[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-clausen-manet-olsrv2) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 RFC 7181

Mobile Ad hoc Networking (MANET)                              T. Clausen
Internet-Draft                          LIX, Ecole Polytechnique, France
Expires: December 28, 2006                                   C. Dearlove
                                         BAE Systems Advanced Technology
                                                                  Centre
                                                              P. Jacquet
                                                 Project Hipercom, INRIA
                                                  The OLSRv2 Design Team
                                                     MANET Working Group
                                                           June 26, 2006


          The Optimized Link-State Routing Protocol version 2
                       draft-ietf-manet-olsrv2-02

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on December 28, 2006.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This document describes version 2 of the Optimized Link State Routing
   (OLSRv2) protocol for mobile ad hoc networks.  The protocol embodies



Clausen, et al.         Expires December 28, 2006               [Page 1]

Internet-Draft                   OLSRv2                        June 2006


   an optimization of the classical link state algorithm tailored to the
   requirements of a mobile wireless LAN.

   The key optimization of OLSRv2 is that of multipoint relays,
   providing an efficient mechanism for network-wide broadcast of link-
   state information (i.e. reducing the cost of performing a network-
   wide link-state broadcast).  A secondary optimization is that OLSRv2
   employs partial link-state information: each node maintains
   information about all destinations, but only a subset of links.  This
   allows that only select nodes diffuse link-state advertisements (i.e.
   reduces the number of network-wide link-state broadcasts) and that
   these advertisements contain only a subset of links (i.e. reduces the
   size of each network-wide link-state broadcast).  The partial link-
   state information thus obtained still allows each OLSRv2 node to at
   all times maintain optimal (in terms of number of hops) routes to all
   destinations in the network.

   OLSRv2 imposes minimum requirements to the network by not requiring
   sequenced or reliable transmission of control traffic.  Furthermore,
   the only interaction between OLSRv2 and the IP stack is routing table
   management.

   OLSRv2 is particularly suitable for large and dense networks as the
   technique of MPRs works well in this context.



























Clausen, et al.         Expires December 28, 2006               [Page 2]

Internet-Draft                   OLSRv2                        June 2006


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  5
     1.1.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  6
     1.2.  Applicability Statement  . . . . . . . . . . . . . . . . .  6
   2.  Protocol Overview and Functioning  . . . . . . . . . . . . . .  8
     2.1.  Protocol Extensibility . . . . . . . . . . . . . . . . . . 10
   3.  Processing and Forwarding Repositories . . . . . . . . . . . . 11
     3.1.  Received Set . . . . . . . . . . . . . . . . . . . . . . . 11
     3.2.  Fragment Set . . . . . . . . . . . . . . . . . . . . . . . 11
     3.3.  Processed Set  . . . . . . . . . . . . . . . . . . . . . . 12
     3.4.  Forwarded Set  . . . . . . . . . . . . . . . . . . . . . . 12
     3.5.  Relay Set  . . . . . . . . . . . . . . . . . . . . . . . . 12
   4.  Packet Processing and Message Forwarding . . . . . . . . . . . 14
     4.1.  Actions when Receiving an OLSRv2 Packet  . . . . . . . . . 14
     4.2.  Actions when Receiving an OLSRv2 Message . . . . . . . . . 14
     4.3.  Message Considered for Processing  . . . . . . . . . . . . 15
     4.4.  Message Considered for Forwarding  . . . . . . . . . . . . 17
   5.  Information Repositories . . . . . . . . . . . . . . . . . . . 20
     5.1.  Neighborhood Information Base  . . . . . . . . . . . . . . 20
       5.1.1.  Link Set . . . . . . . . . . . . . . . . . . . . . . . 20
       5.1.2.  MPR Set  . . . . . . . . . . . . . . . . . . . . . . . 21
       5.1.3.  MPR Selector Set . . . . . . . . . . . . . . . . . . . 21
     5.2.  Topology Information Base  . . . . . . . . . . . . . . . . 21
       5.2.1.  Advertised Neighbor Set  . . . . . . . . . . . . . . . 21
       5.2.2.  ANSN History Set . . . . . . . . . . . . . . . . . . . 22
       5.2.3.  Topology Set . . . . . . . . . . . . . . . . . . . . . 22
       5.2.4.  Attached Network Set . . . . . . . . . . . . . . . . . 23
       5.2.5.  Routing Set  . . . . . . . . . . . . . . . . . . . . . 23
   6.  OLSRv2 Control Message Structures  . . . . . . . . . . . . . . 24
     6.1.  General OLSRv2 Message TLVs  . . . . . . . . . . . . . . . 24
       6.1.1.  VALIDITY_TIME TLV  . . . . . . . . . . . . . . . . . . 24
     6.2.  HELLO Messages . . . . . . . . . . . . . . . . . . . . . . 25
       6.2.1.  HELLO Message OLSRv2 Message TLVs  . . . . . . . . . . 26
       6.2.2.  HELLO Message OLSRv2 Address Block TLVs  . . . . . . . 26
     6.3.  TC Messages  . . . . . . . . . . . . . . . . . . . . . . . 27
     6.4.  TC Message: OLSRv2 Address Block TLVs  . . . . . . . . . . 27
   7.  HELLO Message Generation . . . . . . . . . . . . . . . . . . . 29
     7.1.  HELLO Message: Transmission  . . . . . . . . . . . . . . . 29
   8.  HELLO Message Processing . . . . . . . . . . . . . . . . . . . 30
     8.1.  Populating the MPR Selector Set  . . . . . . . . . . . . . 30
     8.2.  Symmetric Neighborhood and 2-Hop Neighborhood Changes  . . 31
   9.  TC Message Generation  . . . . . . . . . . . . . . . . . . . . 32
     9.1.  TC Message: Transmission . . . . . . . . . . . . . . . . . 33
   10. TC Message Processing  . . . . . . . . . . . . . . . . . . . . 34
     10.1. Single TC Message Processing . . . . . . . . . . . . . . . 34
       10.1.1. Populating the ANSN History Set  . . . . . . . . . . . 35
       10.1.2. Populating the Topology Set  . . . . . . . . . . . . . 35



