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The Concept Of Layers Ocr

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Exam code:J277

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‘

tcp-ip-stack-computer-science-revision-notes

Examiner Tips and Tricks

In the exam you are required to understand the concept of layers but you are not expected to remember the names of the layers!

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

Worked Example

TCP/IP is a set of protocols based on layers.

With regards to network protocols, define what is meant by a ‘layer’ [1]
Describe one advantage of using layers to construct network protocols [2]

Answers

Breaking up a complex task into more manageable sub tasks
Self-contained
…it allows different developers to concentrate on one aspect of the network
A layer can be taken out and edited without affecting other layers…
…it promotes interoperability between vendors and systems

Responses