Network Layers Edexcel

The Concept of Layers

• Networks rely on many complex parts all working together at the same time, from different types of network, the different operating models, the internet, wired and wireless to encryption, addressing and protocols

• Managing the complexity of networks is helped with the use of layers

What is a layer?

• A layer is a sub part of a more complex task

• Dividing network tasks into layers reduces the complexity and makes each layer more manageable

• An example of layers can be seen in the TCP/IP protocol which uses a 4-layer model known as a ‘stack‘

What are the advantages of layers?

• Layers are self-contained which makes managing, repairing and upgrading easier as each layer can be worked on independent of other layers

• Layers allow for focus on specific parts of a protocol without affecting other layers

• Promotes data exchange (interoperability) between hardware and software

TCP/IP Model

What is the TCP/IP model?

• The TCP/IP model is made up of two protocols (TCP & IP), containing 4 layers, that work together to package, address, transmit and receive data on a wide area network (Internet)

• There are four layers that make up the TCP/IP protocol stack:

  • Application

  • Transport

  • Internet

  • Link

• Different protocols (opens in a new tab)operate on different layers

• Data is split up into packets for transmission across the internet

• A packet consists of:

• Data passes down through layers of the stack when it is being sent and up through the layers when it is received