Question

Difficulty: HardOSI Model Layers and Functions

During a technical audit of a heterogeneous enterprise application stack, a network analyst is reviewing how data payloads are prepared for secure transmission across dissimilar host architectures. The specification requires data syntax normalization, character encoding conversion, and payload encryption prior to session establishment. Which of the following operational functions are performed strictly at Layer 6 (Presentation Layer) of the OSI model? (Select TWO)

  1. Converting character encodings between incompatible formats, such as translating EBCDIC to ASCII or UTF-8Answer
  2. Performing cryptographic data encryption and decryption, as well as application payload compressionAnswer
  3. C
    Establishing dialogue control checkpoints and managing half-duplex or full-duplex session synchronization
  4. D
    Multiplexing distinct process communication streams using TCP/UDP port socket pairs and managing segment sequence numbers

Answer

The Presentation Layer (Layer 6) is responsible for data translation (such as character set conversion between EBCDIC and ASCII/UTF-8) and data formatting operations including encryption/decryption and compression.
The Presentation Layer (Layer 6) serves as the syntax translator for the OSI model. Its core responsibilities include character code translation (such as ASCII to EBCDIC or UTF-8), data structure formatting (such as XML/JSON syntax normalization), data compression, and cryptographic encryption/decryption of application data.

Step-by-Step Solution

1
Identify the specific OSI layer requested in the scenario
The scenario focuses on Layer 6 (Presentation Layer) functions.
Layer 6 acts as the syntax translator of the network stack, ensuring data sent from the application layer of one system can be read by the application layer of another.
2
Evaluate the options against Layer 6 duties
Character set translation (EBCDIC to ASCII/UTF-8) and payload encryption/compression belong to Layer 6.
These tasks handle the format, structure, and representation of data.
3
Differentiate adjacent OSI layer duties
Dialogue control checkpoints belong to Layer 5 (Session), and port socket multiplexing belongs to Layer 4 (Transport).
Layer 5 manages active session state and synchronization, while Layer 4 manages end-to-end transport and process addressing.

Key Concept

OSI Layer 6 (Presentation Layer) Data Formatting and Encryption Functions
Estimated Time:2m 0s
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