N10-009 Networking Concepts Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Application layer

  Why it's wrong here

  The Application layer (Layer 7) is the closest to the end-user, providing network services directly to software applications. Protocols like HTTP, FTP, SMTP, and DNS operate here, defining how applications interact with the network. This layer generates the actual application data payload but relies entirely on lower layers, particularly the Transport layer, to handle the segmentation, addressing, and reliable delivery mechanisms.

  When this WOULD be correct

  This option would be correct if the question asked: 'At which layer does the web browser's HTTP request data originate or get created?' or 'At which layer does the HTTP protocol operate?'

• ✗

  Presentation layer

  Why it's wrong here

  The Presentation layer (Layer 6) ensures that data is presented in a format that the receiving application can understand and process. This involves tasks such as data encryption and decryption, compression and decompression, and character set conversion (e.g., ASCII to EBCDIC). Its focus is on data syntax and semantics, not on the mechanics of segmenting data or adding transport-level headers for delivery.

  When this WOULD be correct

  A question asking at which layer data encryption (e.g., TLS) occurs during a secure web request would have the Presentation layer as the correct answer, as it handles encryption services.

• ✗

  Session layer

  Why it's wrong here

  The Session layer (Layer 5) establishes, manages, and terminates communication sessions between applications. Its primary function involves synchronizing dialogues, managing token passing, and checkpointing data transfers to allow for recovery from failures. While crucial for maintaining application-level conversations, it operates above the transport mechanism and does not participate in segmenting data or adding transport-specific headers.

  When this WOULD be correct

  A question asking: 'At which OSI layer does a protocol establish, maintain, and terminate a communication session between two applications?' would make Session layer the correct answer.

• ✓

  Transport layer

  Why this is correct

  The Transport layer (Layer 4) is responsible for end-to-end communication between applications, segmenting data from upper layers and reassembling it at the destination. It adds either a TCP header for reliable, connection-oriented delivery (like for HTTP) or a UDP header for unreliable, connectionless delivery. This header includes source and destination port numbers, enabling multiplexing and demultiplexing of data streams to specific applications.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The N10-009 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”