Directional Airtime Metric Based on Packet Sequence Numbers for Optimized Link State Routing Version 2 (OLSRv2)
RFC 7779

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 00
• 01
• 02
• 03
• 04
• 05
• 06
• 07
• 08
• 09
• 10
• 11
• 12

Internet Engineering Task Force (IETF)                          H. Rogge
Request for Comments: 7779                               Fraunhofer FKIE
Category: Experimental                                       E. Baccelli
ISSN: 2070-1721                                                    INRIA
                                                              April 2016

    Directional Airtime Metric Based on Packet Sequence Numbers for
            Optimized Link State Routing Version 2 (OLSRv2)

Abstract

   This document specifies a Directional Airtime (DAT) link metric for
   usage in Optimized Link State Routing version 2 (OLSRv2).

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for examination, experimental implementation, and
   evaluation.

   This document defines an Experimental Protocol for the Internet
   community.  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).  Not
   all documents approved by the IESG are a candidate for any level of
   Internet Standard; see 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/rfc7779.

Copyright Notice

   Copyright (c) 2016 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
   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.

Rogge & Baccelli              Experimental                      [Page 1]
RFC 7779            Directional Airtime Metric OLSRv2         April 2016

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Applicability Statement . . . . . . . . . . . . . . . . . . .   4
   4.  Directional Airtime Metric Rationale  . . . . . . . . . . . .   5
   5.  Metric Functioning and Overview . . . . . . . . . . . . . . .   6
   6.  Protocol Constants  . . . . . . . . . . . . . . . . . . . . .   7
   7.  Protocol Parameters . . . . . . . . . . . . . . . . . . . . .   8
     7.1.  Recommended Values  . . . . . . . . . . . . . . . . . . .   8
   8.  Data Structures . . . . . . . . . . . . . . . . . . . . . . .   8
     8.1.  Initial Values  . . . . . . . . . . . . . . . . . . . . .   9
   9.  Packets and Messages  . . . . . . . . . . . . . . . . . . . .  10
     9.1.  Definitions . . . . . . . . . . . . . . . . . . . . . . .  10
     9.2.  Requirements for Using DAT Metric in OLSRv2
           Implementations . . . . . . . . . . . . . . . . . . . . .  10
     9.3.  Link-Loss Data Gathering  . . . . . . . . . . . . . . . .  11
     9.4.  HELLO Message Processing  . . . . . . . . . . . . . . . .  12
   10. Timer Event Handling  . . . . . . . . . . . . . . . . . . . .  12
     10.1.  Packet Timeout Processing  . . . . . . . . . . . . . . .  12
     10.2.  Metric Update  . . . . . . . . . . . . . . . . . . . . .  13
   11. Security Considerations . . . . . . . . . . . . . . . . . . .  14
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  14
     12.2.  Informative References . . . . . . . . . . . . . . . . .  15
   Appendix A.  Future Work  . . . . . . . . . . . . . . . . . . . .  17
   Appendix B.  OLSR.org Metric History  . . . . . . . . . . . . . .  17
   Appendix C.  Link-Speed Stabilization . . . . . . . . . . . . . .  18
   Appendix D.  Packet-Loss Hysteresis . . . . . . . . . . . . . . .  19
   Appendix E.  Example DAT Values . . . . . . . . . . . . . . . . .  19
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  20
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  21

1.  Introduction

   One of the major shortcomings of Optimized Link State Routing (OLSR)
   [RFC3626] is the lack of a granular link-cost metric between OLSR
   routers.  Operational experience with OLSR networks gathered since
   its publication has revealed that wireless networks links can have
   highly variable and heterogeneous properties.  This makes a hop-count
   metric insufficient for effective OLSR routing.

   Based on this experience, OLSRv2 [RFC7181] integrates the concept of
   link metrics directly into the core specification of the routing