Subject: Re: [arch-d] thoughts

From: [email-masked] (Noel Chiappa)
Date: Fri, 17 Nov 2006 20:53:17 -0500 (EST)

> From: David Conrad <[email-masked]>

    >> "end point" means a stack, a node, an interface, or something else ?

    > Interface (or perhaps more correctly, stack associated with an
    > interface).

Well, there's a source of potential confusion, because to a lot of people,
"endpoint" means about what "stack" seemingly does - i.e. an entity involved
in end-end communication (e.g. the "thing" at one end of a reliable transport
connection, which manages the state associated with that connection).

This is especially true after my draft on "endpoint names" some years back
(http://www.chiappa.net/~jnc/tech/endpoints.txt -yes, yes, I know I need to
get it out as an RFC :-), which discussed adding a separate namespace for
them, at some length.

Time to roll out my favourite terminology quotation again:

  "I am far from thinking that nomenclature is a remedy for every defect in
  art or science: still I cannot but feel that confusion of terms generally
  springs from, and always leads to, confusion of ideas."

       -- John Louis Petit, "Architectural Studies in France", 1854

Maybe we should add that to the "welcome to the list" message? :-)

I'd also like to point out that "stack associated with an interface" is
really just "[end-end identity] associated with [a network location]" - which
is what got us in trouble in the first place. I view the application of a
single name to anything that mixes those two spheres with a very jaundiced
eye.

	Noel

_______________________________________________
Architecture-discuss mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/architecture-discuss

---

From: John Day <[email-masked]>
Date: Fri, 17 Nov 2006 21:14:02 -0500

Noel is correct.  Terminology doesn't solve everything but my 
favorite quote is  "A problem well stated is a problem half solved." 
Charles Kettering

>     > Interface (or perhaps more correctly, stack associated with an

One can not assume a 1:1 relation between interfaces and stacks. 
That is unless you are in 802.

Take care,
John

---

From: Scott W Brim <[email-masked]>
Date: Sun, 19 Nov 2006 07:57:38 -0500

I'm just catching up but I wanted to toss this in to start with ...

> Maybe we should add that to the "welcome to the list" message? :-)

    By this it appears how necessary it is for any man that aspires to
    true knowledge, to examine the definitions of former authors; and
    either to correct them, where they are negligently set down, or to
    make them himself.  For the errors of definitions multiply
    themselves according as the reckoning proceeds, and lead men into
    absurdities, which at least they see, but cannot avoid, without
    reckoning anew from the beginning.
    
					  Hobbes, Leviathan (1651)

---

From: John Day <[email-masked]>
Date: Sun, 19 Nov 2006 08:06:59 -0500

So with all of these good minds saying the same thing, why do we 
continually insist on not doing it? Even belittling those who do.

Rhetorical question, of course.  ;-)

---

From: David Conrad <[email-masked]>
Date: Sun, 19 Nov 2006 12:06:24 -0800

Noel,

> connection, which manages the state associated with that connection).

Right.  From my perspective, an interface is a piece of (potentially  
virtual) hardware.  A stack associated with an interface turns that  
interface into an "end point" (at each layer in the stack).

> is what got us in trouble in the first place.

I don't really see it this way.  I view a stack as a set of protocol  
implementations, each one of which has a set of 'handles' that allow  
for communication upwards and downwards in the stack.  Where we got  
into trouble is that because one 'handle' was used to name multiple  
points in the stack, we overloaded multiple semantics onto those  
handles.

But maybe that's saying the same thing.

Rgds,
-drc

---

From: David Conrad <[email-masked]>
Date: Sun, 19 Nov 2006 12:08:15 -0800

John,

> One can not assume a 1:1 relation between interfaces and stacks.

Right.  That's why I said "instantiations".  I'm aware that the  
relationship can be 1 to many, many to one, etc.

Rgds,
-drc