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Versions: (draft-vanderstok-roll-admin-local-policy) 00 01 02 03 RFC 7732

roll                                                     P. van der Stok
Internet-Draft                                                Consultant
Intended status: Informational                                 R. Cragie
Expires: October 10, 2014                                      Gridmerge
                                                           April 8, 2014


       MPL forwarder policy for multicast with admin-local scope
                 draft-ietf-roll-admin-local-policy-00

Abstract

   The purpose of this document is to specify an automated policy for
   the routing of MPL multicast messages with admin-local scope in a
   border router.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
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   Internet-Drafts are draft documents valid for a maximum of six months
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   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on October 10, 2014.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   described in the Simplified BSD License.




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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology and Acronyms  . . . . . . . . . . . . . . . .   3
   2.  Network identifier  . . . . . . . . . . . . . . . . . . . . .   4
     2.1.  IEEE 802.15.4 . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  IEEE 802.11 . . . . . . . . . . . . . . . . . . . . . . .   4
     2.3.  ITU-T G.9959  . . . . . . . . . . . . . . . . . . . . . .   4
     2.4.  BLUETOOTH Low Energy  . . . . . . . . . . . . . . . . . .   5
   3.  MPL4 router . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  MPL interface parameters  . . . . . . . . . . . . . . . .   5
     3.2.  Determination of MPL zone . . . . . . . . . . . . . . . .   5
   4.  Admin-Local policy  . . . . . . . . . . . . . . . . . . . . .   6
     4.1.  Legal multicast messages  . . . . . . . . . . . . . . . .   7
     4.2.  Forwarding legal packets  . . . . . . . . . . . . . . . .   7
       4.2.1.  MPL message . . . . . . . . . . . . . . . . . . . . .   7
       4.2.2.  Multicast messages without MPL option . . . . . . . .   8
   5.  MPL domains and zones . . . . . . . . . . . . . . . . . . . .   8
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   9.  Change log  . . . . . . . . . . . . . . . . . . . . . . . . .   9
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     10.1.  Normative References . . . . . . . . . . . . . . . . . .   9
     10.2.  Informative References . . . . . . . . . . . . . . . . .  11
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   Multicast scopes are defined in [RFC4291].  The
   [I-D.ietf-6man-multicast-scopes] extends the scope definition with
   the text:

   "Interface-Local, Link-Local, and Realm-Local scope boundaries are
   automatically derived from physical connectivity or other, non-
   multicast related configuration.  Global scope has no boundary.  The
   boundaries of all other non-reserved scopes of Admin-Local or larger
   are administratively configured."

   The admin-local scope must therefore be administratively configured.
   This draft describes an automated policy for the MPL forwarding of
   multicast messages with admin-local scope within a border router.

   The realm-local multicast address is currently used by MPL to
   propagate the multicast message to all receivers and forwarders
   within a mesh network.  The multicast propagation is limited to a
   mesh network with a common layer-2.  For example, a LoWPAN is defined



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   by an IEEE 802.15.4 layer-2 mesh network, composed of all connected
   nodes sharing the same PAN ID [RFC4944].

   The network concept differs between mesh network technologies.  This
   document maps a general network identifier to the specific network
   identifier of existing mesh technologies.

   In current and projected deployments, there is a requirement to
   propagate a multicast message beyond the boundaries of the mesh
   network it originated in independent of the mesh technology.

   Consider the case where propagation over two mesh networks is
   required.  In one example, each mesh network has a border router and
   the two border routers are connected with an Ethernet link.  In
   another example each mesh network is connected to its own network
   interface connected to the same border router.  In both cases, an
   admin-local multicast message originating in one network needs to
   propagate into the other mesh network.  The boundary of the admin-
   local scope is administratively configured.

   This document describes an "MPL4 router" that forwards MPL messages
   with a multicast address with admin-local scope to all interfaces
   connected to links that connect to other MPL enabled interfaces.  The
   MPL4 router enables all its interfaces for MPL messages and allocates
   an additional variable MPL_BLOCKED that permits(forbids) the
   forwarding of MPL messages.

   It is expected that the network of an organization, building, or
   home, is connected to the Internet via the edge routers provided by
   an ISP.  The intention is that within the network of an organization,
   building, or home, MPL messages with multicast addresses of admin-
   local scope are freely forwarded but are never forwarded to edge
   routers which do not enable their interfaces for MPL messages.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

1.2.  Terminology and Acronyms

   This document uses terminology defined in
   [I-D.ietf-roll-trickle-mcast] and [I-D.ietf-6man-multicast-scopes].
   In addition, the following terms are used in this document:

   o  MPL4 message: an MPL DATA message with a destination multicast
      address of scope 4.



