Mention TE in draft-ietf-shim6-proto-01.txt?

[Brian E Carpenter <brc@zurich.ibm.com>]

I think we made an error in RFC 3582 by not mentioning transit
provider preferences explicitly in section 3.1.2, which only refers
to load sharing.

I suggest fixing that in the shim6 documents, and in the protocol
document I would suggest doing so principally in the first sentence
of the Introduction. Possible rewrite:

1.  Introduction

   The SHIM6 working group, and the MULTI6 WG that preceded it, is
   exploring a layer 3 shim approach for providing locator agility below
   the transport protocols, so that multihoming can be provided for IPv6
   with failover and load spreading properties [13] as well as transit
   provider preferences for traffic engineering, without assuming
   that a multihomed site will have a provider independent IPv6 address
   which is announced in the global IPv6 routing table.

I don't believe that any changes in basic shim6 are needed for this -
in fact I believe it's an RFC 3484 discussion to a large extent.

However, I have a related question about this:

6.1  Conceptual Data Structures

   The key conceptual data structure for the shim6 protocol is the host
   pair context.  This is a data structures which contains the following
   information:
   o  The peer ULID; ULID(peer)
   o  The local ULID; ULID(local)
   o  The list of peer locators, with their preferences; Ls(peer)

There's quite a lot in the draft about how preferences are communicated
and very little about where they come from. draft-ietf-shim6-arch-00.txt
doesn't help with this either. Somewhere, I think we need a list
of possible sources of these preferences, and dynamic or static TE policy
needs to be in that list.

Some discussion of traffic engineering in the architecture document
would also seem necessary.

    Brian