Tuning the Behavior of the Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) for Routers in Mobile and Wireless Networks
RFC 6636

Internet Engineering Task Force (IETF)                         H. Asaeda
Request for Comments: 6636                               Keio University
Category: Informational                                           H. Liu
ISSN: 2070-1721                                                    Q. Wu
                                                                  Huawei
                                                                May 2012

  Tuning the Behavior of the Internet Group Management Protocol (IGMP)
                 and Multicast Listener Discovery (MLD)
              for Routers in Mobile and Wireless Networks

Abstract

   The Internet Group Management Protocol (IGMP) and Multicast Listener
   Discovery (MLD) are the protocols used by hosts and multicast routers
   to exchange their IP multicast group memberships with each other.
   This document describes ways to achieve IGMPv3 and MLDv2 protocol
   optimization for mobility and aims to become a guideline for the
   tuning of IGMPv3/MLDv2 Queries, timers, and counter values.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   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/rfc6636.

Asaeda, et al.                Informational                     [Page 1]
RFC 6636           Tuning the Behavior of IGMP and MLD          May 2012

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
   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 ....................................................2
   2. Terminology .....................................................3
   3. Explicit Tracking of Membership Status ..........................3
   4. Tuning IGMP/MLD Timers and Values ...............................4
      4.1. Tuning the IGMP/MLD General Query Interval .................4
      4.2. Tuning the IGMP/MLD Query Response Interval ................5
      4.3. Tuning the Last Member Query Timer (LMQT) and Last
           Listener Query Timer (LLQT) ................................6
      4.4. Tuning the Startup Query Interval ..........................7
      4.5. Tuning the Robustness Variable .............................7
      4.6. Tuning Scenarios for Various Mobile IP Networks ............7
   5. Destination Address of a Specific Query .........................8
   6. Interoperability ................................................9
   7. Security Considerations .........................................9
   8. Acknowledgements ................................................9
   9. References .....................................................10
      9.1. Normative References ......................................10
      9.2. Informative References ....................................10
   Appendix A. Unicasting a General Query ............................11

1.  Introduction

   The Internet Group Management Protocol (IGMP) [1] for IPv4 and the
   Multicast Listener Discovery (MLD) [2] protocol for IPv6 are the
   standard protocols for hosts to initiate joining or leaving of
   multicast sessions.  These protocols must also be supported by
   multicast routers or IGMP/MLD proxies [5] that maintain multicast
   membership information on their downstream interfaces.  Conceptually,
   IGMP and MLD work on both wireless and mobile networks.  However,
   wireless access technologies operate on a shared medium or a point-
   to-point link with limited spectrum and bandwidth.  In many wireless

Asaeda, et al.                Informational                     [Page 2]
RFC 6636           Tuning the Behavior of IGMP and MLD          May 2012