OSI Model Flashcards
Flashcard 1
Q: What does OSI stand for?
A: Open Systems Interconnection — a conceptual model that standardizes communication functions into 7 layers.
Flashcard 2
Q: How many layers are in the OSI model, and what’s the top-to-bottom order?
A: 7 layers: Application, Presentation, Session, Transport, Network, Data Link, Physical.
Flashcard 3
Q: What is a common mnemonic to remember OSI layers (top → bottom)?
A: “All People Seem To Need Data Processing.”
Layer 7 – Application
Flashcard 4
Q: OSI Layer 7 name & role?
A: Application Layer – Closest to the end-user, provides network services like email, file transfer, web browsing.
Flashcard 5
Q: Examples of Layer 7 protocols?
A: HTTP/HTTPS, FTP, SMTP, DNS, POP3, IMAP, SNMP.
Layer 6 – Presentation
Flashcard 6
Q: OSI Layer 6 name & role?
A: Presentation Layer – Translates, encrypts, and compresses data for the Application Layer.
Flashcard 7
Q: Examples of Layer 6 functions?
A: Data formatting, character encoding (ASCII, EBCDIC), encryption (TLS/SSL), compression (JPEG, MP3, GIF).
Layer 5 – Session
Flashcard 8
Q: OSI Layer 5 name & role?
A: Session Layer – Establishes, manages, and terminates communication sessions between applications.
Flashcard 9
Q: Examples of Layer 5 functions/protocols?
A: NetBIOS, RPC, SQL session management, establishing check points in data transfer.
Layer 4 – Transport
Flashcard 10
Q: OSI Layer 4 name & role?
A: Transport Layer – Ensures complete data transfer with error-checking and flow control.
Flashcard 11
Q: Examples of Layer 4 protocols?
A: TCP (reliable, connection-oriented), UDP (faster, connectionless).
Flashcard 12
Q: Layer 4 addressing & data unit?
A: Uses port numbers (e.g., TCP 80 = HTTP). Data unit is called a Segment.
Layer 3 – Network
Flashcard 13
Q: OSI Layer 3 name & role?
A: Network Layer – Determines the best physical path for data; handles logical addressing and routing.
Flashcard 14
Q: Examples of Layer 3 protocols?
A: IP (IPv4, IPv6), ICMP, IPsec, OSPF, RIP, BGP.
Flashcard 15
Q: Layer 3 devices & data unit?
A: Devices = Routers, Layer 3 switches. Data unit = Packet.
Layer 2 – Data Link
Flashcard 16
Q: OSI Layer 2 name & role?
A: Data Link Layer – Provides error detection, MAC addressing, and controls how data is placed on the medium.
Flashcard 17
Q: What are the two sublayers of Layer 2?
A: LLC (Logical Link Control) and MAC (Media Access Control).
Flashcard 18
Q: Examples of Layer 2 protocols?
A: Ethernet (IEEE 802.3), PPP, Frame Relay, ARP.
Flashcard 19
Q: Layer 2 devices & data unit?
A: Devices = Switches, Bridges. Data unit = Frame.
Layer 1 – Physical
Flashcard 20
Q: OSI Layer 1 name & role?
A: Physical Layer – Defines the physical transmission of raw bits over a medium (cables, voltage, radio frequencies).
Flashcard 21
Q: Examples of Layer 1 technologies?
A: Ethernet cables, fiber optics, Wi-Fi radio waves, hubs, repeaters.
Flashcard 22
Q: Layer 1 data unit?
A: Bits (0s and 1s).
Extra Comparison Flashcards
Flashcard 23
Q: Which OSI layers are combined in the TCP/IP model’s Application layer?
A: Application (7), Presentation (6), and Session (5).
Flashcard 24
Q: Which OSI layers map to the TCP/IP Network layer?
A: OSI’s Network layer (3).
Flashcard 25
Q: Which OSI layers map to the TCP/IP Network Access (Link) layer?
A: Data Link (2) and Physical (1).