OSI Model

Question 1

What is the OSI model?

Answer 1

a suggested standard for communication. Describes how data is sent and received over a network. 7 Layers.

Question 2

What are the seven layers of the OSI model?

Answer 2

1. Physical
2. Data Link
3. Network
4. Transport
5. Session
6. Presentation
7. Application

Question 3

Describe layer 7

Answer 3

application layer: the software the user interacts with. generates new data within its programs and transfers them according to its protocols. IMAP, POP3, HTTP

Question 4

Describe layer 6

Answer 4

Presentation layer: data translator, manages protocol and architecture.

Protocol: guidelines under which the network operates
Architecture: determines what protocol applies

converts the data sent by the application layer of the transmitting node into an acceptable and compatible data format based on the applicable network protocol and architecture.

Question 5

Describe layer 5

Answer 5

Session layer: establishes, manages, and terminates communicative sessions

API

NETBIOS - two computers communicate shared resources over a LAN

Question 6

Describe layer 4

Answer 6

Transport layer: proves reliable process to process message delivery, error recovery, and flow control.

TCP- Telnet FTP
UDP- streaming

Question 7

Describe layer 3

Answer 7

Network Layer: moves packets from source to destination,
logical addressing, packet routing(finding shortest route)

Question 8

Describe layer 2

Answer 8

Data Link Layer: organizes bits into frames, providing node to node delivery

main three functions:
1. transmission errors
2. regulate flow of data
3. provide interface to network layer

Question 9

Describe layer 1

Answer 9

Physical Layer: transmits bits over a medium, optical and electromagnetic signals.

RJ45- LAN/ethernet
Fiber ST/SC- one transmits one receives
Fiber LC- fiber optic

Question 10

Where are error checking algorithms contained?

Answer 10

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