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Flashcards

Topic 3 Review

고예원 일본 Computer Science International Baccalaureate Inglês 73 flashcards

Topic 3 Review

Flashcards do conjunto (73)

  1. 13.1.1 Identify different types of networksLAN / WAN / GAN / PAN / P2P / WLAN / SAN / VLAN / VPN / Internet / Extranet / Intranet
  2. 2LANlocal area network in which the nodes are close together(school,office)
  3. 3WANworld area network in which the nodes are spread out over larger geographic area
  4. 4GANglobal area network where the nodes are spread out more globally (internet)
  5. 5PANpersonal area network which consists of computers,mobile...(Computer-printer relationships)
  6. 6P2Ppeer-to-peer network in which computer can act as a server for the other(Skype,Mail...)
  7. 7WLANwireless local area network it is the same as LAN,but wireless(Wi-Fi)
  8. 8SANstorage are network which provide dedicated access to storage
  9. 9VLANvirtual local area network is a logical concept not physical
  10. 10VPNvirtual personal network is creates an encrypted connection over a less secure network
  11. 11Interneta network of networks(www,mail,skype,viber)
  12. 12Extranetan intranet that can be partially accessed by authorized outside users
  13. 13Intraneta local or restricted communications network, especially a private network created using World Wide Web software
  14. 143.1.2 Outline the importance of standards in the construction of networksStandards play an important role in network construction.
    If standards are not kept incompatibility issues will arise. For example data that is shared in the network should be in a language that is supported by all users.
    Also standard and similar cables have to be used in order to have similar types of data. International Organization for Standardization (ISO) is an organization that creates those kind of standards. For example, it has created ASCII and then changed it to Unicode so that all devices can support the use of all languages.
  15. 153.1.3 Describe how communication over networks is broken down into different layers.1. Physical 2. Data link 3. Network 4. Transport 5. Session 6. Presentation 7. Application3.1.3 Describe how communication over networks is broken down into different layers.
  16. 16Physical layerChecks the presence of cables
  17. 17Data link layerChecks the physical address of the device (MAC)
  18. 18Network layerChecks the presence of the IP address
  19. 19Transport layerDecides the way how the data will be transported (TCP- transmission control protocol)
  20. 20Session layerCreates a bridge between 2 computers by checking the presence of both devices
  21. 21Presentation layerConverts data from binary format to user-friendly format or vice versa
  22. 22Application layerPresents the information in a user-friendly way (HTML)
  23. 233.1.4 Identify the technologies required to provide a VPN [Definition of VPN]VPN: A secure network that uses primarily public communication system, such as the Internet, to extend a private network.
  24. 24[Requirements]1. A LAN that is connected to the internet.
    2. One computer outside of the LAN that is also connected to the internet.
    3. VPN client and server running on the lone machine and the original LAN
    4. Internet connection
  25. 253.1.5 Evaluate the use of a VPN. [Advantages]1. Employees can work from anywhere by connecting to the VPN of the company
    2. Branches of the company are able to connect to the headquarters of the company.
    3. It is cheap
    4. It is reliable
    5. It saves time and increases the productivity
  26. 26[Disadvantages]1. It has a low speed
    2. Compatibility issues can arise between the users of the network
  27. 273.1.6 Define the terms: protocol & data packet [Protocol]Set of rules for data communication.
  28. 28[Data Pocket]combination of bits in some lengths send across the network.
  29. 29[Data]Anything in a form suitable for use with computer such us binary. Typically data meaningless.
  30. 30[Packet]A small unit of data in network communication.
  31. 313.1.7 Explain why protocols are necessary [Protocols]Protocols are the set of rules computers follow when communicating across a network. Without them, no information can be transmitted as computers don't know how to interpret the signals coming through the network.
  32. 32Essential Functions of Protocols [Data Integrity]Means that the data has not been changed/corrupted deliberately or accidentally during the transmission. Uses checksum mechanisms.
    Source integrity – Means that the identity of the sender has been verified. Digital signatures are used to prove source integrity.
  33. 33[Source Integrity]Means that the identity of the sender has been verified. Digital signatures are used to prove source integrity.
  34. 34[Flow Control]Networks have limited memory and bandwidth. The transport layer is responsible for taking advantage of its protocols and facing situations where an overload occurs. These protocols can request form a sending application to slow down the data flow rate. The transport layer controls the reliability of a given link through flow control.
