Routing Metrics Used for Path Calculation in Low-Power and Lossy Networks
RFC 6551

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Internet Engineering Task Force (IETF)                  JP. Vasseur, Ed.
Request for Comments: 6551                                 Cisco Systems
Category: Standards Track                                    M. Kim, Ed.
ISSN: 2070-1721                           Corporate Technology Group, KT
                                                               K. Pister
                                                           Dust Networks
                                                               N. Dejean
                                                              Elster SAS
                                                              D. Barthel
                                                   France Telecom Orange
                                                              March 2012

              Routing Metrics Used for Path Calculation in
                      Low-Power and Lossy Networks

Abstract

   Low-Power and Lossy Networks (LLNs) have unique characteristics
   compared with traditional wired and ad hoc networks that require the
   specification of new routing metrics and constraints.  By contrast,
   with typical Interior Gateway Protocol (IGP) routing metrics using
   hop counts or link metrics, this document specifies a set of link and
   node routing metrics and constraints suitable to LLNs to be used by
   the Routing Protocol for Low-Power and Lossy Networks (RPL).

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6551.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of

Vasseur, et al.              Standards Track                    [Page 1]
RFC 6551          Routing for Path Calculation in LLNs        March 2012

   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................3
      1.1. Requirements Language ......................................6
   2. Object Formats ..................................................7
      2.1. DAG Metric Container Format ................................7
      2.2. Use of Multiple DAG Metric Containers .....................10
      2.3. Metric Usage ..............................................10
   3. Node Metric/Constraint Objects .................................11
      3.1. Node State and Attribute Object ...........................11
      3.2. Node Energy Object ........................................12
      3.3. Hop Count Object ..........................................16
   4. Link Metric/Constraint Objects .................................17
      4.1. Throughput ................................................17
      4.2. Latency ...................................................18
      4.3. Link Reliability ..........................................19
           4.3.1. The Link Quality Level Reliability Metric ..........19
           4.3.2. The ETX Reliability Object .........................21
      4.4. Link Color Object .........................................22
           4.4.1. Link Color Object Description ......................22
           4.4.2. Mode of Operation ..................................24
   5. Computation of Dynamic Metrics and Attributes ..................24
   6. IANA Considerations ............................................25
      6.1. Routing Metric/Constraint Type ............................25
      6.2. Routing Metric/Constraint TLVs ............................25
      6.3. Routing Metric/Constraint Common Header Flag Field ........26
      6.4. Routing Metric/Constraint Common Header A Field ...........26
      6.5. NSA Object Flags Field ....................................26
      6.6. Hop-Count Object Flags Field ..............................27
      6.7. Node Type Field ...........................................27
   7. Security Considerations ........................................27
   8. Acknowledgements ...............................................28