OSI model (TCNO - Networking)
OSI model for test 2 TCNO/BESS
Terms in this set (32)
What does the OSI model provide?
- Provides a "visual dispay" of moving data from one network to another network
- Provides structure for troubleshooting
Which layer in the Open Systems Interconnection (OSI) reference model is closest to the user?
What are the 7 OSI layers?
- Data Link
The upper 3 layer of the OSI model is known as the ____________.
- PDU - Protocol Data Unit
what are the bottom 4 layers that break down the PDU?
- Data Link
The four lower layers of the model break down the PDU according to the mnemonic __________.
some - segments
people - packets
fear - frames
bears - bits
The Transport Layer breaks the PDU into:
The Network Layer breaks it into:
The Data Link Layer breaks it into:
The Physical Layer breaks it into:
Layers ABOVE the Transport Layer are all associated with _____.
Layers BELOW the Transport layer are all associated with _____.
- Closest to user
- user utalizes application software
- How the data is represented and formatted for data transfer
- Translation, compression, and encryption.
- Determines how two devices establish, maintain, and manage a connection, or session.
- Also performs security, name recognition, and logging so that processes can communicate over the network.
- Provides connection establishment, management, and termination, as well as acknowledgments and retransmissions.
- Ensuring that messages are delivered error-free, in sequence, and with no losses.
Transportation layer (basic info)
The Transport Layer accepts a message from the Session Layer, splits the message into smaller units (segments or packets) if needed, and passes the smaller units to the Network Layer. On the destination side, the Transport Layer reassembles the message.
- Picks the route that the data packets are to take based on network conditions, priority of service, and other factors
- It handles the addressing of the packets for delivery and makes logical addressing, routing, fragmentation, and reassembly available.
Network layer (basic info):
- The Network Layer also manages network traffic congestion. It can instruct a sending station to slow its frame transmission when the router's buffer fills up.
For example, if a data segment is too large for a router to transfer, the Network Layer fragments the frame for transmission and reassembly at the destination station.
Data Link layer:
- Provides the link through which data is communicated through hardware to be transported across a medium
- Responsible for dividing the data into frames. Frames are segments of network data that include a header, destination address, and trailer information that are sent as a unit.
Data Link layer (basic info)
The Data Link Layer communicates with network cards and performs physical addressing and data framing.
-Responsible for error detection and error handling. For example, if the data is not received properly, the Data Link Layer requests that the data be retransmitted.
- Sends signals to the network and receives signals from the network.
- Provides data encoding, signaling, data transmission, and reception.
Physical layer (basic info):
The Physical Layer is the layer where the binary data is being transmitted across some sort of media. This layer defines the physical and electrical specifications required for data transfer and is responsible for activating and maintaining the physical link between your computer and the network.
What does the Application layer do?
Serves as the way for users and application processes to access network devices..
What does the Presentation layer do?
Provides code formatting for how the PDU data is represented and formatted for data transfer.
What does the Session layer do?
Determines how two devices establish,maintain, and manage a session
What does the Transport layer do?
Ensures that messages in the form of segments are delivered error-free, in sequence, and with do losses or duplication.
What does the Network layer do?
Picks the route that data packets take
What does the Data Link layer do?
Provides the link through wich data is communicated through hardware to be transported across a medium; divides data into frames.
What does the Physical layer do?
Transfers across binary data or recieves binary data from some sort of media
What similarities does OCI have with TCP/IP?
- Layering scheme
- Packet-switching technology
What does Packet switching do?
The data is broken made into packets that contain information about the IP address of the source and destination nodes, sequence numbers, and other control information