OS OSI

What this OSI layer question tests

This question probes your understanding of where kernel-level networking actually happens in the OSI model. It's a foundational concept in systems and networking interviews, testing whether you can map real implementation details to the seven-layer abstraction.

The kernel doesn't operate uniformly across all layers. Different parts of the network stack handle different responsibilities, and knowing which layers the kernel touches directly—versus which are userspace or hardware concerns—is essential for reasoning about performance, security boundaries, and protocol implementation. This question rewards clear thinking about the boundary between software and hardware, and between kernel and application code.

• The role of the kernel in packet processing
• Distinction between protocol layers and implementation
• Interrupt handling and device drivers
• System call boundaries in network I/O