Subject: Re: [lisp] Adoption of draft-chiappa-lisp-architecture-01 and draft-chiappa-lisp-introduction-01

From: [email-masked] (Noel Chiappa)
Date: Wed, 5 Sep 2012 09:07:45 -0400 (EDT)

{Sorry I've been silent for a while - been taking a break.}

    > From: "Templin, Fred L" <[email-masked]>

    > I have long maintained that what LISP is calling "EID" is not really an
    > identifier

We've been around and around on this many times, and while the first few did I
think introduce some useful light, I think we're probably past the diminishing
returns at this point?

Believe it or not, this is a point on which I do have some sympathy: some
people may recognize one of my favourite quotations, which I have used in a
number of places:

  "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

Was 'EID' the best term to use? Perhaps not (although the difficulty in
introducing a new terms should not be ignored).

I am moved to mark the irony that while people continually complain over this
re-use of the term 'EID', I have yet to hear almost _anyone_ (other than me)
complain about the re-use of the term 'locator', which was clearly defined to
mean 'location sensitive name _which does not necessarily appear in every
packet_' (see Nimrod WG archives:

  http://mercury.lcs.mit.edu/~jnc/tech/nimrod/1993Sep-Dec.txt

where we found that we needed a new word as we found that people couldn't
free their minds from the assumption that an 'address' was something which
_had_ to appear in every packet - we had at that point yet to grasp that
their was an equal difficulty in people being sensitive to the fact that
'addresses' a la IPvN embodied both location _and_ identity - which is yet
_another_ example of terminology being warped).

So the term 'locator' is continually mis-used in the IETF (see, e.g. RFC-2373
"IPv6 Addressing Architecture", RFC-2956 "Overview of 1999 IAB Network Layer
Workshop"), but somehow nobody has a similar-sized problem with that. Why is
that?

Which is not to say, of course, that one wrong excuses another; multiple
definitions can indeed, as Petit observes, cause confusion.  But I am somewhat
peeved at what I see as disparate treatment in the two cases.

    > if the node has multiple independent (virtual) interfaces to which LISP
    > EIDs must be assigned, it is not possible to say that only one of them
    > is the "identity" of the endpoint

Suppose I had an architecture with 'true' EIDS. Suppose further that I
assigned a single node multiple 'true' EIDs. Which one is the 'identity'
of the node?

	Noel

---

From: "Templin, Fred L" <[email-masked]>
Date: Wed, 5 Sep 2012 08:47:57 -0700

Hi Noel,

> -----Original Message-----
> From: Noel Chiappa [mailto:[email-masked]]
> Sent: Wednesday, September 05, 2012 6:08 AM
> To: [email-masked]
> Cc: [email-masked]
> Subject: RE: [lisp] Adoption of draft-chiappa-lisp-architecture-01 and
> draft-chiappa-lisp-introduction-01
> 

I think a couple of examples such as the one I gave are useful
and can shed new light. See below for a second example.

> assigned a single node multiple 'true' EIDs. Which one is the 'identity'

As a second example, in the aviation industry today planes are being
rigged for three different and disjoint communications domains - Air
Traffic Control (ATC), Airline Operations Control (AOC) and Passenger
domain (some also consider Airline Administrative Control (AAC) as a
fourth domain). The FAA and Eurocontrol are deploying ATC as an
independent internetwork known as the Aeronautical Telecommunications
Network (ATN) which in its first instantiation will use the OSI TP4/CLNP
protocol stack instead of IP. One of the reasons given for this was that
using a totally different protocol suite would prevent internet hackers
from taking over an airplane if wires were accidentally crossed. So, the
ATN is a separate Internet from the airline network that supports AOC,
and the airline network is a separate Internet from the Passenger domain,
which connects to the public Internet. That's three different Internets
(one of which doesn't even use IP), and three different EIDs if something
like LISP is used. But, the plane is still known by only one identifier
(e.g., "Anonymous Airlines Flight 93").

Thanks - Fred
[email-masked]