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   o  MPL4 router: automatically determines the zone in which MPL
      messages with admin-local scope can be propagated.

   o  MPL4 zone: a convex zone of interconnected interfaces over which
      MPL messages with admin-local scope propagate.  [RFC4007].

2.  Network identifier

   Links may have the concept of a channel, for example in wireless
   networks such a channel is associated with a communication frequency.
   Additionally, for some link technologies, several networks can
   coexist using the same channel.  For these link technologies, a
   network identifier exists.  The network identifier is determined by
   the link technology specification.  When no network identifier exists
   for a given link, the network identifier has the value "undefined".

2.1.  IEEE 802.15.4

   IPv6 over IEEE 802.15.4 is described in [RFC4944].  A LoWPAN is
   composed of the nodes connected by an IEEE 802.15.4 mesh sharing the
   same PAN ID.  The PAN ID identifies a network in the IEEE 802.15.4
   mesh.  Several networks with different PAN IDs can coexist on the
   same channel [IEEE802.15.4].  The PAN ID of an interface is defined
   when the interface is enabled.  The value of the network identifier
   of an IEEE 802.15.4 link is the value of the PAN ID.

2.2.  IEEE 802.11

   IP over IEEE 802.11 is described in [RFC5416].  The SSID identifies a
   network in the IEEE 802.11 link.  Several networks with different
   SSIDs can coexist on the same channel [IEEE802.11].  The SSID of an
   interface is defined when the interface is switched on.  The value of
   the network identifier of a IEEE 802.11 link is the value of the
   SSID.

2.3.  ITU-T G.9959

   IPv6 over ITU-T G.9959 is specified in [I-D.ietf-6lo-lowpanz].  The
   HomeID identifies a network of connected nodes [G.9959].  Several
   HomeIDs can coexist within communication range, but nodes adhering to
   a network with a given HomeID cannot communicate with nodes adhering
   to a network with a different HomeID.  The value of the network
   identifier of a G.9959 link is the value of the HomeID.








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2.4.  BLUETOOTH Low Energy

   IPv6 over BLUETOOTH Low Energy (BTLE) is specified in
   [I-D.ietf-6lo-btle].  The medium is specified in [btle].

   BTLE does not know the concept of multiple networks in one channel.
   The value of the network identifier of a BTLE link is "any".

3.  MPL4 router

   The concept of an MPL4 router serves to automatically determine the
   zone in which MPL messages with an scope 4 multicast address can
   propagate.  The MPL4 router periodically executes an algorithm that
   determines the presence of MPL interfaces on the links connected to
   its interfaces.  When no MPL interfaces are present on a given link,
   the corresponding MPL interface is signalled as not being part of the
   MPL zone.

3.1.  MPL interface parameters

   One parameter is associated with every MPL interface in the MPL4
   router, and two parameters are associated with the behaviour of the
   MPL4 router as a whole.

   o  MPL_BLOCKED: Boolean value that indicates whether the associated
      interface belongs to the MPL zone.

   o  MPL_CHECK_INT: integer that indicates the time interval between
      successive activations of the MPL4 router algorithm in seconds.

   o  MPL_TO: integer that indicates the interval in which MPL messages
      are expected in seconds.

3.2.  Determination of MPL zone

   All interfaces of the MPL4 router MUST be associated with following
   parameters coming from MPL protocol [I-D.ietf-roll-trickle-mcast]:
   PROACTIVE_FORWARDING, DATA_MESSAGE_IMIN, DATA_MESSAGE_IMAX,
   DATA_MESSAGE_K, DATA_MESSAGE_TIMER_EXPIRATIONS.  At start-up of the
   MPL4 router, the parameters associated with all interfaces are
   assigned the following values: PROACTIVE_FORWARDING = true,
   MPL_BLOCKED = false.  All interfaces MUST subscribe to the multicast
   addresses ALL_MPL_FORWARDERS scope 3 and scope 4.

   The MPL4 router executes the following algorithm for each interface:

   o  With a frequency determined by the value of MPL_CHECK_INT, the
      MPL4 router sends an MPL4 message on each interface with a header



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      that includes the MPL option and is sent to multicast address
      ALL_MPL_FORWARDERS with scope 4.

   o  When within an interval determined by the value of MPL_TO no MPL
      message is received, the value of MPL_BLOCKED is set to true.

   o  At reception of an MPL4 message with a multicast address with
      scope 4, the value of MPL_BLOCKED of the receiving interface is
      set to false.

   This protocol leads to a state where for each interface MPL_BLOCKED
   is set to false if and only if MPL enabled interfaces are connected
   to the link associated with the interface.  When an MPL message is
   submitted to an MPL-enabled interface -called A- in the MPL router,
   the TRICKLE algorithm is activated to send the MPL message.  The MPL4
   message with multicast address ALL_MPL_FORWARDERS scope 4 is accepted
   by every interface connected to the link that has subscribed to
   ALL_MPL_FORWARDERS with scope 4.  On acceptance of the MPL4 message
   by interface B, the MPL4 message is returned with Trickle over
   interface B. Consequently, the MPL4 message is received by the
   originating interface A, after which MPL_BLOCKED is set to false.