Clausen, et al.         Expires December 28, 2006               [Page 3]

Internet-Draft                   OLSRv2                        June 2006


       10.1.3. Populating the Attached Network Set  . . . . . . . . . 36
     10.2. Completed TC Message Processing  . . . . . . . . . . . . . 37
       10.2.1. Purging the Topology Set . . . . . . . . . . . . . . . 37
       10.2.2. Purging the Attached Network Set . . . . . . . . . . . 37
   11. Populating the MPR Set . . . . . . . . . . . . . . . . . . . . 38
   12. Populating Derived Sets  . . . . . . . . . . . . . . . . . . . 39
     12.1. Populating the Relay Set . . . . . . . . . . . . . . . . . 39
     12.2. Populating the Advertised Neighbor Set . . . . . . . . . . 39
   13. Routing Table Calculation  . . . . . . . . . . . . . . . . . . 40
   14. Proposed Values for Constants  . . . . . . . . . . . . . . . . 44
     14.1. Neighborhood Discovery Constants . . . . . . . . . . . . . 44
     14.2. Message Intervals  . . . . . . . . . . . . . . . . . . . . 44
     14.3. Holding Times  . . . . . . . . . . . . . . . . . . . . . . 44
     14.4. Willingness  . . . . . . . . . . . . . . . . . . . . . . . 44
   15. Sequence Numbers . . . . . . . . . . . . . . . . . . . . . . . 45
   16. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 46
     16.1. Multicast Addresses  . . . . . . . . . . . . . . . . . . . 46
     16.2. Message Types  . . . . . . . . . . . . . . . . . . . . . . 46
     16.3. TLV Types  . . . . . . . . . . . . . . . . . . . . . . . . 46
   17. References . . . . . . . . . . . . . . . . . . . . . . . . . . 48
     17.1. Normative References . . . . . . . . . . . . . . . . . . . 48
     17.2. Informative References . . . . . . . . . . . . . . . . . . 48
   Appendix A.   Example Heuristic for Calculating MPRs . . . . . . . 49
   Appendix B.   Heuristics for Generating Control Traffic  . . . . . 52
   Appendix C.   Protocol and Port Number . . . . . . . . . . . . . . 53
   Appendix D.   Packet and Message Layout  . . . . . . . . . . . . . 54
   Appendix D.1. OLSRv2 Packet Format . . . . . . . . . . . . . . . . 54
   Appendix E.   Node Configuration . . . . . . . . . . . . . . . . . 59
   Appendix F.   Jitter . . . . . . . . . . . . . . . . . . . . . . . 60
   Appendix G.   Security Considerations  . . . . . . . . . . . . . . 63
   Appendix G.1. Confidentiality  . . . . . . . . . . . . . . . . . . 63
   Appendix G.2. Integrity  . . . . . . . . . . . . . . . . . . . . . 63
   Appendix G.3. Interaction with External Routing Domains  . . . . . 64
   Appendix G.4. Node Identity  . . . . . . . . . . . . . . . . . . . 65
   Appendix H.   Flow and Congestion Control  . . . . . . . . . . . . 66
   Appendix I.   Contributors . . . . . . . . . . . . . . . . . . . . 67
   Appendix J.   Acknowledgements . . . . . . . . . . . . . . . . . . 68
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 69
   Intellectual Property and Copyright Statements . . . . . . . . . . 70












Clausen, et al.         Expires December 28, 2006               [Page 4]

Internet-Draft                   OLSRv2                        June 2006


1.  Introduction

   The Optimized Link State Routing protocol version 2 (OLSRv2) is an
   update to OLSRv1 as published in RFC3626 [1].  Compared to RFC3626,
   OLSRv2 retains the same basic mechanisms and algorithms, while
   providing an even more flexible signaling framework and some
   simplification of the messages being exchanged.  Also, OLSRv2 takes
   care to accommodate both IPv4 and IPv6 addresses in a compact
   fashion.

   OLSRv2 is developed for mobile ad hoc networks.  It operates as a
   table driven, proactive protocol, i.e. it exchanges topology
   information with other nodes of the network regularly.  Each node
   selects a set of its neighbor nodes as "MultiPoint Relays" (MPRs).
   Only nodes that are selected as such MPRs are then responsible for
   forwarding control traffic intended for diffusion into the entire
   network.  MPRs provide an efficient mechanism for flooding control
   traffic by reducing the number of transmissions required.

   Nodes selected as MPRs also have a special responsibility when
   declaring link state information in the network.  Indeed, the only
   requirement for OLSRv2 to provide shortest path routes to all
   destinations is that MPR nodes declare link-state information for
   their MPR selectors.  Additional available link-state information may
   be utilized, e.g. for redundancy.

