[ih] Why did location/identity separation not happen? (Was: Internet without entrenched factions?)

[Noel Chiappa]

    > From: Ole Troan

    > Back to history. IPv6 should have had identifier/locator split from the
    > start. I wasn't there, but I understood it was close with Mike O'Dell's
    > 8+8 and GSE proposals? Anyone who can shed more light on what happened
    > and why that path was not chosen?

I wasn't paying very close attention by then, so I don't know for sure why
8+8/GSE didn't get support, but I would guess that it was for many of the
same reasons that earlier attempts to add location/identity separation to the
internetworking architecture (i.e. the 'basic, high-level picture', used in
the Internet) failed to catch on.

Those, I believe, I am very well qualified to muse about, since I'm pretty
certain (if my memory is failling me in this, which might well be possible, I
hope someone will correct me) was the first person in the Internet technical
community (which was, at the time, pretty well entirely encompassed in the
IETF/IRTF groups) to suggest, and push, adding separation of location and
identity to that architecture.

(The basic idea, of course, originated with Jerry Saltzer, in his paper "On
the Naming and Binding of Network Destinations". As soon as I saw it, I
realized the crucial flaw in the then-current internet architecture which it
pointed out, and took steps to get it re-published as an RFC - RFC 1498 - to
make it easily accessible to the Internet technical community; it had
originally been published in a somewhat obscure journal. I can't remember if
Jerry provided me with a machine-readable copy of the text, for that; I have
a vague memory that that had been lost, and I had to re-type it all from a
hard copy.

Also, the version of the idea that I pushed had one major change from Jerry's
original: he had proposed recognizing four classes of entities - "services,
nodes, attachment points, and routes [i.e. paths]". Dave Oran suggested to me
(in a conversation at a meeting in LA, if memory serves - the memory is still
fairly vivid) that physical hosts were the wrong thing, it needed to be
something more abstract, and I instantly saw the correctness of his point.

I drew on Clark's original "fate-sharing" thinking, used in the early TCP
work, to replace 'node/host' with 'endpoint' - defined as "a fatesharing
region" ("a boundary drawn around a set of state and/or computations such
that it lives or dies as a unit"), which is "one participant of an end-end
communication" ("the fundamental agent [in] end-end communication"). Excerpts
here are from:

  http://chiappa.net/~jnc/tech/endpoints.txt

"Endpoints and Endpoint Names: A Proposed Enhancement to the Internet
Architecture". )


Anyway: what, from my perception, were the reason(s) that separation of
location and identity failed to catch on in the Internet technical community?
It can, I believe, be put, whimsically but pithily, as 'there were too many
programmers in that technical community'. (This may irritate people; I don't
care, I'll be gone before too long. I don't say it to irritate _anyone_, but
because I believe it is accurate.)

Whhaaatttt?

Let me make an analogy. The basic plan for the layout of Washington, D.C.
(the 'architecture', in the sense I have used it above) was drawn up by
Pierre Charles L'Enfant. Now, imagine that the basic plan for Washington had
instead been drawn up by a committee of the brick-layers who had built the
original buildings in Washington. Does anyone think they would have come up
with as timeless a layout? The brick-layers, good people though they
undoubtdedly were. were almost certainly just not able to operate at the
level of abstraction on which L'Enfant did.

To less whimsically explain what I said at the start , I think the vast
majority of the members of the IETF technical community could only see the
value in a significantly new direction if they had seen it fully constituted,
in a working system. 

(In this they were not without predecessors: when Paul Baran came up with the
basic idea of a packet network, I gather that when people from the Bell
system (in the US) looked at his scheme, they largely did not think it would
work. The irony of that is, well, ironic; given that their enormous,
important, circuit-switched network has, today, been largely been replaced by
a packet-switching network.

I have very vague memories that a similar sort of thing happened in the early
days of internet work - that most people from Bell did not think it was the
correct direction. Even Bell's Datakit system - reportedly a predecessor to
ATM - retained circuits.)

I think that it's sort of related to Clarke's Third Law ("When a
distinguished but elderly scientist states that something is possible, he is
almost certainly right. When he states that something is impossible, he is
very probably wrong.") Most people (in general, not just elderly scientists)
cannot discard their knowledge in one approach, to strike out in a whole new
direction.

To put it another way: there's a reason that IPv6 looks a lot like IPv4, with
a few more bits.


I could go on at some length, but I expect I'd just be boring people; I can
add more if anyone is intereted.

    Noel