Network Fundamentals

Transmission of raw bits over the physical medium (cables, connectors, voltages, signaling, encoding).

Frames data and provides node-to-node delivery on the same link using MAC addressing; handles error detection and media access.

Logical addressing (IP) and routing of packets between different networks; path selection.

End-to-end delivery between applications using port numbers; TCP (reliable) and UDP (best-effort) operate here; segmentation.

Layer 5 Session (establishes/manages dialogs), Layer 6 Presentation (encryption, encoding, compression), Layer 7 Application (network services to applications, e.g. HTTP, DNS).