Subject: [rbridge] TRILL Prob statement submitted

From: touch at ISI.EDU (Joe Touch)
Date: Thu, 17 Nov 2005 16:06:09 -0800

Hi, all,

I had a chance to update the problem statement to avoid all references
to rbridges; the result, including corrected title and filename, was
submitted today, and represents the 00 version from which to start
discussion. It has been posted on the rbridge website, and should appear
in the draft directories shortly.

The similarly updated rbridge architecture doc should be posted
tomorrow, FYI.

Joe

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TRILL WG                                                 J. Touch (ed.)
Internet Draft                                                  USC/ISI
Expires: May 2006                                     November 17, 2005

           Transparent Interconnection of Lots of Links (TRILL):
                    Problem and Applicability Statement
                       draft-touch-trill-prob-00.txt

...

Abstract

   Current Ethernet (802.1) link layers use custom routing protocols
   that have a number of challenges. The routing protocols need to
   strictly avoid loops, even temporary loops during route propagation,
   because of the lack of header loop detection support. Routing tends
   not to take full advantage of alternate paths, or even non-
   overlapping pairwise paths (in the case of spanning trees). The
   convergence of these routing protocols and stability under link
   changes and failures is also of concern. This document addresses
   these concerns and suggests that they are related to the need to be
   able to apply network layer routing (e.g., link state or distance
   vector) protocols at the link layer. This document assumes that
   solutions would not address issues of scalability beyond that of
   existing bridged (802.1D) links, but that a solution would be
   backward compatible with 802.1D, including hubs, bridges, and their
   existing plug-and-play capabilities.

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From: gibanez at it.uc3m.es (Guillermo Ibáñez)
Date: Fri, 18 Nov 2005 10:33:26 +0100

Please forgive me if I discuss already agreed statements, but I would 
like to understand the reasons to exclude the scalability from the 
objectives. A minimum target should be stated for number of hosts. 
Taking into account that Ethernet networks are expanding in size, and 
the number of devices increases this is one of the main requirements for 
the near future. Besides this, it is a contradiction to look to replace 
routers inside campus networks and in practice we use them again because 
the replacement will not scale enough midterm. It seems  a bit 
shorsighted approach.  
Guillermo

Joe Touch wrote:

>------------------------------------------------------------------------
>
>_______________________________________________
>rbridge mailing list
>rbridge at postel.org
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>  
>

-- 
Guillermo Ib??ez
Departamento de Ingenier?a Telem?tica
Universidad Carlos III de Madrid
1.1.B.11 Colmenarejo 91-6241393
4.1.F.13 Legan?s 91-6248794

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From: touch at ISI.EDU (Joe Touch)
Date: Fri, 18 Nov 2005 11:49:14 -0800

Hi, all,

The rbridge architecture doc has been posted to the Internet drafts.
The only change was the reference to the P&AS doc, and that this document
is currently considered the product of a few authors rather than an
editor (that decision can be revised if accepted as a WG doc).

Joe

- ---

TRILL WG                                                       J. Touch
Internet Draft                                                  USC/ISI
Expires: May 2006                                            R. Perlman
                                                                    Sun
                                                      November 18, 2005

             The Architecture of an RBridge Solution to TRILL
                   draft-touch-trill-rbridge-arch-00.txt

...
Abstract

   RBridges are link layer (L2) devices that use routing protocols as a
   control plane. They combine the link layer ability to allow hosts to
   reattach without renumbering with network layer routing benefits.
   RBridges use existing link state routing to provide higher internal
   cross-section bandwidth, faster convergence under reconfiguration,
   and more robustness to link interruption than an equivalent set of
   conventional bridges using existing spanning tree forwarding. They
   are intended to apply to similar L2 network sizes as conventional
   bridges and are intended to be backward compatible with those bridges
   as both ingress/egress and transit. They also attempt to retain as
   much 'plug and play' as is already available in existing bridges.
   This document proposes the RBridge system as a solution to the TRILL
   problem. It also defines the RBridge architecture, presents its
   terminology, and describes its basic components and desired behavior.
   A separate document specifies the protocols and mechanisms that
   satisfy the architecture presented herein.