ICYMI: Video Series on TCP/IP Application Protocol Design

I speak regularly at various programming conferences, and one of my favorite talks is actually on TCP/IP protocol design. This is a skill that I learned almost by accident (literally because someone had to, and no one else in the company wanted to). It’s always been one of my favorite talks, and I submit it all over the place. Most of the time it’s rejected. Which I get - protocol design is esoteric and just plain useless for most developers. But I think it’s still fun!

A bit ago I decided to take everything I had ever learned about TCP/IP protcols and live-code a server and client. So, all the knowledge that goes into my talk is also in this video series. I chose a basic chat server, since the requirements are simple and easily understood. I also wanted to try out some of the newer .NET APIs. Specifically, the final solution uses:

• async and await - naturally!
• Socket - the Berkeley-ish API for socket communication.
• System.IO.Pipelines - for low-level buffer management.
• System.Threading.Channels and IAsyncEnumerable - for asynchronous streams of messages.
• A dictionary of TaskCompletionSource instances - to implement higher-level request/response APIs.

Someday I’d like to update this to use QUIC (System.Net.Quic). Let me know if that’s something you’d be interested in!

The full video series (over 16 hours!) is available for free on YouTube, and the code is on GitHub. Enjoy!