online-courses/articles/peer-to-peer-network-all-that-you-need-to-know/  Please download and install the Slido app on all computers you use Which network applications allow the diagnosis of a patient from a distance? 25 ⓘ Start presenting to display the poll results on this slide.  Please download and install the Slido app on all computers you use What does GPS stands for? 26 ⓘ Start presenting to display the poll results on this slide.  Please download and install the Slido app on all computers you use Which of the following is an example of tools used in Collaborative Computing? 27 ⓘ Start presenting to display the poll results on this slide.  Please download and install the Slido app on all computers you use A setup that more closely mimics a real-time meeting environment refers to 28 ⓘ Start presenting to display the poll results on this slide.  Please download and install the Slido app on all computers you use Which of the following describes a peer-to-peer (P2P) network? 29 ⓘ Start presenting to display the poll results on this slide.  Please download and install the Slido app on all computers you use Which networking technology/application are commonly used for COVID-19 contact tracing? 30 ⓘ Start presenting to display the poll results on this slide.  Please download and install the Slido app on all computers you use Which wireless technology is used to controlled lightsticks in concerts? 31 ⓘ Start presenting to display the poll results on this slide. NETWORK CHARACTERISTICS Network Size and Coverage Area  Personal Area Networks (PANs)  Local Area Networks (LANs)  Metropolitan Area Networks (MANs)  Wide Area Networks (WANs) 32 NETWORK CHARACTERISTICS Network Size and Coverage Area  Personal Area Networks (PANs) Connect an individual’s personal devices Devices must be physically located close together (< 10 meters) Eg. Smartphone to a Bluetooth speaker, Laptop to a wireless monitor 33 NETWORK CHARACTERISTICS Network Size and Coverage Area  Local Area Networks (LANs) – Connect devices located in a small geographic area (eg. from inside an office to within a building)  Metropolitan Area Networks (MANs) – Cover a metropolitan area such as a city or county (eg. University Campus Network)  Wide Area Networks (WANs) Cover a large geographic area Two or more LANs connected together 34 Img src: https://www.teachoo.com/16678/3777/Question-2/category/Past-Year---3-Mark- Country level or global level (eg. the Internet) Questions/#google_vignette NETWORK CHARACTERISTICS  Intranets and Extranets Intranet Private network designed to be used by an organizations’ employees; set up like the Internet Extranet Company network accessible by authorized outsiders 35 NETWORK CHARACTERISTICS  Virtual Private Networks (VPNs) Private, secure path over the Internet that provides authorized users a secure means of accessing a private network via the Internet Uses tunneling and special encryption technology Encrypts sent and received data 36 Img src: https://www.upguard.com/blog/proxy-servers-vs-vpns NETWORK CHARACTERISTICS Remember the previous activity on searching for your IP address? Using a VPN, you can hide your real IP address and locations. 37 However, your details are still visible to the VPN providers. WHAT IS A VPN AND HOW DOES IT WORK? 38 DATA TRANSMISSION CHARACTERISTICS Bandwidth  The amount of data that can be transferred in a given period of time  Measured in bits per second (bps), Kbps (thousands), Mbps (millions), or Gbps (billions) When doing a speed test, we’re measuring our internet’s bandwidth. 39 Img src: https://www.linkedin.com/posts/matthewanayatmo_speedtest- by-ookla-the-global-broadband-activity-7123819577205002240-5Ylm DATA TRANSMISSION CHARACTERISTICS Analog vs. Digital Signals Analog Digital  Used in Conventional telephone  Data represented by two discrete systems states: 0s and 1s  Represent data with continuous waves 0 1 1 40 DATA TRANSMISSION CHARACTERISTICS Transmission Type – how bits of data travel  Serial Data sent one bit at a time, one after another, along a single path  Parallel Data sent at least one byte (8 bits) at a time with each bit in the byte taking a different path Not commonly used in a computer network (mostly used within a computer. Eg. between 41 RAM and CPU) DATA TRANSMISSION CHARACTERISTICS Transmission Timing – how data flows from sender to receiver  Synchronous Transmission Blocks of data are transferred at regular, specified intervals Most data transmissions within a computer and over a network are synchronous  Asynchronous Transmission Data is sent when ready without being synchronized Start bits and stop bits used to identify the bits that belong in each byte  Isochronous Transmission 42 Data sent at the same time as other related data DATA TRANSMISSION CHARACTERISTICS 43 DATA TRANSMISSION CHARACTERISTICS Direction of the data transmission  Simplex Transmission – Data travels in a single direction only  Half-Duplex Transmission – Data travels in either direction but only one way at a time  Full-Duplex Transmission – Data travels in both directions at the 44 same time DATA TRANSMISSION CHARACTERISTICS Delivery Method  Circuit-Switching – Dedicated path over a network is established between sender and receiver; all data follows that path  Packet-Switching – Messages