CNIT 344 Exam 1 questions and answers
2026\2027 A+ Grade
Components of Communication
- correct answer Message Source -> Encoder -> Transmitter -> Transmission Medium "The Channel" ->
Receiver -> Decoder -> Message Destination
What ISO Standard is the OSI Model?
- correct answer ISO Standard 7498.
(ITU-T specifies X.200-X.299 Recommendations).
What does OSI stand for?
- correct answer Open System Interconnection.
What does the OSI Model do?
- correct answer It defines 7 layers that describe the complete application-based communications
between any two systems. It provides open interconnections between layers, such that multi-vendor
environments can be supported.
What are the Rules for Communication for the OSI Model?
- correct answer 1. The communication between layers is handled in a specified (defined) manner.
2. Each layer is only able to communicate with its adjacent layers.
3. Each layer relies on the layers below it to perform their specified function.
4. Each layer relies on the layers above it to perform their specified function.
,What are some benefits to the OSI Model?
- correct answer 1. Breaks network communication into smaller, more manageable parts. Prevents
changes in one layer from affecting other layers.
2. Standardizes network components to allow multiple vendor development and support.
3. Allows different types of network hardware and software to communicate with each other.
1st Layer of the OSI Model
- correct answer Physical Layer
2nd Layer of the OSI Model
- correct answer Data Link Layer
3rd Layer of the OSI Model
- correct answer Network Layer
4th Layer of the OSI Model
- correct answer Transport Layer
5th Layer of the OSI Model
- correct answer Session Layer
6th Layer of the OSI Model
- correct answer Presentation Layer
7th Layer of the OSI Model
- correct answer Application Layer
List all 7 layers of the OSI Model
- correct answer 7. Application
6. Presentation
, 5. Session
4. Transport
3. Network
2. Data Link
1. Physical
What is the physical layer of the OSI model responsible for?
- correct answer It is responsible for the transmission and receipt of the bit stream to/from nodes. It is
solely concerned with signaling techniques (such as activating, maintaining, and terminating the physical
circuit).
Where is the physical layer of the OSI model defined?
- correct answer X.211
What is the data link layer of the OSI model responsible for?
- correct answer It is responsible for providing point-to-point validity of the data via point-to-point
checking/correction, and it is responsible for the procedures and protocols for reliably operating the
communication links.
It has an independent address architecture from other layers.
What does the data link layer convert?
- correct answer It converts data into frames.
What are the two sub-layers in the data link layer?
- correct answer - MAC
- LLC
Where is the data link layer of the OSI model defined?
- correct answer X.212
What is the network layer of the OSI model responsible for?
- correct answer It enables internetworking, it provides globally-unique addressing for every node in the
2026\2027 A+ Grade
Components of Communication
- correct answer Message Source -> Encoder -> Transmitter -> Transmission Medium "The Channel" ->
Receiver -> Decoder -> Message Destination
What ISO Standard is the OSI Model?
- correct answer ISO Standard 7498.
(ITU-T specifies X.200-X.299 Recommendations).
What does OSI stand for?
- correct answer Open System Interconnection.
What does the OSI Model do?
- correct answer It defines 7 layers that describe the complete application-based communications
between any two systems. It provides open interconnections between layers, such that multi-vendor
environments can be supported.
What are the Rules for Communication for the OSI Model?
- correct answer 1. The communication between layers is handled in a specified (defined) manner.
2. Each layer is only able to communicate with its adjacent layers.
3. Each layer relies on the layers below it to perform their specified function.
4. Each layer relies on the layers above it to perform their specified function.
,What are some benefits to the OSI Model?
- correct answer 1. Breaks network communication into smaller, more manageable parts. Prevents
changes in one layer from affecting other layers.
2. Standardizes network components to allow multiple vendor development and support.
3. Allows different types of network hardware and software to communicate with each other.
1st Layer of the OSI Model
- correct answer Physical Layer
2nd Layer of the OSI Model
- correct answer Data Link Layer
3rd Layer of the OSI Model
- correct answer Network Layer
4th Layer of the OSI Model
- correct answer Transport Layer
5th Layer of the OSI Model
- correct answer Session Layer
6th Layer of the OSI Model
- correct answer Presentation Layer
7th Layer of the OSI Model
- correct answer Application Layer
List all 7 layers of the OSI Model
- correct answer 7. Application
6. Presentation
, 5. Session
4. Transport
3. Network
2. Data Link
1. Physical
What is the physical layer of the OSI model responsible for?
- correct answer It is responsible for the transmission and receipt of the bit stream to/from nodes. It is
solely concerned with signaling techniques (such as activating, maintaining, and terminating the physical
circuit).
Where is the physical layer of the OSI model defined?
- correct answer X.211
What is the data link layer of the OSI model responsible for?
- correct answer It is responsible for providing point-to-point validity of the data via point-to-point
checking/correction, and it is responsible for the procedures and protocols for reliably operating the
communication links.
It has an independent address architecture from other layers.
What does the data link layer convert?
- correct answer It converts data into frames.
What are the two sub-layers in the data link layer?
- correct answer - MAC
- LLC
Where is the data link layer of the OSI model defined?
- correct answer X.212
What is the network layer of the OSI model responsible for?
- correct answer It enables internetworking, it provides globally-unique addressing for every node in the
