Protocol implementation in a vertically structured operating system

A vertically structured operating system is one in which neither the "kernel" nor "servers" perform work on behalf of applications-the former because it exists only to multiplex the CPU, and the latter in order to avoid Quality of Service interference between the applications. Instead, wherever possible, the applications perform all of their own processing. Such a vertical structure provides many advantages for applications but leads to some interesting problems and opportunities for protocol stack implementation. This paper describes the techniques we used in our protocol implementation and the benefits that the vertical structure provided.