CS 1.3 TCP/IP Model

• Packet


  A small block of data which is transported from one computer to another.
• Header


  The part of the packet which contains the sender and destination addresses, the protocol being used and a packet number.
• Payload


  The part of the packet which contains the actual data which is being sent.
• Source Address


  The address of the device where the initial message has been sent from.
• Destination Address


  The address of the device where the message is going to.
• Handshake


  An agreement which must be made between two devices, before communicating over the internet.
• Application


  The protocols in this layer determine how the data will be transferred in applications. Web browsers, email clients and file transfer protocols operate here.
• Data Link


  The layer where the network hardware is located such as the network interface card and cabling. Ethernet and Wi-Fi run here.
• Internet


  This layer routes the packets across the network using the IP protocol
• Transport


  Sets up the communication between the two devices communicating data and breaks the data in to the agreed packet size. TCP and UDP run here.
• IP Address


  A numerical address assigned to a device communicating data across the internet. This address changes.
• Error Detection


  When the receiving device detects that an error has occurred during the transmission of data. The data is then requested again.
• Packet Switching


  A data network technology. A message is broken in to packets and then sent across a network using the most suitable routes between the source and destination