[ih] Protocol layering

[Phill Gross]

> cites two outputs of SC16..
> 
> I have no idea how you'd acquire them, but presumably they sit in a file
> cabinet somewhere...

Craig, Thanks for the references.  Getting copies is definitely the problem.
Anyone in this group have a dusty filing cabinet?

> I did a quick look through back network management stuff but didn't
> find any obvious pointers to a telco standard document.

I've queried a number of experienced telecom folks and the consensus appears
to be 1) the 3-plane model was not original intended to be applied to
layered protocols, although it's been adopted later for that use, 2) they
are not able to cite sources for standard definitions of how to apply it to
layered protocols, but more interestingly, 3) they couldn't point to the
original standard that defined it for telecom(!).  

I've found a number of documents (eg, BISDN) that use some flavor of the
3-plane model, but most seemed derived and often modified (eg, adding extra
planes).  I'm still tracing references.  If I find the headwaters, I'll
report back.

Perhaps the 3-plane model is like that other widespread concept that defies
clear definition, and like Potter Stewart, we just know it when we see it.
: )

Phill