   When a new node is connected to the link, it can immediately send an
   MPL4 message, or can wait for the reception of an MPL4 message to
   announce its intention to be part of the MPL zone.

   TODO?: payload of message used for MPL parameter value negotiation.

4.  Admin-Local policy

   The section starts with specifying what multicast messages arriving
   at an interface are legal.  It continues with a description of
   forwarding legal admin-local multicast messages over other MPL
   interfaces.

   The policy for forwarding admin-local multicast messages
   automatically to a MPL interface is specified as function of the
   state of the MPL interface and the multicast message.  The state of
   the multicast message is determined by the presence of the MPL option
   and the destination multicast address.  The state of the MPL
   interface is determined by the subscribed multicast addresses, and
   the values of the PROACTIVE_FORWARDING parameter and the MPL_BLOCKED
   parameter of the MPL interface.








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4.1.  Legal multicast messages

   Multicast messages can be created within the node by an application
   or can arrive at an interface.

   A multicast message created at a source (MPL seed) is legal when it
   conforms to the properties described in section 9.1 of
   [I-D.ietf-roll-trickle-mcast].

   A multicast message received at a given interface is legal when:

   o  The message carries an MPL option (MPL message) and the incoming
      MPL interface is subscribed to the destination multicast address.

   o  The message does not carry an MPL option and the interface has
      expressed interest to receive messages with the specified
      multicast address via MLD [RFC3810] or via IGMP [RFC3376].  The
      message was sent on according to PIM-DM [RFC3973] or according to
      PIM-SM [RFC4601].

   Illegal multicast messages are discarded.

4.2.  Forwarding legal packets

   A legal multicast message received at a given interface is assigned
   the network identifier of the interface of the incoming link . A
   message that is created locally is assigned the network identifier
   "any".

   Two types of legal multicast messages are considered: (1) MPL
   messages, and (2) multicast messages which do not carry the MPL
   option.

4.2.1.  MPL message

   MPL messages are forwarded on MPL interfaces using the Trickle
   parameter values assigned to the MPL interface according to the
   following rules:

   o  Link-local (scope 2) MPL messages are not forwarded.

   o  Realm-local (scope 3) MPL messages are forwarded on all MPL
      interfaces that are subscribed to the same multicast address and
      have PROACTIVE-FORWARDING set to true, and the assigned network
      identifier of the multicast message is identical to the network
      identifier of the MPL interface, or the assigned network
      identifier of the multicast message is "any".




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   o  Admin-local (scope 4) MPL messages are forwarded on all MPL
      interfaces that are subscribed to the same multicast address, have
      PROACTIVE-FORWARDING set to true, and have MPL_BLOCKED set to
      false.

   o  MPL messages with a multicast scope of 5 or higher are out of
      scope for this specification.  (TODO: decapsulation of MPL
      option?)

4.2.2.  Multicast messages without MPL option

   Multicast messages without MPL option are forwarded on MPL interfaces
   according to the following rules:

   o  Link-local (scope 2) messages or realm-local (scope 3) multicast
      messages are not forwarded.

   o  Admin-local (scope 4) multicast messages are encapsulated with a
      header carrying the MPL option and are forwarded on al MPL
      interfaces that are subscribed to the multicast address, have
      PROACTIVE_FORWARDING set to true, and have MPL_BLOCKED set to
      false.

   o  Multicast messages with a multicast scope of 5 or higher follow
      the Multicast forwarding rules as specified by PIM [RFC3973],
      [RFC4601] according to group specifications enabled by MLD
      [RFC3810] or IGMP [RFC3376].

5.  MPL domains and zones

   An MPL domain is a scope zone in which MPL interfaces subscribe to
   the same MPL Domain Address [I-D.ietf-roll-trickle-mcast].  In
   accordance with [RFC4007] a zone boundary passes through a node.  For
   example, a small LLN node usually has one MPL mesh interface which is
   enabled to the ALL_MPL_FORWARDERS multicast address with a scope
   value of 3 (realm-local) [I-D.ietf-6man-multicast-scopes].  The node
   interface belongs to the zone and the corresponding zone boundary
   does not pass through this node.  In the border router with MPL
   interfaces enabled to the multicast address ALL_MPL_FORWARDERS with
   scope value 3, the zone includes usually this single interface and
   excludes all other interfaces.  A notable exception is provided by a
   node where MPL interfaces of the same technology share the same
   network identifier.  These interfaces belong to the same zone.

