Subject: [lisp] I can find only one definition of "namespace"

From: Robin Whittle <[email-masked]>
Date: Sun, 22 Mar 2009 02:43:07 +1100

Apologies to anyone who breaks out in hives due to further mention of
*NAMESPACE*!

Hi Sam,

In "Re: LISP WG: Loc/ID separation - not separate namespaces"

   http://www.ietf.org/mail-archive/web/lisp/current/msg00299.html

you wrote, in part:

> You've presented one definition of namespace.  I strongly suspect
> that there are a lot of other definitions floating around and that
> the term was being used loosely.  I have not seen a lot of support
> for your strict definition of namespaces.

I have done an extensive literature search

   http://www.firstpr.com.au/ip/ivip/namespace/

and found several entirely compatible definitions of "namespace" in
the context of computer networking.  The most comprehensive one was:

   http://en.wikipedia.org/wiki/Namespace_(computer_science)

I found many instances of the term being used in RFCs and I-Ds which
were consistent with this definition, going back to the early 1990s.
 The most notable document making frequent references (44 at least)
to "namespace" in ways which entirely accord with the definitions I
found, was Noel Chiappa in an unfinished draft of an I-D, which is
nonetheless cited quite frequently:

   http://ana.lcs.mit.edu/~jnc/tech/endpoints.txt

I found a few instances of usage of the term which I think were loose
or incorrect, but that is normal and not suggestive of there being
another, different, genuine meaning in the author's mind.

I stand by my suggestion that it would be best to remove the term of
"namespace" from:

  http://tools.ietf.org/html/draft-farinacci-lisp-12
  http://tools.ietf.org/html/draft-lewis-lisp-interworking-02

and that the explicit statements about LISP creating separate
namespaces for EIDs and RLOCs in an IETF Journal article are
misleading as long as LISP is to be a practical solution to the
routing scaling problem.

In an earlier message I mentioned but did not link to a NANOG
presentation in which the "separate namespaces" claim was also made:

  http://www.nanog.org/mtg-0710/presentations/LISP-cons.pdf

That is old, not linked to from the LISP site and probably not read
much.  However statements about new namespaces are also made in two
2008 presentations which are linked from the LISP site:

  http://www.lisp4.net/docs/lisp-ripe-long.pdf

     Page 13 indicates that EIDs are a "new namespace".

  http://www.lisp4.net/docs/lisp-crc-aam-workshop.ppt

     Why Separate Location from ID?
     Level of Indirection allows us to:
         Keep either ID or Location fixed while changing the other
         Create separate namespaces which can have different
         allocation properties

My page listed above links to 13 mailing list messages since July
2007 in which I raised concerns about inferences or statements
regarding a practical core-edge separation system involving separate
namespaces for EIDs and RLOCs.

No alternative definition of "namespace" has yet been proposed.

  - Robin