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D481 OA Terminology Questions with Answers (100%
Correct Answers
TCP/IP Application Layer 4 Answer: The top of the TCP/IP Reference
Model, which maps to OSI Layers 5, 6, and 7. This interacts with
applications that need to gain access to network services.
TCP/IP Transport or Host-to-Host Layer 3 Answer: Provides end-to-
end delivery, which maps to OSI Layer 4. This layer segments the data
and adds a checksum to properly validate data to ensure that it has not
been corrupted.
TCP/IP Network or Internet Layer 2 Answer: Handles the routing of
packets as they move around the network. It maps to Layer 3 of the
OSI model.
TCP/IP Physical or Network Access Layer 1 Answer: Resides at the
lowest layer of the TCP/IP model and is the point at which the higher-
layer protocols interface with the network transport media. When
compared to the OSI model, this layer corresponds to OSI Layer 1 and
Layer 2.
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OSI Application Layer 7 Answer: Responsible for interacting with end
users. This Layer includes all programs on a computer that interact
with the network; for example, your email software is included
because it must transmit and receive messages over the network. A
simple game like Solitaire doesn't fit here because it does not require
the network to operate.
OSI Presentation Layer 6 Answer: This is responsible for the coding of
data. This Layer includes file formats and character representations.
From a security perspective, encryption generally takes place at this
layer.
OSI Session Layer 5 Answer: This is responsible for maintaining
communication sessions between computers. This Layer creates,
maintains, and disconnects communications that take place between
processes over the network.
OSI Transport Layer 4 Answer: This is responsible for breaking data
into packets and properly transmitting them over the network. Flow
control and error checking take place here. TCP operates in this layer
OSI Network Layer 3 Answer: This is responsible for the logical
implementation of the network. One important feature of this Layer is
© 2025 All rights reserved
D481 OA Terminology Questions with Answers (100%
Correct Answers
TCP/IP Application Layer 4 Answer: The top of the TCP/IP Reference
Model, which maps to OSI Layers 5, 6, and 7. This interacts with
applications that need to gain access to network services.
TCP/IP Transport or Host-to-Host Layer 3 Answer: Provides end-to-
end delivery, which maps to OSI Layer 4. This layer segments the data
and adds a checksum to properly validate data to ensure that it has not
been corrupted.
TCP/IP Network or Internet Layer 2 Answer: Handles the routing of
packets as they move around the network. It maps to Layer 3 of the
OSI model.
TCP/IP Physical or Network Access Layer 1 Answer: Resides at the
lowest layer of the TCP/IP model and is the point at which the higher-
layer protocols interface with the network transport media. When
compared to the OSI model, this layer corresponds to OSI Layer 1 and
Layer 2.
© 2025 All rights reserved
, 2
OSI Application Layer 7 Answer: Responsible for interacting with end
users. This Layer includes all programs on a computer that interact
with the network; for example, your email software is included
because it must transmit and receive messages over the network. A
simple game like Solitaire doesn't fit here because it does not require
the network to operate.
OSI Presentation Layer 6 Answer: This is responsible for the coding of
data. This Layer includes file formats and character representations.
From a security perspective, encryption generally takes place at this
layer.
OSI Session Layer 5 Answer: This is responsible for maintaining
communication sessions between computers. This Layer creates,
maintains, and disconnects communications that take place between
processes over the network.
OSI Transport Layer 4 Answer: This is responsible for breaking data
into packets and properly transmitting them over the network. Flow
control and error checking take place here. TCP operates in this layer
OSI Network Layer 3 Answer: This is responsible for the logical
implementation of the network. One important feature of this Layer is
© 2025 All rights reserved
