CNIT 344 Exam 1|162 Q’s and A’s

CNIT 344 Exam 1|162 Q’s and
A’s
Components of Communication - -Message Source -> Encoder ->
Transmitter -> Transmission Medium "The Channel" -> Receiver -> Decoder
-> Message Destination

- What ISO Standard is the OSI Model? - -ISO Standard 7498.

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

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

- What does the OSI Model do? - -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? - -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? - -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 - -Physical Layer

- 2nd Layer of the OSI Model - -Data Link Layer

- 3rd Layer of the OSI Model - -Network Layer

, - 4th Layer of the OSI Model - -Transport Layer

- 5th Layer of the OSI Model - -Session Layer

- 6th Layer of the OSI Model - -Presentation Layer

- 7th Layer of the OSI Model - -Application Layer

- List all 7 layers of the OSI Model - -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? - -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? - -X.211

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

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

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

- What is the network layer of the OSI model responsible for? - -It 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? - -It converts data to packets.

Packets = reliable. Datagrams = unreliable.