Getting a Real Feel for the OSI Model — Dissecting a Single HTTP Request Into Its Seven Layers (archived 2026-07-27)

Understand the OSI model through the real thing instead of rote memorization. We assemble and dissect, in C#, the Ethernet frame carrying a single HTTP GET request, and confirm with a hex dump and Wireshark how L2 through L7 are physically nested as a byte sequence. We cover the mapping between each layer and .NET APIs (HttpClient / SslStream / Socket), troubleshooting using layer vocabulary, and correcting common misconceptions, all from a practical standpoint. Archived version of https://comcomponent.com/en/blog/osi-model-packet-anatomy/, as published on 2026-07-27. The live article is maintained and may change after this date. First published 2026-07-04.