   Nodes which have been selected as multipoint relays by some neighbor
   node(s) announce this information periodically in their control
   messages.  Thereby a node announces to the network that it has
   reachability to the nodes which have selected it as an MPR.  Thus, as
   well as being used to facilitate efficient flooding, MPRs are also
   used for route calculation from any given node to any destination in
   the network.

   A node selects MPRs from among its one hop neighbors with
   "symmetric", i.e. bi-directional, linkages.  Therefore, selecting
   routes through MPRs automatically avoids the problems associated with
   data packet transfer over uni-directional links (such as the problem
   of not getting link-layer acknowledgments for data packets at each
   hop, for link-layers employing this technique for unicast traffic).

   OLSRv2 is developed to work independently from other protocols.
   Likewise, OLSRv2 makes no assumptions about the underlying link-
   layer.  However, OLSRv2 may use link-layer information and
   notifications when available and applicable.

   OLSRv2, as OLSRv1, inherits the concept of forwarding and relaying
   from HIPERLAN (a MAC layer protocol) which is standardized by ETSI



Clausen, et al.         Expires December 28, 2006               [Page 5]

Internet-Draft                   OLSRv2                        June 2006


   [6].

1.1.  Terminology

   The keywords "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 [2].

   MANET specific terminology is to be interpreted as described in [3]
   and [4].

   Additionally, this document uses the following terminology:

   node - A MANET router which implements the Optimized Link State
      Routing protocol version 2 as specified in this document.

   OLSRv2 interface - A MANET interface, running OLSRv2.

   symmetric strict 2-hop neighbor - A symmetric 2-hop neighbor which is
      not a symmetric 1-hop neighbor and is not a 2-hop neighbor only
      through a symmetric 1-hop neighbor with willingness WILL_NEVER.
      (If node Z is a symmetric 2-hop neighbor of node X then there is a
      node Y such that node Z is a symmetric 1-hop neighbor of node Y
      and node Y is a symmetric 1-hop neighbor of node X. If node Z is a
      symmetric strict 2-hop neighbor of node X then there is such a
      node Y with willingness which is not WILL_NEVER.)

   symmetric strict 2-hop neighborhood - The set of the symmetric strict
      2-hop neighbors of node X.

   multipoint relay (MPR) - A node which is selected by its symmetric
      1-hop neighbor, node X, to "re-transmit" all the broadcast
      messages that it receives from node X, provided that the message
      is not a duplicate, and that the hop limit field of the message is
      greater than one.

   MPR selector - A node which has selected its symmetric 1-hop
      neighbor, node X, as one of its MPRs is an MPR selector of node X.

1.2.  Applicability Statement

   OLSRv2 is a proactive routing protocol for mobile ad hoc networks
   (MANETs) [7], [8].  It is well suited to large and dense networks of
   mobile nodes, as the optimization achieved using the MPRs works well
   in this context.  The larger and more dense a network, the more
   optimization can be achieved as compared to the classic link state
   algorithm.  OLSRv2 uses hop-by-hop routing, i.e. each node uses its
   local information to route packets.



Clausen, et al.         Expires December 28, 2006               [Page 6]

Internet-Draft                   OLSRv2                        June 2006


   As OLSRv2 continuously maintains routes to all destinations in the
   network, the protocol is beneficial for traffic patterns where the
   traffic is random and sporadic between a large subset of nodes, and
   where the [source, destination] pairs are changing over time: no
   additional control traffic need be generated in this situation since
   routes are maintained for all known destinations at all times.  Also,
   since routes are maintained continuously, traffic is subject to no
   delays due to buffering/route-discovery.  This continued route
   maintenance may be done using periodic message exchange, as detailed
   in this specification, or triggered by external events if available.

   OLSRv2 supports nodes which have multiple interfaces which
   participate in the MANET.  OLSRv2, additionally, supports nodes which
   have non-MANET interfaces which can serve as (if configured to do so)
   gateways towards other networks.

   The message exchange format, contained in previous versions of this
   specification, has been factored out to an independent specification
   [3], which is used for carrying OLSRv2 control signals.  OLSRv2 is
   thereby able to allow for extensions via "external" and "internal"
   extensibility.  External extensibility implies that a protocol
   extension may specify and exchange new message types, formatted
   according to [3], which can be forwarded and delivered correctly.
   Internal extensibility implies that a protocol extension may define
   additional attributes to be carried embedded in the standard OLSRv2
   control messages detailed in this specification, using the TLV
   mechanism specified in [3], while OLSRv2 control messages with
   additional attributes can still be correctly understood by all OLSRv2
   nodes.

   The OLSRv2 neighborhood discovery protocol using HELLO messages has
   likewise been factored out to an independent specification [4].  This
   neighborhood discovery protocol serves to ensure that each OLSRv2
   node has available continuously updated information repositories
   describing the node's 1-hop and 2-hop neighbors. [4] uses the message
   format specified in [3], and hence is extensible as described above.















Clausen, et al.         Expires December 28, 2006               [Page 7]

Internet-Draft                   OLSRv2                        June 2006


2.  Protocol Overview and Functioning

   OLSRv2 is a proactive routing protocol for mobile ad hoc networks.
   The protocol inherits the stability of a link state algorithm and has
   the advantage of having routes immediately available when needed due
   to its proactive nature.  OLSRv2 is an optimization over the
   classical link state protocol, tailored for mobile ad hoc networks.
   The main tailoring and optimizations of OLSRv2 are:

   o  periodic, unacknowledged transmission of all control messages;

   o  optimized flooding for global link-state information diffusion;

   o  partial topology maintenance - each node knows only a subset of
      the links in the network, sufficient for a minimum hop route to
      all destinations.