  35. 35[Congestion Management]Congestion happens when the request on the network resources exceeds the offered capacity.
  36. 36[Deadlock prevention]A Deadlock is a situation in which two or more network competing actions are waiting for each other to finish, and thus neither ever does creating a deadlock. The persistence timer is used to resolve the situation.
  37. 37[Error Checking]Process of checking for errors
  38. 38[Error Correction]Ability to correct errors
  39. 393.1.8 Explain why the speed of data transmission across a network can varyReasons why speed may vary:
    1. The speed may vary at different times of the day
    2. The speed may vary depending on the distance. Rural and urban areas will have different speeds with rural being the slowest and urban being the fastest.
    3. The speed may vary depending on your specific internet provider
    4. The speed may vary depending on the quality of the cable that is used (Fibre vs Copper)
    5. Speed may vary depending on which connection method is used ( WIFI, UTP, CABLE)
  40. 403.1.9 Explain why compression of data is often necessary when transmitting across a networkAll networks have limited bandwidth. Compressing a file reduces its size which reduces bandwidth uses and results in faster transfer speeds.
  41. 41[Two Types of Compression][Lossy Compression]
    Some of the information is lost to an acceptable degree. There is no way to get the original file background
    Examples : JPEG, MP3, MP4
    [Loseless Compression]
    The compression method reduces the number of bits by identifying and eliminating any statistical redundancy. There is no loss of information during loseless compression. Examples = ZIP, GIF, PNG
  42. 42[Use of Compression][Backups and Archiving]
    So backup files don't take as much space as the original ones.
    [File Transfer]
    If the file is smaller it will take less time to upload/download.
    [Web use of media Files]
    Download of MP3 files(smaller music files)
    [File encryption and protection]
    Compressed files which their data is mixed up and has no meaning.
  43. 433.1.10 Outline the characteristics of different transmission media [Wired][Copper cable ( metal conductor)]
    most common kind of cabling in computer networks
    [Coaxial cable]
    consists of two copper conductors it was used in computer networks, as well as to carry TV signals. Low cost of installation.
    [Unshielded Twisted Pair Cable (UTP)]
    very popular in LANs. Easy to install. Prone to electrical interference. Low cost of installation. Good for short distances.
    [Shielded Twisted Pair Cable]
    Same as UTP but harder to install and less prone to electrical interference.
    [Fiber Optic Cable]
    Optical cable that carries a beam of light, Very expensive, Offers very high speeds, Needs fewer repeaters. Extremely secure. Used for data and telephone lines
  44. 44[Wireless][Microwave Radio]
    used extensively for mobile telephone networks and LANs, info is carried through the air.
    [Satellites]
    use microwave signals
    [Infrared]
    used only for very short distances, requires line of site, very secure
    [RFID]
    uses various radio technologies, active RFID needs internal power. Passive RFID needs no power source.
    [Bluetooth]
    bluetooth devices use microwave radio to exchange data, transmit at very low power levels, regularly changing frequiencies.
  45. 45[Characteristics of Transmission Media][Characteristics of Transmission Media]
  46. 463.1.11 Explain how data is transmitted by packet switchingData packet is a unit of information.
    Packet switching refers to a communication method used in computer networks in which data are grouped into packets. The original file is divided into packets before transmission and each packet may follow a different path to each destination. Each packet is sent individually, possibly reaching the destination via different routes. With packet switching the communication channel can be used more efficiently and delays are minimized.
  47. 473.1.12 Outline the advantages and disadvantages of wireless networks [Advantages]Does not take space or time to lay the cable's.
    No extra cost for cables.
    You can bring your own device
    Increased mobility
    Easy to use
    Easy installation
    Expansion is easier
    Guest usage
  48. 48[Disadvantages]Risk of cancer
    2-50x slower than wired communication
    Less stable
    Car crashes, because of talking on mobile
    Security issues
    Weak privacy
    High error rates
    Can be unsustainable because of weather
    The distance that wireless networking covers is smaller
    Can be used to steal data
  49. 493.1.13 Hardware and software components of a wireless network [Hardware] Modemallows you to connect to the internet
  50. 50[Hardware] Wireless routerActs the same as a wired router, but in some cases will also act as a WAP (wireless access point), WAP allows data transfer between a device and a network, wireless router will usually have LAN jacks for wired devices.
  51. 51[Hardware] Wireless network adapteralso known as a wireless NIC, it is required for any devices that don’t have wireless capabilities.
