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Computer Science Each layer follows a similar process: Transmission Control Protocol/
it reads the header and trailer from its Internet Protocol model
peer layer, removes them, and passes
The Transmission Control Protocol/
the remaining information unit to the
Internet Protocol model (TCP/IP)
next higher layer. After the application
model, often known as the Internet
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layer completes these actions, the data
is delivered to the receiving software protocol suite, is used on the Internet. It
is a set of protocols that allow users to
application in computer B in the same communicate across multiple networks.
form as it was transmitted by the It always creates an environment in
application in computer A. which packets are transferred quickly
and efficiently. The OSI model is a broad
Data communication between peer
layers communication paradigm, whereas
the TCP/IP model is the model used
In the OSI model, each layer interacts by the Internet for all communication.
with other layers to utilise their services. The TCP/IP model provides end-to-
The services provided by adjacent end connectivity and specifies how
layers assist a particular OSI layer in data should be formatted, addressed,
communicating with its counterpart layer transmitted, routed, and received at the
in other computer systems. Typically, a destination. These functionalities have
layer in the OSI model communicates been organised into four layers which are
with three other layers: the layer directly known as layers of the TCP/IP model.
above it, the layer directly below it, and TCP/IP layers are the Network access,
its peer layer in other networked computer Internet, Transport, and Application
systems. For instance, the data link layer layers. Figure 3.4 illustrates the TCP/
in computer A interacts with the network IP reference model compared to the OSI
layer of computer A, the physical layer model.
of computer A, and the data link layer in
computer B, as shown in Figure 3.3.
Figure 3.3: Interactions between network Figure 3.4: Comparison of TCP/IP model
layers and OSI model
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for Advanced Secondary Schools
Computer Science Form 5.indd 128 23/07/2024 12:33