   Using the message exchange format [3] and the neighborhood discovery
   protocol [4], OLSRv2 also contains the following main components:

   o  a TLV, to be included within the HELLO messages of [4], allowing a
      node to signal MPR selection;

   o  an optimized flooding mechanism for global information exchange,
      denoted "MPR flooding";

   o  a specification of global signaling, denoted TC (Topology Control)
      messages.  TC messages in OLSRv2 serve to:

      *  inject link-state information into the entire network;

      *  inject addresses of hosts and networks for which they may serve
         as a gateway into the entire network.

      TC messages are emitted periodically, thereby allowing nodes to
      continuously track global changes in the network.

   The use of [4] allows a node to continuously track changes to its
   local topology up to two hops away.  This allows a node to make
   provisions for ensuring optimized flooding, denoted "MPR flooding",
   as well as injection of link-state information into the network.
   This is done through the notion of MultiPoint Relays (MPRs).

   The idea of MPRs is to minimize the overhead of flooding messages in
   the network by reducing redundant retransmissions of messages in the
   same region.  Each node in the network selects an MPR Set, a set of
   nodes in its symmetric 1-hop neighborhood which may retransmit its
   messages.  The 1-hop neighbors of a node which are not in its MPR set



Clausen, et al.         Expires December 28, 2006               [Page 8]

Internet-Draft                   OLSRv2                        June 2006


   receive and process broadcast messages, but do not retransmit
   broadcast messages received from that node.  The MPR Set of a node X
   may be any subset of its symmetric 1-hop neighborhood such that every
   node in its symmetric strict 2-hop neighborhood has a symmetric link
   to a node in the MPR Set of node X. The MPR Set of a node may thus be
   said to "cover" the node's symmetric strict 2-hop neighborhood.  The
   smaller a MPR Set, the fewer times messages are forwarded and the
   less resulting control traffic overhead. [8] gives an analysis and
   example of MPR selection algorithms.  Note that as long as the
   condition above is satisfied, any algorithm selecting MPR Sets is
   acceptable in terms of implementation interoperability.

   Each node maintains information about the set of symmetric 1-hop
   neighbors that have selected it as MPR.  This set is called the MPR
   Selector Set of the node.  A node obtains this information from an
   MPR TLV which is inserted into the HELLO message exchange of [4].

   Each node also maintains a Relay Set, which is the set of nodes for
   which a node is to relay broadcast traffic.  The Relay Set is derived
   from the MPR Selector Set in that the Relay Set MUST contain all the
   nodes in the MPR Selector set and MAY contain additional nodes.

   Using the MPR flooding mechanism, link-state information can be
   injected into the network.  For this purpose, a node maintains an
   Advertised Neighbor Set which MUST contain all the nodes in the MPR
   selector set and MAY contain additional nodes.  If the Advertised
   Neighbor Set of a node is non-empty, it is reported in TC messages
   generated by that node.  If the Advertised Neighbor Set is empty, TC
   messages are not generated by that node, unless needed for gateway
   reporting, or for a short period to accelerate the removal of
   unwanted links.

   OLSRv2 is designed to work in a completely distributed manner and
   does not depend on any central entity.  The protocol does not require
   reliable transmission of control messages: each node sends control
   messages periodically, and can therefore sustain a reasonable loss of
   some such messages.  Such losses may occur frequently in radio
   networks due to collisions or other transmission problems.

   OLSRv2 does not require sequenced delivery of messages.  Each control
   message contains a sequence number which is incremented for each
   message.  Thus the recipient of a control message can, if required,
   easily identify which information is more recent - even if messages
   have been re-ordered while in transmission.

   OLSRv2 does not require any changes to the format of IP packets, any
   existing IP stack can be used as is: OLSRv2 only interacts with
   routing table management.  OLSR sends its control messages using UDP.



Clausen, et al.         Expires December 28, 2006               [Page 9]

Internet-Draft                   OLSRv2                        June 2006


2.1.  Protocol Extensibility

   OLSRv2 uses the neighborhood discovery mechanism of [4], and
   specifies additionally one message type, TC, and a number of TLVs.
   All messages exchanged by [4] and by OLSRv2 use and comply with the
   extensible message exchange format of [3], thus OLSR provides both
   "external" extensibility (addition of new message types as in OLSRv1
   [1]) and "internal" extensibility (addition of information to
   existing messages through TLVs) as described in [3].

   Those nodes which do not recognize a new message type ("external
   extensibility") will ignore this message type for processing, but
   will correctly forward the message, if specified in the message
   header.  Those nodes which do not recognize a newly defined TLV type
   ignore the added TLV, but process (if the message type is recognized)
   the message correctly, as well as forwards the message, if specified
   in the message header.


































Clausen, et al.         Expires December 28, 2006              [Page 10]

Internet-Draft                   OLSRv2                        June 2006


3.  Processing and Forwarding Repositories

   The following data structures are employed in order to ensure that a
   message is processed at most once and is forwarded at most once per
   interface of a node, and that fragmented content is treated
   correctly.