  52. 52[Hardware] device that can connect to the networkPC ,mobile ,games console
  53. 53[Hardware] Wireless antennasAccess points and routers will often utilize WiFi antennas that significantly increase the effective communication area of a network. They are fixed, optional or removable.
  54. 54[Hardware] Wireless repeatersignal booster, connects to a router or access point. Purpose is to receive an existing signal and to rebroadcast it.
  55. 55[Hardware] Ethernet to wireless access point or to wireless repeaterusing ethernet cables to carry signal to the wireless repeater or WAP.
  56. 56[Hardware] Ethernet over powerline to wireless repeater or WAPit uses power lines to carry the signal to the wireless repeater or WAP
  57. 57[Software] DHCPdynamic host configuration protocol is a network protocol that allows a server to automatically assign an IP address to a client device.
  58. 58[Software] Software Firewalla network security system that determines what data comes in and goes out of a network or pc.
  59. 59[Software] Name/SSIDA service set identification (SSID) is a set of 32 alphanumeric characters, it is used to differentiate one WLAN from another. It is case sensitive
  60. 60[Software] NIC driversa network interface card driver is a driver for the NIC cards, the driver operated the hardware of the card, it acts as a translator between the OS and the NIC
  61. 61[Software] OSOperating system handles system resources and is responsible for managing all protocols software and hardware that have to cooperate so that a network can exist and function.
  62. 62[Software] Security softwareIncludes all software that prevents unauthorized access, use , disclosure, disruption, modification, perusal, inspection, recording or destruction of data
  63. 63[Software] WAPWireless application protocol specifies a set of protocols for accessing information over a mobile wireless network. It allows users to access the internet, exchange emails and surf the web
  64. 64[Software] Web Browseran application software that is used to find retrieve and display content on the WWW. Includes, text images audio.
  65. 653.1.14 Describe the characteristics of wireless networks [WiFi]• Also called Wireless LAN (WLAN) • Used in laptops/mobile devices to connect wirelessly to home network
    • Most preferred network type to implement a home network
    • Allows relatively slow to fast data transmissions (depending on the version)
    • Backwards compatible with most older WiFi standards (a/b/g/n)
    • Small transmitting radius makes it suited for homes, usually <20m
  66. 66[WiMAX]• WiMAX = Worldwide Interoperability for Microwave Access
    • Designed for large distance high speed internet access
    • Relatively cheap method of providing internet over a large area - suited for poorer countries
    • Rivaled by Long Term Evolution (LTE) standard
    • Can be used as a form of wireless variant of DSL phone transmission lines
  67. 67[3G (Third Generation)]• The primary way mobile phones access the internet today
    • Allows the tunneling of phone lines (mobiles don't have to switch back to phone network when receiving a call
    • Relatively fast
  68. 68[LTE ( long term evolution)]4G data network
    High speed data
    smartphones and mobile data terminals
    large capacity
    fast
  69. 69[WiMAX vs LTE]Both considered 4G technologies and both are IP technologies
    They use different channels
    LTE is compatible with 3G and 2G while WiMAX is not
    Building an LTE network is more expensive
    LTE allows much greater speed for mobile users
    WiMAX is less popular and less widespread than LTE
    WiMAX is considered a better choice for low-cost network installation in developing countries
  70. 703.1.15 Different method of network security [Why do networks need security?]Because they need to protect from hackers intruders or unauthorized users, which can cause harm in multiple ways including and not limited to:
    Disabling operations
    Inserting viruses or malicious code
    Steal identities
    Steal devices
    Steal sensitive information
    Cause a DOS attack (denial of service)
  71. 71[Types of network security] Encryptionuses complex math to alter a message into a form that is not understandable to an unauthorized person.
  72. 72[Types of network security] 2 types of EncryptionSymmetric-key encryption, also known as single key or secret key encryption, both the sender and receiver will use the same key to encrypt a packet before it is sent. (DES, AES)
    Public-key encryption, also known as asymmetric key encryption, uses two keys the public key is used for encryption while the private key is used for decryption. This type of encryption is used on the internet. ( SSL, TLS)    [Types of network security] 2 types of Encryption
  73. 733.1.16 Advantages and disadvantages of each method of network security.3.1.16 Advantages and disadvantages of each method of network security.

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International Baccalaureate Computer Science FlashCards sobre Topic 3 Review, criado por 고예원 일본 em 16-01-2023.
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