This tutorial provides just basic network programming knowledge, in order to build high performance client - server solution you need more than that.
Clean and scalable server architecture should be designed. Not easy task at all
I would suggest to take a look at XF.Server component for server solutions written in .NET / C# / VB.NET
The only thing that should be added is the server's business logic. I've tried the component, it has nice design and interesting solutions to get maximum performance.