3.1.  Received Set

   Each node maintains, for each OLSRv2 interface, a set of signatures
   of messages, which have been received over that interface, in the
   form of "Received Tuples":

      (RX_type, RX_orig_addr, RX_seq_number, RX_time)

   where:

   RX_type is the received message type, or zero if the received message
      sequence number is not type-specific;

   RX_orig_addr is the originator address of the received message;

   RX_seq_number is the message sequence number of the received message;

   RX_time specifies the time at which this Received Tuple expires and
      *MUST* be removed.

   In a node, this is denoted the "Received Set" for that interface.

3.2.   Fragment Set

   Each node stores messages containing fragmented content until all
   fragments are received and the message processing can be completed,
   in the form of "Fragment Tuples":

      (FG_message, FG_time)

   where:

   FG_message is the message containing fragmented content;

   FG_time specifies the time at which this Fragment Tuple expires and
      MUST be removed.

   In a node, this is denoted the "Fragment Set".






Clausen, et al.         Expires December 28, 2006              [Page 11]

Internet-Draft                   OLSRv2                        June 2006


3.3.  Processed Set

   Each node maintains a set of signatures of messages which have been
   processed by the node, in the form of "Processed Tuples":

      (P_type, P_orig_addr, P_seq_number, P_time)

   where:

   P_type is the processed message type, or zero if the processed
      message sequence number is not type-specific;

   P_orig_addr is the originator address of the processed message;

   P_seq_number is the message sequence number of the processed message;

   P_time specifies the time at which this Processed Tuple expires and
      *MUST* be removed.

   In a node, this is denoted the "Processed Set".

3.4.  Forwarded Set

   Each node maintains a set of signatures of messages which have been
   retransmitted/forwarded by the node, in the form of "Forwarded
   Tuples":

      (FW_type, FW_orig_addr, FW_seq_number, FW_time)

   where:

   FW_type is the forwarded message type, or zero if the forwarded
      message sequence number is not type-specific;

   FW_orig_addr is the originator address of the forwarded message;

   FW_seq_number is the message sequence number of the forwarded
      message;

   FW_time specifies the time at which this Forward Tuple expires and
      *MUST* be removed.

   In a node, this is denoted the "Forwarded Set".

3.5.  Relay Set

   Each node maintains a set of neighbor interface addresses for which
   it is to relay flooded messages, in the form of "Relay Tuples":



Clausen, et al.         Expires December 28, 2006              [Page 12]

Internet-Draft                   OLSRv2                        June 2006


      (RY_iface_addr)

   where:

   RY_iface_addr is the address of a neighbor interface for which the
      node SHOULD relay flooded messages.  This MUST include a prefix
      length.

   In a node, this is denoted the "Relay Set".










































Clausen, et al.         Expires December 28, 2006              [Page 13]

Internet-Draft                   OLSRv2                        June 2006


4.  Packet Processing and Message Forwarding

   On receiving a basic packet, as defined in [3], a node examines each
   of the message headers.  If the message type is known to the node,
   the message is processed locally according to the specifications for
   that message type.  The message is also independently evaluated for
   forwarding.

4.1.  Actions when Receiving an OLSRv2 Packet

   On receiving a packet, a node MUST perform the following tasks:

   1.  The packet may be fully parsed on reception, or the packet and
       its messages may be parsed only as required.  (It is possible to
       parse the packet header, or determine its absence, without
       parsing any messages.  It is possible to divide the packet into
       messages without even fully parsing their headers.  It is
       possible to determine whether a message is to be forwarded, and
       to forward it, without parsing its body.  It is possible to
       determine whether a message is to be processed without parsing
       its body.  It is possible to determine if that processing may be
       delayed because the message is a fragment by inspecting the first
       few octets of the message body without fully parsing it.)

   2.  If parsing fails at any point the relevant entity (packet or
       message) MUST be silently discarded, other parts of the packet
       (up to the whole packet) MAY be silently discarded;

   3.  Otherwise if the packet header is present and it contains a
       packet TLV block, then each TLV in it is processed according to
       its type;

   4.  Otherwise each message in the packet, if any, is treated
       according to Section 4.2.

4.2.  Actions when Receiving an OLSRv2 Message

   A node MUST perform the following tasks for each received OLSRv2
   message:

   1.  If the received OLSRv2 message header cannot be correctly parsed
       according to the specification in [3], or if the node recognizes
       from the originator address of the message that the message is
       one which the receiving node itself originated, then the message
       MUST be silently discarded;

   2.  Otherwise:




Clausen, et al.         Expires December 28, 2006              [Page 14]

Internet-Draft                   OLSRv2                        June 2006


       1.  If the received message is of a known type then the message
           is considered for processing according to Section 4.3, AND;

       2.  If for the received message (<hop-limit> + <hop-count>) > 1,
           then the message is considered for forwarding according to
           Section 4.4.

4.3.  Message Considered for Processing

   If a message (the "current message") is considered for processing,
   the following tasks MUST be performed:

   1.  If an entry exists in the Processed Set where:

       *  P_type == the message type of the current message, or 0 if the
          typedep bit in the message semantics octet (in the message
          header) of the current message is cleared ('0'), AND;

       *  P_orig_addr == the originator address of the current message,
          AND;

       *  P_seq_number == the message sequence number of the current
          message.

       then the current message MUST NOT be processed.

   2.  Otherwise:

       1.  Create an entry in the Processed Set with:

           +  P_type = the message type of the current message, or 0 if
              the typedep bit in the message semantics octet (in the
              message header) of the current message is cleared ('0');

           +  P_orig_addr = originator address of the current message;

           +  P_seq_number = sequence number of the current message;

           +  P_time = current time + P_HOLD_TIME.