are separated into small units called packets and travel along the network separately; packets are reassembled once destination is reached  Broadcasting – Data is sent out to all other nodes on the network and retrieved only by the intended recipient; primarily used with 45 LANs DATA TRANSMISSION CHARACTERISTICS - SCENARIOS 1. Live streaming a video on social media Signal: Digital Transmission Type: Serial Transmission Timing: Isochronous Transmission Direction: Full-duplex. While streaming content is one-sided, audience can react and comment on the video at that same time. **However, if the comments are moderated (eg. Instagram Live, Facebook Live, Twitch) and not seen in real-time by the streamer, 46 that would be considered as half-duplex. (eg. Youtube) DATA TRANSMISSION CHARACTERISTICS - SCENARIOS 2. Making a video call on messaging apps (Facetime, Messenger, Telegram, WhatsApp, etc.) Signal: Digital Transmission Type: Serial Transmission Timing: Isochronous Transmission Direction: Full-duplex **However, depending on how stable is the connection of both parties, it could also be automatically switched to half-duplex. 47 DATA TRANSMISSION CHARACTERISTICS - SCENARIOS 3. Communicating over a walkie talkie Signal: Analog (for the typical icom) / Newer devices supports Digital signals Transmission Type: Serial Transmission Timing: Synchronous Transmission Direction: Half-duplex 48 DATA TRANSMISSION CHARACTERISTICS - SCENARIOS 4. Communicating over text messages (SMS & IMS) Signal: Digital Transmission Type: Serial Transmission Timing: Asynchronous Transmission Direction: Full-duplex Senders and receivers can send messages at the same time. 49 NETWORKING MEDIA Wired Networking Media  Twisted-Pair Cable Pairs of insulated wires twisted together Used for telephone and network connections (LANs)  Coaxial Cable Thick center wire surrounded by insulation Used for computer networks and cable television delivery  Fiber-Optic Cable Utilizes hundreds of thin transparent clear glass or plastic fibers over which lasers transmit data as light 50 Used for high-speed communications NETWORKING MEDIA 51 NETWORKING MEDIA Wireless Networking Media  Data is sent through the air using electromagnetic waves: Radio waves (most common) – Wi-Fi, Bluetooth, Radio broadcasting, Cellular Networks, etc. Microwaves – Satellite communication. Infrared – Infrared sensors. 52 NETWORKING MEDIA Wireless Networking Media  Cellular Radio Transmissions Use cellular towers within honeycomb-shaped zones called cells Calls are transferred from cell tower to cell tower as the individual moves Cell tower forwards call to the MTSO (Mobile Telephone Switching Office) MTSO routes call to the recipient’s phone Data sent via cell phones works in similar manner The speed of cellular radio transmissions depends on the type of cellular 53 standard being used NETWORKING MEDIA 54 NETWORKING MEDIA  Microwave and Satellite Transmissions Microwaves High-frequency radio signals that are sent and received using microwave stations or satellites Microwave stations Earth-based stations that transmit signals directly to each other within a range of 30 miles Stations designed to communicate Img src: https://www.atlanticmicrowave.com/case-studies/uk-based- with satellites (television and internet atlantic-microwave-claims-worlds-first-both-satcom-and-drone-applications 55 services) are called satellite dishes NETWORKING MEDIA  Infrared (IR) Transmissions Sends data as infrared light rays Like an infrared television remote, IR requires line of sight Because of this limitation, many formerly IR devices (wireless mice, keyboards) now use RF technology IR is sometimes used to beam data between some mobile devices, game Img src: https://9gag.com/gag/aoN7Lvw consoles, and handheld gaming devices 56 COMMUNICATIONS PROTOCOLS AND NETWORKING STANDARDS Protocol  A set of rules for a particular situation  Communications Protocol – A set of rules that determine how devices on a network communicate Standard  A set of criteria or requirements approved by a recognized standards organization  Address how networked computers connect/communicate  Needed to ensure products can work with other products 57 COMMUNICATIONS PROTOCOLS AND NETWORKING STANDARDS TCP/IP  Most widely used communications protocol  Consists of two protocols Transmission Control Protocols (TCP) – Responsible for delivery of data Internet Protocols (IP) – Provides addresses and routing information  Uses packet switching to transmit data  TCP/IP support is built into almost all operating systems and IP addresses are used to identify computers and devices on networks 58 COMMUNICATIONS PROTOCOLS AND NETWORKING STANDARDS 59 COMMUNICATIONS PROTOCOLS AND NETWORKING STANDARDS Other Protocols  HTTP (Hypertext Transfer Protocol) and HTTPS (Secure Hypertext Transfer Protocol) – Used to display Web pages  FTP (File Transfer Protocol) – Used to transfer files over the Internet  SMTP (Simple Mail Transfer Protocol) and POP3 (Post Office Protocol) – Used to deliver e-mail over the Internet 60 ETHERNET (802.3) Ethernet (802.3)  Most widely used standard for wired networks  Typically used with LANs that have a star topology  Works with twisted-pair, coaxial, and fiber- optic cabling  Continually evolving Img src: https://www.forbes.com/sites/forbes-personal-shopper/2021/10/05/best-ethernet-cables/  Most common today are Fast Ethernet, Gigabit Ethernet, and 10 Gigabit Ethernet 61 ETHERNET (802.3) Power over Ethernet (PoE)  Allows electrical power to be sent along the cables on an Ethernet network along with data  Devices are not plugged into an electrical outlet  Most often used in business networks with remote wired devices  Can also be used to place networked devices Img src: https://www.truecable.com/blogs/cable- near ceilings or other locations where a nearby academy/power-over-ethernet-poe-installation-best-practices power outlet may not be available 62 ETHERNET (802.3) 63 WI-FI (802.11) Wi-Fi (802.11)  A family of wireless networking standards using IEEE standard 802.11  Current standard for wireless networks in homes and offices (wireless Ethernet)  Built into many everyday objects today  Designed for medium-range transmission; speed and distance depends on Wi-Fi standard being used, solid objects in the way, interference, etc. 64 WIMAX (802.16) WiMAX (802.16)  Standards for longer range wireless networking connections, typically MANs  Fixed WiMAX Designed to provide Internet access fixed locations (hotzones) Typical hotzone radius is between 2 and 6 miles Possible to provide coverage to an entire city by using multiple WiMAX towers  Mobile WiMAX – Mobile version of the standard 65 WIMAX (802.16) 66 CELLULAR STANDARDS Cellular Standards  First Generation – Analog and voice only  2G (Second Generation) – Digital, both voice and data, faster  3G and 4G networks Current standards Use packet switching 3G speeds are between 1 and 4 Mbps 4G speeds currently range from about 3 to 15 Mbps 67 OTHER SHORT-RANGE WIRELESS STANDARDS Bluetooth  Networking standard for very short-range wireless connections  Bluetooth 4.0 (Bluetooth Smart) is low energy so can run for years on small battery Wireless USB  Wireless version of USB designed to connect peripheral devices 68 HOW IT WORKS BOX Smart Homes  Home automation Use Bluetooth, Wi-Fi or other wireless standards to control lights, door locks, thermostats, etc.  Smart door locks can be unlocked via proximity sensors and Bluetooth 4.0  Can send temporary keys to others  Can check on status of locks and keys online NETWORKING HARDWARE Network Adapter  Used to connect a computer to a network  Also called network interface card (NIC) when in the form of an expansion card Modem  Device that enables a computer to communicate over analog networking media  Term is often used interchangeably with network adapter  Most computers and mobile devices today come with a built-in network adapter and/or modem 70 NETWORKING HARDWARE 71 NETWORKING HARDWARE Switch  Central device that connects devices in a wired network but only sends data to the intended recipient  Hub – similar but sends data to all recipients Router  Connects multiple networks: two LANs, two WANS, LAN and the Internet  Passes data to intended recipient only  Routes traffic over the Internet Wireless Access Point 72  Device used to grant network access to wireless client devices NETWORKING HARDWARE Wireless Router  Typically connects both wired and wireless devices to a network and to connect the network to the Internet  Often integrates a switch, router, and wireless access point Bridge  Used to connect two LANs together  In a home network, wirelessly connects a wired device to the network 73 NETWORKING HARDWARE 74 NETWORKING HARDWARE Repeaters Range extender  Amplify signals along a network Range Extenders  Repeaters for a wireless network Repeater  Creates a new network Antennas  Devices used for receiving or sending radio signals  Some network adapters can use an external antenna  Can be directional or omnidirectional 75  Strength measured in decibels (dB) Antennas NETWORKING HARDWARE 76 SUMMARY  Networking Applications: The Internet Telephone services (landline and mobile) Television and Radio Broadcasting GPS applications Monitoring Systems Multimedia Networking Videoconferencing, Collaborative Computing, and Telecommuting 77 Telemedicine SUMMARY  Network Characteristics: Wired vs. Wireless Network Architectures: Client-Server, Peer-to-Peer (P2P) Network Size and Coverage Area: Personal Area Networks (PANs), Local Area Networks (LANs), Metropolitan Area Networks (MANs), Wide Area Networks (WANs) Intranets and Extranets Virtual Private Networks (VPNs) 78 SUMMARY  Data Transmission Characteristics: Bandwidth Analog vs Digital Signal Serial vs. Parallel transmission Synchronous, Asynchronous, Isochronous transmission Simplex, Half-duplex, Full-duplex transmission Delivery Method: Circuit-switching, Packet-switching, Broadcasting  Networking Media Wired: Twisted-pair, Coaxial, Fiber-Optic 79 Wireless: Radio wave, Microwave, Infrared SUMMARY  Communication Protocols: TCP/IP, HTTP & HTTPS, FTP, SMTP & POP3  Networking Standard: Ethernet, WiFi, WiMAX, Cellular, Bluetooth, Wireless USB  Networking Hardware:  Provides your computer the capability to connect to a network: Network Adapter, Modem (for the Internet)  Connect/Manage network to your devices: Switch, Router, Wireless Access Point, Wireless Router, Bridge, Repeater, Range Extender, Antennas 80 REFERENCES 1. Understanding Computers: Today and Tomorrow, 14th & 15th Edition, Chapter 7 81