   In an MPL4 router, every MPL interface subscribes to the admin_local
   ALL_MPL_FORWARDERS multicast address next to the realm-local
   ALL_MPL_FORWARDERS address.




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   Every interface that belongs to an MPL domain that extends over
   border routers MUST subscribe the admin-local ALL_MPL_FORWARDERS
   address.

   The zone corresponding with the MPL multicast address
   ALL_MPL_FORWARDERS with scope 4 (Admin-local) applies to border
   routers with multiple interfaces, of which at least one interface is
   MPL enabled and is subscribed to multicast address ALL_MPL_FORWARDERS
   with scope 4.  In a border router, all MPL enabled interfaces which
   subscribe to the ALL_MPL_FORWARDERS address with scope 4 and for
   which MPL_BLOCKED is false belong to the same zone.

6.  Security Considerations

   Refer to the security considerations of
   [I-D.ietf-roll-trickle-mcast].

7.  IANA Considerations

   No considerations for IANA are formulated in this document.

8.  Acknowledgements

   This document reflects discussions and remarks from several
   individuals including (in alphabetical order): Esko Dijk, Matthew
   Gillmore, and Michael Richardson.

9.  Change log

   Changes from personal version to WG version.

   o  Aligned terminology with MPL terminology
      [I-D.ietf-roll-trickle-mcast]

   o  Text on MPL4 router included

10.  References

10.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3810]  Vida, R. and L. Costa, "Multicast Listener Discovery
              Version 2 (MLDv2) for IPv6", RFC 3810, June 2004.

   [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
              Architecture", RFC 4291, February 2006.



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   [RFC4944]  Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
              "Transmission of IPv6 Packets over IEEE 802.15.4
              Networks", RFC 4944, September 2007.

   [RFC3376]  Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A.
              Thyagarajan, "Internet Group Management Protocol, Version
              3", RFC 3376, October 2002.

   [RFC4007]  Deering, S., Haberman, B., Jinmei, T., Nordmark, E., and
              B. Zill, "IPv6 Scoped Address Architecture", RFC 4007,
              March 2005.

   [RFC5416]  Calhoun, P., Montemurro, M., and D. Stanley, "Control and
              Provisioning of Wireless Access Points (CAPWAP) Protocol
              Binding for IEEE 802.11", RFC 5416, March 2009.

   [I-D.ietf-6lo-lowpanz]
              Brandt, A. and J. Buron, "Transmission of IPv6 packets
              over ITU-T G.9959 Networks", draft-ietf-6lo-lowpanz-04
              (work in progress), March 2014.

   [I-D.ietf-roll-trickle-mcast]
              Hui, J. and R. Kelsey, "Multicast Protocol for Low power
              and Lossy Networks (MPL)", draft-ietf-roll-trickle-
              mcast-08 (work in progress), March 2014.

   [I-D.ietf-6man-multicast-scopes]
              Droms, R., "IPv6 Multicast Address Scopes", draft-ietf-
              6man-multicast-scopes-04 (work in progress), March 2014.

   [I-D.ietf-6lo-btle]
              Nieminen, J., Savolainen, T., Isomaki, M., Patil, B.,
              Shelby, Z., and C. Gomez, "Transmission of IPv6 Packets
              over BLUETOOTH Low Energy", draft-ietf-6lo-btle-00 (work
              in progress), November 2013.

   [IEEE802.15.4]
              "IEEE 802.15.4 - Standard for Local and metropolitan area
              networks -- Part 15.4: Low-Rate Wireless Personal Area
              Networks", <IEEE Standard 802.15.4>.

   [IEEE802.11]
              "IEEE 802.11 - Telecommunications and information exchange
              between systems Local and metropolitan area networks --
              Part 11: Wireless LAN Medium Access Control (MAC) and
              Physical Layer (PHY) Specifications", <IEEE Standard
              802.11>.




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   [G.9959]   "ITU-T G.9959 Short range narrow-band digital
              radiocommunication transceivers - PHY and MAC layer
              specifications", <ITU-T G.9959>.

   [btle]     "BLUETOOTH Specification Version 4.0", <BLUETOOTH low
              energy>.

10.2.  Informative References

   [RFC3973]  Adams, A., Nicholas, J., and W. Siadak, "Protocol
              Independent Multicast - Dense Mode (PIM-DM): Protocol
              Specification (Revised)", RFC 3973, January 2005.

   [RFC4601]  Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas,
              "Protocol Independent Multicast - Sparse Mode (PIM-SM):
              Protocol Specification (Revised)", RFC 4601, August 2006.

Authors' Addresses

   Peter van der Stok
   Consultant

   Email: consultancy@vanderstok.org


   Robert Cragie
   Gridmerge

   Email: robert.cragie@gridmerge.com






















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