Path Aware Networking: A Bestiary of Roads Not Taken

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PANRG                                                    S. Dawkins, Ed.
Internet-Draft                                       Huawei Technologies
Intended status: Informational                            March 19, 2018
Expires: September 20, 2018

          Path Aware Networking: A Bestiary of Roads Not Taken


   At the first meeting of the proposed Path Aware Networking Research
   Group, Oliver Bonaventure led a discussion of our mostly-unsuccessful
   attempts to exploit Path Awareness to achieve a variety of goals,
   over the past decade.  At the end of that discussion, the research
   group agreed to catalog and analyze these ideas, to extract lessons
   for network researchers.

   This document contains that catalog and analysis.

Status of This Memo

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   This Internet-Draft will expire on September 20, 2018.

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   include Simplified BSD License text as described in Section 4.e of
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1.  Introduction

   At IETF 99, the proposed Path Aware Networking Research Group [PANRG]
   held its first meeting [PANRG-99], and the first presentation in that
   session was "A Decade of Path Awareness" [PATH-Decade].  At the end
   of this discussion, two things were abundantly clear.

   o  The Internet community has accumulated considerable experience
      with many Path Awareness ideas over a long period of time, and

   o  Although some Path Awareness ideas have been successfully deployed
      (for example, Differentiated Services, or DiffServ [RFC2475]),
      most of these ideas haven't seen widespread adoption.  The reasons
      for this non-adoption are many and varied.

   The meta-lessons from this experience are

   o  Path Aware Networking is more Research than Engineering, so
      establishing an IRTF Research Group for Path Aware Networking is
      the right thing to do [RFC7418], and

   o  Cataloging and analyzing our experience to learn the reasons for
      non-adoption is a great first step for the proposed Research

   This document contains that catalog and analysis.

1.1.  About this Document

   This document is not intended to include every idea about Path Aware
   Networking that we can find.  Instead, we include enough ideas to
   provide background for new lessons to guide researchers in their
   work, in order to add those lessons to Section 2.

   There is no shame to having your idea included in this document.  We
   were trying to engineer something that was research.  The document
   editor started with a subsection on his own idea.  The only shame is
   not learning from experience, and not sharing that experience with
   other networking researchers and engineers.

   This document is being built collaboratively.  To contribute your
   experience, please send a Github pull request to

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   Discussion of contributed experiences should take place on the PANRG
   mailing list.

2.  Summary of Lessons Learned

   This section summarizes the Lessons Learned from the contributed
   sections in Section 4.

   o  The benefit of Path Awareness has to be great enough to overcome
      entropy for already-deployed devices.  The colloquial American
      English expression, "If it ain't broke, don't fix it" is in full
      flower on today's Internet.

   o  If intermediate devices along the path can't be trusted, it's
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