Question

Network support layers of OSI are: (A) Network Layer (B) Physical Layer (C) Presentation Layer (D) Data Link Layer Choose the correct answer from the options given below:

• A. (A), (B) and (D) only
• B. (A), (C) and (D) only
• C. (A), (B), (C) and (D)
• D. (B), (C) and (D) only

Hint:

Remember the OSI model layers from bottom to top. The bottom three (Physical, Data Link, Network) are the "Network Support" layers, which handle the nuts and bolts of data transmission.

Answer 1

The Correct Option is A

Step 1: Understand the grouping of OSI layers. The seven layers of the OSI model are often grouped into two categories: \[\begin{array}{rl} \bullet & \text{Network Support Layers (or Lower Layers): These layers deal with the physical aspects of moving data from one device to another. They are concerned with hardware, cables, and network interfaces.} \\ \bullet & \text{User Support Layers (or Upper Layers): These layers deal with interoperability among software systems and provide services to the end-user applications.} \\ \end{array}\]

Step 2: Classify the layers. The Network Support Layers are: Layer 1 (Physical Layer), Layer 2 (Data Link Layer), and Layer 3 (Network Layer). The Transport Layer (Layer 4) is the bridge between the two groups. The User Support Layers are: Layer 5 (Session), Layer 6 (Presentation), and Layer 7 (Application).

Step 3: Select the correct options. Based on this classification, the Network Support Layers from the list are the Network Layer (A), Physical Layer (B), and Data Link Layer (D). The Presentation Layer (C) is a User Support Layer.