       2.  If the current message does not contain a valid message TLV
           with Type == FRAGMENTATION (or if it does and the indicated
           number of fragments is one) then process the message fully
           according to its type.

       3.  Otherwise:





Clausen, et al.         Expires December 28, 2006              [Page 15]

Internet-Draft                   OLSRv2                        June 2006


           1.  If the current message does not contain a valid message
               TLV with Type == CONT_SEQ_NUM then the current message
               MUST be silently discarded;

           2.  Otherwise if the current message is "partially or wholly
               self-contained", as indicated by the notselfcont bit in
               the Value field of the TLV with Type == FRAGMENTATION
               being cleared ('0'), then process the current message as
               far as possible according to its type;

           3.  If the Fragment Set includes any Fragment Tuples with:

               -  either the typedepseq bit in the Value field of the
                  TLV with Type == FRAGMENTATION in the current message
                  is cleared ('0') OR message type of FG_message ==
                  message type of current message, AND;

               -  originator address of FG_message == originator address
                  of current message, AND;

               -  content sequence number (the Value field of the
                  message TLV with Type == CONT_SEQ_NUM) of FG_message
                  == content sequence number of current message; AND

               -  either fragment number (from the Value field of the
                  TLV with Type == FRAGMENTATION) in FG_message ==
                  fragment number of current message OR number of
                  fragments (from the Value field of the TLV with Type
                  == FRAGMENTATION) of FG_message != number of fragments
                  of current message;

               then remove these Fragment Tuples from the Fragment Set;

           4.  If the Fragment Set includes Fragment Tuples containing
               all the remaining fragments of the same overall message
               as the current message, i.e. if the number of Fragment
               Tuples such that:

               -  either the typedepseq bit in the Value field of the
                  TLV with Type == FRAGMENTATION in the current message
                  is cleared ('0') OR message type of FG_message ==
                  message type of current message, AND;

               -  originator address of FG_message == originator address
                  of current message, AND;

               -  content sequence number (the Value field of the
                  message TLV with Type == CONT_SEQ_NUM) of FG_message



Clausen, et al.         Expires December 28, 2006              [Page 16]

Internet-Draft                   OLSRv2                        June 2006


                  == content sequence number of current message

               is equal to (number of fragments of current message, less
               one) then all of these Fragment Tuples are removed from
               the Fragment Set and their messages processed according
               to their type (taking account of any previous processing
               of any which are partially or wholly self-contained);

           5.  Otherwise, a Fragment Tuple is added to the Fragment Set
               with

               -  FG_message = current message;

               -  FG_time = current time + FG_HOLD_TIME;

               possibly replacing a previously received instance of the
               same fragment.

4.4.  Message Considered for Forwarding

   If a message is considered for forwarding, and it is either of a
   message type defined in this document or of an unknown message type,
   then it MUST use the following algorithm.  A message type not defined
   in this document MAY specify the use of this, or another algorithm.
   (Such an other algorithm MAY use the Received Set for the receiving
   interface, it SHOULD use the Forwarded Set similarly to the following
   algorithm.)

   If a message is considered for forwarding according to this
   algorithm, the following tasks MUST be performed:

   1.  If the sending interface (as indicated by the source interface of
       the IP datagram containing the message) does not match (taking
       into account any address prefix of) any N_neighbor_iface_addr in
       any Symmetric Neighbor Tuple, then the message MUST be silently
       discarded.

   2.  Otherwise:

       1.  If an entry exists in the Received Set for the receiving
           interface, where:

           +  RX_type == the message type, or 0 if the typedep bit in
              the message semantics octet (in the message header) is
              cleared ('0'), AND;

           +  RX_orig_addr == the originator address of the received
              message, AND;



Clausen, et al.         Expires December 28, 2006              [Page 17]

Internet-Draft                   OLSRv2                        June 2006


           +  RX_seq_number == the sequence number of the received
              message.

           then the message MUST be silently discarded.

       2.  Otherwise:

           1.  Create an entry in the Received Set for the receiving
               interface with:

               -  RX_type = the message type, or 0 if the typedep bit in
                  the message semantics octet (in the message header) is
                  cleared ('0');

               -  RX_orig_addr = originator address of the message;

               -  RX_seq_number = sequence number of the message;

               -  RX_time = current time + RX_HOLD_TIME.

           2.  If an entry exists in the Forwarded Set where:

               -  FW_type == the message type, or 0 if the typedep bit
                  in the message semantics octet (in the message header)
                  is cleared ('0');

               -  FW_orig_addr == the originator address of the received
                  message, AND;

               -  FW_seq_number == the sequence number of the received
                  message.

               then the message MUST be silently discarded.

           3.  Otherwise if a Relay Tuple exists whose RY_iface_addr
               matches (taking into account any address prefix) the
               sending interface (as indicated by the source interface
               of the IP datagram containing the message):

               1.  Create an entry in the Forwarded Set with:

                   o  FW_type = the message type, or 0 if the typedep
                      bit in the message semantics octet (in the message
                      header) is cleared ('0');

                   o  FW_orig_addr = originator address of the message;





Clausen, et al.         Expires December 28, 2006              [Page 18]

Internet-Draft                   OLSRv2                        June 2006


                   o  FW_seq_number = sequence number of the message;

                   o  FW_time = current time + FW_HOLD_TIME.

