7.2.12

Cards (14)

  • Protocol
    An agreed set of rules that allow two devices to communicate
  • Protocols
    • Can be for wired or wireless transfer
  • Protocols
    • Printer communicating with a computer
    • Phones/Speakers communicating wirelessly by Bluetooth
    • Webpages being transferred
    • Hardware devices communicating with a PC
    • Phone calls
    • Headphones
  • Protocols allow easier development one 'layer' at a time
  • Protocols allow multiple companies to work together
  • TCP/IP (Transmission Control Protocol/ Internet Protocol)

    • Allows devices to communicate AND has error checking facilities to ensure all packets are received
    • Is able to create and direct packets to the around a network and requests replacement copies if lost
  • TCP/IP uses
    • FTP
    • SMTP
    • IMAP
    • HTTP
  • UDP (User Datagram Protocol)

    • Has no error recovery services
    • When streaming, it is better to accept occasional lost packets and temporary dip in quality than pausing whilst replacement packets are requested
  • UDP uses
    • Online gaming
    • Streaming Media
  • HTTP (Hypertext Transfer Protocol)

    • Allows the transfer of multimedia webpages over the internet
    • This is important as the HTTP protocol allows multiple different web browsers to display and format web pages as the original author intended
  • FTP (File Transfer Protocol)

    • Allows the transfer of large files over a network
    • Uses TCP/IP, so has in-built error checking and re-transmission requests as necessary
  • DHCP (Dynamic Host Configuration Protocol)
    • Assigns IP addresses to devices on a network
    • IP address uniquely identifies a device on a network
    • Allocated when a device connects to the network
    • Single sessions only, then reallocated
  • SMTP (Simple Mail Transfer Protocol)
    Used to transfer emails between internet servers
  • IMAP (Internet Message Access Protocol)
    • Is used to upload/download email between the user's computer and an internet server
    • Emails are accessible anywhere
    • Emails are stored on the server instead of devices, which saves storage space