SIT202 Computer Networks: TCP/IP Protocol, Network Loop, Data Encapsulation, Point-to-Point Network, Modulation, Collision

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SIT202 Computer Networks
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SIT202 COMPUTER NETWORKS 2
Question 1(1)
Transport Communication protocol/ Internet protocol (TCP/IP) is a suite or a set of
communications protocols that allow two or more devices to communicate on the internet; by
providing end-to-end communication that comprises how it should be broken into packets,
addressing, its transmission and the how it will be received at the destination (Wang et al.,2016).
The TCP/IP has four layers namely application, transport, network and internet layer,
that aid in its functionalities.

SIT202 COMPUTER NETWORKS 3
The packets transmitted comprise headers with the host’s addresses for sending and
receiving. During encapsulation, as the packets travel across the TCP/IP protocol stack, the
protocols at every layer are added from the basic headers. The figure below shows the life cycle
of a packet from origin to destination.
In order for the data to travel from source to destination, every OSI layer must
communicate with its peer layer at the destination. In this process, all the protocol interchanges,
between the layers, the information is known as the Protocol Data Units (PDU).

SIT202 COMPUTER NETWORKS 4
Every layer relays on the functional services of the layers beneath it, by use of
encapsulation to convey the PDU into its data field from its upper layer. The relevant headers
that will be required for the layer to perform are added. The headers contain all the information
such as the source and destination addresses. The network layer will offer services to the
transport layer which will eventually present its data to the internetwork subsystem. This
involves encapsulation of the PDU to relay data up to the internetwork subsystem layer while
attaching the required headers to create a datagram.