               2.  The message header is modified as follows:

                   o  Decrement <hop-limit> in the message header by 1;

                   o  Increment <hop-count> in the message header by 1;

               3.  Transmit the message on all OLSRv2 interfaces of the
                   node.

   Messages are retransmitted in the format specified by [3] with the
   ALL-MANET-NEIGHBORS address (see Section 16.1) as destination IP
   address.



































Clausen, et al.         Expires December 28, 2006              [Page 19]

Internet-Draft                   OLSRv2                        June 2006


5.  Information Repositories

   The purpose of OLSRv2 is to determine the Routing Set, which may be
   used to update IP's Routing Table, providing "next hop" routing
   information for IP datagrams.  In order to accomplish this, OLSRv2
   uses a number of protocol sets: the Neighborhood Information Base,
   provided by [4], is in OLSRv2 augmented by information allowing MPR
   selection and signaling.  Additionally, OLSRv2 specifies a Topology
   Information Base, which describes the information used for and
   acquired through TC message exchange - in other words: the topology
   base represents the network topology graph as seen from each node.

   Addresses (other than originator addresses) recorded in the
   Neighborhood Information Base and the Topology Information Base MUST
   all be recorded with prefix lengths, in order to allow comparison
   with addresses received in HELLO and TC messages.  For the Topology
   Information Base this applies to A_neighbor_iface_addr,
   T_dest_iface_addr, T_last_iface_addr, AN_net_addr, AN_gw_iface_addr,
   R_dest_addr, R_dest_addr, R_next_iface_addr and R_local_iface_addr,
   but not AH_orig_addr.  For the Neighborhood Information Base see [4].

5.1.  Neighborhood Information Base

   The neighborhood information base stores information about links
   between local interfaces and interfaces on adjacent nodes.  In
   addition to the sets described in [4], OLSRv2 adds an element to each
   Link Tuple to allow a node to record the willingness of a 1-hop
   neighbor node to be selected as an MPR.  Also, OLSRv2 adds an MPR Set
   and an MPR Selector Set to the Neighborhood Information Base.  The
   MPR Set is used by a node to record which of its symmetric 1-hop
   neighbors are selected as MPRs, and the MPR Selector Set is used by a
   node to record which of its symmetric 1-hop neighbors have selected
   it as MPR.  Thus the MPR Set is used, in addition to what is
   specified in [4], when generating HELLO messages, and the MPR
   Selector Set is populated, in addition to what is specified in [4]
   when processing HELLO messages.

5.1.1.  Link Set

   The Link Tuples, specified in [4] are augmented by an element,
   L_willingness:

   L_willingness is the node's willingness to be selected as an MPR;

   The remaining elements of the Link Tuples are as specified in [4].






Clausen, et al.         Expires December 28, 2006              [Page 20]

Internet-Draft                   OLSRv2                        June 2006


5.1.2.  MPR Set

   A node maintains a set of all of the OLSRv2 interface addresses with
   which the node has a symmetric link and which are of 1-hop symmetric
   neighbors which the node has selected as MPRs.  This is denoted the
   "MPR Set".

5.1.3.  MPR Selector Set

   A node maintains a set of "MPR Selector Tuples" containing all of the
   OLSRv2 interface addresses with which the node has a symmetric link
   and which are of 1-hop symmetric neighbors which have selected the
   node as an MPR.

       (MS_neighbor_iface_addr, MS_time)

   MS_neighbor_iface_addr specifies an OLSRv2 interface address with
      which the node has a symmetric link and which is of a 1-hop
      symmetric neighbor which has selected the node as an MPR;

   MS_time specifies the time at which this MPR Selector Tuple expires
      and *MUST* be removed.

   In a node, the set of MPR Selector Tuples is denoted the "MPR
   Selector Set".

5.2.  Topology Information Base

   The Topology Information Base stores information, required for the
   generation and processing of TC messages.  The Advertised Neighbor
   Set contains OLSRv2 interface addresses of symmetric 1-hop neighbors
   which are to be reported in TC messages.  The Topology Set and
   Attached Network Set both record information received through TC
   messages.  Thus the Advertised Neighbor Set is used for generating TC
   messages, while the Topology Set and Attached Network Set are
   populated when processing TC messages.

   Additionally, a Routing Set is maintained, derived from the
   information recorded in the Neighborhood Information Base, Topology
   Set and Attached Network Set.

5.2.1.  Advertised Neighbor Set

   A node maintains a set of OLSRv2 interface addresses of symmetric
   1-hop neighbors, which are to be advertised through TC messages:

       (A_neighbor_iface_addr)




Clausen, et al.         Expires December 28, 2006              [Page 21]

Internet-Draft                   OLSRv2                        June 2006


   For this set, an Advertised Neighbor Set Sequence Number (ANSN) is
   maintained.  Each time the Advertised Neighbor Set is updated, the
   ANSN MUST be incremented.  The ANSN MUST also be incremented if any
   locally advertised attached networks are added or removed.

5.2.2.  ANSN History Set

   A node records a set of "ANSN History Tuples", recording information
   about the freshness of the topology information received from each
   other node:

       (AH_orig_addr, AH_seq_number, AH_time)

   AH_orig_addr is the originator address of a received TC message;

   AH_seq_number is the highest ANSN in any TC message received which
      originated from AH_orig_addr;

   AH_time is the time at which this ANSN History Tuple expires and
      *MUST* be removed.

   In a node, the set of ANSN History Tuples is denoted the "ANSN
   History Set".

