Protocols

• Protocol


  A set of rules that allow devices on a network to communicate with each other
• TCP/IP


  Transmission Control Protocol / Internet Protocol - two separate protocols that combine together
• TCP


  A protocol that allows packets to be sent and received between computer systems, breaks the data into packets and reassembles them back into the original data at the destination
• IP


  A protocol in charge of routing and addressing data packets, ensures data packets are sent across networks to the correct destination, an addressing system where every device on a network is given a unique IP address
• HTTP


  Used to transfer web pages over the Internet so that users can view them in a web browser
• HTTPS


  A more secure version of HTTP that works with another protocol called SSL (Secure Sockets Layer) to transfer encrypted data
• FTP

  File Transfer Protocol, used to transfer files across a network, commonly used to upload or download files to/from a web server
• SMTP


  Simple Mail Transfer Protocol, a protocol used to send emails to a mail server and between mail servers
• POP


  Post Office Protocol, a protocol for receiving and storing emails from a mail server, will delete an email once it has been downloaded to a device
• IMAP


  Internet Message Access Protocol, a protocol for receiving and storing emails from a mail server, syncs the message with an email server so it can be accessed by different devices
• IPv4


  A 32-bit IP addressing system that allows for over 4 billion unique addresses
• IPv6


  A 128-bit IP addressing system represented in hexadecimal that allows for a mind-boggling number of unique addresses
• MAC address


  A unique hexadecimal number assigned to each network interface card inside a networked device, cannot be changed
• Networking standards


  Rules that allow computer systems to communicate across networks, ensure devices can exchange data and work together
• TCP/IP model


  A 4-layer model used to visualise the different parts of a network, each layer has a specific role
• TCP/IP model layers


  1. Application layer - allows humans and software applications to use the network

  2. Transport layer - TCP breaks the data down into data packets, ensures data is sent and received in the correct order and reassembled at the destination without errors

  3. Internet layer - IP is responsible for addressing and routing data packets, calculates the optimal route for the data to take

  4. Network access layer - Ethernet sets out the format of data packets, handles transmission errors and passes data to the physical layer
• Transferring a music file to a friend over the internet

  FTP would be used
• Sending an email to a family member in America

  SMTP would be used
• Using a webpage to enter a password securely

  HTTPS would be used
• Receiving an email from a bank

  POP3 or IMAP would be used
• Networking standards are rules that allow computer systems to communicate across networks
• Network designs are split into layers to simplify design, making it easier to modify and use