OSI Model Flashcards
What is a protocol ?
Set of rules for formatting and processing data
Internetworking models
Organize and describe network functions
Open systems interconnection model (OSI)
Seven layers containing various types of hardware and software
Data stream=?
Transport=?
Network=?
Data Link=?
Physical=?
Application, presentation, session
Segment, Datagram
Packet
Frame
Bit
Layer 7 Application
Responsible for interfacing user application, network management services, remote access, etc.
Layer 6 Presentation
Concerned about the format, application must use a common format
What are the main services at layer 6 ?
Data conversion, character code translation, compression, encryption/decryption
Layer 5 Session
Provides logical persistent connection between peer hosts
What does the session layer do ?
Creates, monitors, and tears down sessions
Which duplex mode does the session operate with ?
Full duplex, half duplex, and simplex
Which layer is the busiest ?
Transport
What does transport create ?
End-to-end transport between peer hosts
What protocols operate at layer 4 ?
TCP and UDP
Does TCP use flags ?
Yes
What does the network layer use ?
Logical addresses (IP)
Does IP guarantee delivery ?
No only finds the best route
Devices that operate in layer 3 ?
Routers
What do routing tables help with ?
Delivering the information
What is the network layer responsible for ?
Routing data across the network
What is one of the main functions of layer 2 ?
Assigning the MAC address to communicate
Does the data link layer transmit frames or packets ?
Frames
What does layer 2 convert data into for transportation ?
Bits
Does layer 2 do error detection ?
Yes
Where does layer 2 move the data to ?
The next physically connected device
What are the two sublayers of layer 2 ?
LLC and MAC
What are the devices that operate on layer 2 ?
Switches and bridges
What does the MAC sublayer manage ?
Protocol access to the physical network medium
What is the MAC sublayer responsible for ?
Addressing and channel access control mechanisms
What controls does the LLC sublayer provide ?
Flow and error
Where does the physical layer receive its bits from ?
Data Link Layer
What are bits converted into ?
Electricity, lights, or radio waves
Are physical topologies part of layer 1 ?
Yes
What are layer 1 devices ?
Cables, connectors, hubs, modems, etc.
At which layer of the OSI Model does the encapsulation process begin ?
Application
What is the primary purpose of a networking protocol ?
To define rules and standards for data communication between network devices
