1.1 The OSI Model Flashcards
What is the OSI model?
The Open Systems Interconnection Reference Model; a guide for understanding how data moves across a network.
Is the OSI model a protocol suite?
No, it is not a protocol suite; it’s a reference model with unique protocols at each layer.
What phrase can help remember the OSI layers?
“All People Seem To Need Data Processing.”
What does the Physical Layer (Layer 1) involve?
The physics of the network, including signaling, cabling, and connectors.
What does the Physical Layer (Layer 1) focus on?
it focuses on physical aspects like cabling and connectors.
What troubleshooting steps are associated with the Physical Layer? (Layer 1)
Fixing cabling issues, running loopback tests, testing/replacing cables, and swapping adapter cables.
What is the primary function of the Data Link Layer? (Layer 2)
It acts as the basic network “language” and manages communication at the data link level.
What are the protocols related to the Data Link Layer? (Layer 2)
Data Link Control (DLC) protocols and MAC (Media Access Control) addresses.
What is the Data Link Layer (Layer 2) often called?
The “switching” layer.
What does the Network Layer (Layer 3) handle?
Routing and IP, including fragmenting frames for network traversal.
What type of address is used at the Network Layer? (Layer 3)
IP address.
Which protocols operate at the Transport Layer? (Layer 4)
TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).
What does the Session Layer manage? (Layer 5)
Communication management between devices, including start, stop, and restart of sessions.
What is the function of the Transport Layer? (Layer 4)
It manages transport of data, often referred to as the “post office” layer.
What protocols are associated with the Session Layer? (Layer 5)
Control and Tunneling protocols
What is the role of the Presentation Layer? (Layer 6)
Character encoding and application encryption (e.g., SSL/TLS).
What Layer is the Presentation Layer (Layer 6) often combined with
The Application Layer.
What is the Application Layer known for? (Layer 7)
It is the layer where users interact, involving protocols like HTTP, FTP, DNS, and POP3.
What OSI layer corresponds to user-visible activity?
Layer 7 - Application Layer.
What is an example of a function at Layer 6?
Application encryption like SSL/TLS.
What type of data is managed at Layer 4?
TCP segments and UDP datagrams.
What elements are associated with Layer 3?
IP addresses, routers, and packets.
What does Layer 2 handle in terms of addressing?
MAC addresses and frames.
What is an example of a real-world application for Layer 5 (Session Layer)?
Control protocols and tunneling protocols that manage the start, stop, and continuation of communication between devices.
