Re: [Hist Trivia] IP Protocol Layers

[Joe Touch <touch at ISI.EDU>]

Randy Bush wrote:
> 
> > I.e., layering is, IMO at least, a model. Fine for describing things, but
> > not necessarily a good blueprint for an implementation.
> 
> compilation systems can be constructed which will procuce efficient inlined
> code for nicely modularized (layered) source.  just not for programs which
> use type-free pointers and similar analysis-defeating features.
> 
> randy

They can also do disastrous things, e.g., creating in-lined chunks
that thrash the instruction cache.

It's not just the layers that need to be spec'd, but the
interfaces between them. Even then all you have is a specification,
not necessarily an appropriate design for an implementation.

Greg Minshall wrote:
> 
> ...i value protocol model AND mechanism correctness over
> some amount of last ounce optimization.

It's also not just about optimization - sometimes the best way
to think about a concept isn't the best (most flexible, simplest
to code, simplest to debug, ...) way to implement it.

Mahadevan Iyer wrote:
> 
> A problem well-stated is a problem half-solved.

Agreed - half.

Joe