Subject: RE: additional requirement: cooperation

From: "Michel Py" <[email-masked]>
Date: Mon, 12 Nov 2001 09:59:23 -0800

>> A multihoming strategy MAY require cooperation between a site
>> and its transit providers, but MUST NOT require cooperation
>> directly between the transit providers.

More on this:
The term "directly connected" I used before is obviously a poor choice
of words, especially for the 6bone.

The word "neighbor" is not appropriate either, because it has some
strong BGP connotations: an "ebgp-multihop" BGP neighbor could be
completely unrelated to one's router.

I welcome other phrasing and someone to check my bad English, this is
what I coined:

"direct neighbor" : As related to two transit providers, direct
neighbors are BGP peers that can communicate without crossing any AS
that is not owned by either transit provider.

The cooperation additional requirement could then be:

"A multihoming strategy MAY require cooperation between a site
and its transit providers, but MUST NOT require cooperation
directly between the transit providers except for direct neighbors".

---

From: Joe Abley <[email-masked]>
Date: Mon, 12 Nov 2001 13:10:13 -0500

> that is not owned by either transit provider.

How about:

  Two sites are "direct neighbours" if they are able to exchange
  traffic betwen their sites directly, without IP datagrams being
  processed by a router located at some third site.

That avoids the routing connotations, but accommodates traffic
carried over tunnels (since the encapsulated packets' IP datagrams
are unmolested by the routers involved in providing tunnel transport).

I can relax my spelling of "neighbour" if necessary :)

> directly between the transit providers except for direct neighbors".

Joe