CNIT 344 Exam 1 Questions and Answers

CNIT 344 Exam 1


Components of Communication - answer Message Source -> Encoder -> Transmitter ->
Transmission Medium "The Channel" -> Receiver -> Decoder -> Message Destination

What ISO Standard is the OSI Model? – answer ISO Standard 7498.

(ITU-T specifies X.200-X.299 Recommendations).

What does OSI stand for? - answer Open System Interconnection.

What does the OSI Model do? - answerIt 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? - answer1. 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? - answer1. 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 - answerPhysical Layer

2nd Layer of the OSI Model - answerData Link Layer

3rd Layer of the OSI Model - answerNetwork Layer

, 4th Layer of the OSI Model - answerTransport Layer

5th Layer of the OSI Model - answerSession Layer

6th Layer of the OSI Model - answerPresentation Layer

7th Layer of the OSI Model - answerApplication Layer

List all 7 layers of the OSI Model - answer7. 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? - answerIt 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? - answerX.211

What is the data link layer of the OSI model responsible for? - answerIt 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? - answerIt converts data into frames.

What are the two sub-layers in the data link layer? - answer- MAC
- LLC

Where is the data link layer of the OSI model defined? - answerX.212

What is the network layer of the OSI model responsible for? - answerIt enables
internetworking, it provides globally-unique addressing for every node in the network,
and it determines routes between source and destination networks (end-to-end with
analysis at each hop). It relies on higher layer protocols for error detection and
correction (this is UNRELIABLE).

What does the network layer convert? - answerIt converts data to packets.

Packets = reliable. Datagrams = unreliable.