CNIT 344 EXAM 1 QUESTIONS AND ANSWERS
Components of Communication - Answers -Message Source -> Encoder -> Transmitter
-> Transmission Medium "The Channel" -> Receiver -> Decoder -> Message
Destination
What ISO Standard is the OSI Model? - Answers -ISO Standard 7498.
(ITU-T specifies X.200-X.299 Recommendations).
What does OSI stand for? - Answers -Open System Interconnection.
What does the OSI Model do? - Answers -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? - Answers -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? - Answers -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 - Answers -Physical Layer
2nd Layer of the OSI Model - Answers -Data Link Layer
3rd Layer of the OSI Model - Answers -Network Layer
4th Layer of the OSI Model - Answers -Transport Layer
5th Layer of the OSI Model - Answers -Session Layer
, 6th Layer of the OSI Model - Answers -Presentation Layer
7th Layer of the OSI Model - Answers -Application Layer
List all 7 layers of the OSI Model - Answers -7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data Link
1. Physical
How do re-transmit requests work? - Answers -By sequence # and ACK.
What does the transport layer convert? - Answers -It converts data into messages or
segments.
Where is the transport layer of the OSI model defined? - Answers -X.214
What is the session layer of the OSI model responsible for? - Answers -It establishes,
maintains, and terminates host-to-host interactive sessions. It is used to uniquely
identify a service, application, or function on a host via ports.
What is a socket? - Answers -Port + Layer 3 (Network) Address
Where is the session layer of the OSI model defined? - Answers -X.215
What is the presentation layer of the OSI model responsible for? - Answers -It is
responsible for managing the way data is presented.
It is NOT the GUI.
What are some code conversions/translations? - Answers -ASCII, EBCDIC, Unicode
Where is the presentation layer of the OSI model defined? - Answers -X.216
What is the application layer of the OSI model responsible for? - Answers -It provides
the interface between user applications and network's services (usually through
network-capable APIs).
This does NOT include actual user applications.
What are some application protocols that exist at the application layer? - Answers -
HTTP, SIP, Telnet/SSH, SMTP, and Routing Protocols.
Where is the application layer of the OSI model defined? - Answers -X.207
Components of Communication - Answers -Message Source -> Encoder -> Transmitter
-> Transmission Medium "The Channel" -> Receiver -> Decoder -> Message
Destination
What ISO Standard is the OSI Model? - Answers -ISO Standard 7498.
(ITU-T specifies X.200-X.299 Recommendations).
What does OSI stand for? - Answers -Open System Interconnection.
What does the OSI Model do? - Answers -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? - Answers -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? - Answers -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 - Answers -Physical Layer
2nd Layer of the OSI Model - Answers -Data Link Layer
3rd Layer of the OSI Model - Answers -Network Layer
4th Layer of the OSI Model - Answers -Transport Layer
5th Layer of the OSI Model - Answers -Session Layer
, 6th Layer of the OSI Model - Answers -Presentation Layer
7th Layer of the OSI Model - Answers -Application Layer
List all 7 layers of the OSI Model - Answers -7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data Link
1. Physical
How do re-transmit requests work? - Answers -By sequence # and ACK.
What does the transport layer convert? - Answers -It converts data into messages or
segments.
Where is the transport layer of the OSI model defined? - Answers -X.214
What is the session layer of the OSI model responsible for? - Answers -It establishes,
maintains, and terminates host-to-host interactive sessions. It is used to uniquely
identify a service, application, or function on a host via ports.
What is a socket? - Answers -Port + Layer 3 (Network) Address
Where is the session layer of the OSI model defined? - Answers -X.215
What is the presentation layer of the OSI model responsible for? - Answers -It is
responsible for managing the way data is presented.
It is NOT the GUI.
What are some code conversions/translations? - Answers -ASCII, EBCDIC, Unicode
Where is the presentation layer of the OSI model defined? - Answers -X.216
What is the application layer of the OSI model responsible for? - Answers -It provides
the interface between user applications and network's services (usually through
network-capable APIs).
This does NOT include actual user applications.
What are some application protocols that exist at the application layer? - Answers -
HTTP, SIP, Telnet/SSH, SMTP, and Routing Protocols.
Where is the application layer of the OSI model defined? - Answers -X.207
