Subject: I-D Action: draft-ietf-trill-rbridge-multilevel-00.txt

From: [email-masked]
Date: Wed, 19 Aug 2015 11:10:00 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.
 This draft is a work item of the Transparent Interconnection of Lots of Links Working Group of the IETF.

        Title           : Alternatives for Multilevel TRILL (Transparent Interconnection of Lots of Links)
        Authors         : Radia Perlman
                          Donald Eastlake
                          Mingui Zhang
                          Anoop Ghanwani
                          Hongjun Zhai
	Filename        : draft-ietf-trill-rbridge-multilevel-00.txt
	Pages           : 30
	Date            : 2015-08-19

Abstract:
   Extending TRILL to multiple levels has challenges that are not
   addressed by the already-existing capability of IS-IS to have
   multiple levels.  One issue is with the handling of multi-destination
   packet distribution trees. Another issue is with TRILL switch
   nicknames.  There have been two proposed approaches.  One approach,
   which we refer to as the "unique nickname" approach, gives unique
   nicknames to all the TRILL switches in the multilevel campus, either
   by having the level-1/level-2 border TRILL switches advertise which
   nicknames are not available for assignment in the area, or by
   partitioning the 16-bit nickname into an "area" field and a "nickname
   inside the area" field.  The other approach, which we refer to as the
   "aggregated nickname" approach, involves hiding the nicknames within
   areas, allowing nicknames to be reused in different areas, by having
   the border TRILL switches rewrite the nickname fields when entering
   or leaving an area. Each of those approaches has advantages and
   disadvantages. This informational document suggests allowing a choice
   of approach in each area. This allows the simplicity of the unique
   nickname approach in installations in which there is no danger of
   running out of nicknames and allows the complexity of hiding the
   nicknames in an area to be phased into larger installations on a per-
   area basis.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-trill-rbridge-multilevel/

There's also a htmlized version available at:
https://tools.ietf.org/html/draft-ietf-trill-rbridge-multilevel-00

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