Subject: RE: requirements draft revision

From: "Tony Hain" <[email-masked]>
Date: Mon, 2 Jul 2001 10:29:44 -0700

Tony Li wrote:
> | On the other hand, if you have a better definition, let's hear it.
>
>
> Randy sent you a fine definition that matches common accepted
> usage of the term.  Using that would be easier than trying to
> get the rest of the industry to change their definition.

My concern is that the term was defined and is assumed to be used in the
context of a tree structured interconnect environment, rather than the briar
patch of today's reality. After spending the last couple of days pounding on
rocks in the garden, let me try a couple of slightly modified definitions.

Enterprise: defines policy for a uniquely identifiable address prefix, and
expresses that policy to N providers.

Transit provider: T, to enterprise E accepts and propagates E's policy for
the uniquely identified prefix to the parts of the Internet within and
extending beyond T. The relationship between T & E may be direct or
indirect.

Getting back to Joe's example (w/small extension):

   A --- B --- C --- F
         |     |
         D     E
		\    /
           -G-

F defines policy for prefix 123.123.123/24; therefore is an enterprise.
C defines policy for prefix 123.123/16; therefore is an enterprise.
C propagates F's policy to B & E; therefore is a transit provider to F

B defines a policy for 222.222.222/24; therefore is an enterprise.
C propagates B's policy to E, and D & E propagate it to G; therefore C,D,&E
are transit providers to B

B accepts policies from C for the aggregate 123.123/16 & the enterprise
123.123.123/24, propagating those to A & D; therefore is a transit provider
to C and F.
** alternatively
B accepts policies from C for 123.123/16 & 123.123.123/24, but instead of
propagating those to A & D, defines a different policy for the aggregate
123/8; therefore is not a transit provider to C or F.

I think this fits what Joe has been saying, without implying directionality,
or customer relationship. The enterprise is defined in terms of its ability
to define policy for a prefix, rather than size, complexity, or number of
connections. It also does not require that the enterprise be able to
'ensure' an outcome, but allows expression of policy to any number of
providers. It also removes from discussion the entities that are multi-homed
but adapt to the current network state rather than express a policy to
affect it.

Tony