5.2.3.  Topology Set

   Each node in the network maintains topology information about the
   network in the form of "Topology Tuples":

       (T_dest_iface_addr, T_last_iface_addr, T_seq_number, T_time)

   T_dest_iface_addr is an OLSRv2 interface address of a destination
      node, which may be reached in one hop from the node with the
      OLSRv2 interface address T_last_iface_addr;

   T_last_iface_addr is, conversely, an OLSRv2 interface address of a
      node which is the last hop on a path towards the node with OLSRv2
      interface address T_dest_iface_addr.  Typically, the node with
      OLSRv2 interface address T_last_iface_addr is a MPR of the node
      with OLSRv2 interface address T_dest_iface_addr;

   T_seq_number is the highest received ANSN associated with the
      information contained in this Topology Tuple;

   T_time specifies the time at which this Topology Tuple expires and
      *MUST* be removed.

   In a node, the set of Topology Tuples is denoted the "Topology Set".



Clausen, et al.         Expires December 28, 2006              [Page 22]

Internet-Draft                   OLSRv2                        June 2006


5.2.4.  Attached Network Set

   Each node in the network maintains information about attached
   networks in the form of "Attached Network Tuples":

       (AN_net_addr, AN_gw_iface_addr, AN_seq_number, AN_time)

   AN_net_addr is the network address (including prefix length) of an
      attached network, which may be reached via the node with the
      OLSRv2 interface address AN_gw_iface_addr;

   AN_gw_iface_addr is the address of an OLSRv2 interface of a node
      which can act as gateway to the network identified by AN_net_addr;

   AN_seq_number is the highest received ANSN associated with the
      information contained in this Attached Network Tuple;

   AN_time specifies the time at which this Attached Network Tuple
      expires and *MUST* be removed.

   In a node, the set of Attached Network Tuples is denoted the
   "Attached Network Set".

5.2.5.  Routing Set

   A node records a set of "Routing Tuples" describing the selected path
   to each destination in the network for which a route is known:

      (R_dest_addr, R_next_iface_addr, R_dist, R_local_iface_addr)

   R_dest_addr is the address of the destination, either the address of
      an OLSRv2 interface of a destination node, or the network address
      of an attached network;

   R_next_iface_addr is the OLSRv2 interface address of the "next hop"
      on the selected path to the destination;

   R_dist is the number of hops on the selected path to the destination;

   R_local_iface_addr is the address of the local interface over which a
      packet MUST be sent to reach the destination.

   In a node, the set of Routing Tuples is denoted the "Routing Set".








Clausen, et al.         Expires December 28, 2006              [Page 23]

Internet-Draft                   OLSRv2                        June 2006


6.  OLSRv2 Control Message Structures

   Nodes using OLSRv2 exchange information through messages.  One or
   more messages sent by a node at the same time are combined into a
   packet.  These messages may have originated at the sending node, or
   have originated at another node and forwarded by the sending node.
   Messages with different originators may be combined in the same
   packet.

   The packet and message format used by OLSRv2 is defined in [3].
   However this specification contains some options which are not used
   by OLSRv2.  In particular (using the syntactical elements defined in
   the packet format specification):

   o  All OLSRv2 packets, not limited to those defined in this document,
      include a <packet-header>.

   o  All OLSRv2 packets, not limited to those defined in this document,
      have the pseqnum bit of <packet-semantics> cleared ('0'), i.e.
      they include a packet sequence number.

   o  OLSRv2 packets MAY include packet TLVs, however OLSRv2 itself does
      not specify any packet TLVs.

   o  All OLSRv2 messages, not limited to those defined in this
      document, include a full <msg-header> and hence have the noorig
      and nohops bits of <msg-semantics> cleared ('0').

   o  All OLSRv2 message defined in this document have the typedep bit,
      and all reserved bits of <msg-semantics> cleared ('0').

   Other options defined in [3] may be freely used, in particular any
   other values of <packet-semantics> or <tlv-semantics> consistent with
   its specification.

   OLSRv2 messages are sent using UDP, see Appendix C.

   The remainder of this section defines, within the framework of [3],
   message types and TLVs specific to OLSRv2.

6.1.  General OLSRv2 Message TLVs

   This document specifies two message TLVs, which can be applied to any
   OLSRv2 control messages, VALIDITY_TIME and INTERVAL_TIME.

6.1.1.  VALIDITY_TIME TLV

   All OLSRv2 messages specified in this document MUST include a



Clausen, et al.         Expires December 28, 2006              [Page 24]

Internet-Draft                   OLSRv2                        June 2006


   VALIDITY_TIME TLV, specifying a period following receipt of a
   message, after which the receiving node MUST consider the message
   content to no longer be valid (unless repeated in a later message).
   The validity time of a message MAY be specified to depend on the
   distance from the originator (i.e. the <hop-count> field in the
   message header as defined in [3]).  Thus, a VALIDITY_TIME TLV's value
   field MAY contain a sequence of pairs (time, hop limit) in increasing
   hop limit order; it MUST contain a final default value.

   This is an extended, and compatible, version of the VALIDITY_TIME TLV
   defined in [4].

   Thus, an instance of a VALIDITY_TIME TLV MAY have the following value
   field:

     <t_1><hl_1><t_2><hl_2> ... <t_i><hl_i> ....  <t_n><hl_n><t_default>

   Which would mean that the message carrying this VALIDITY_TIME TLV
   would have the following validity times:

   o  <t_1> in the interval from 0 (exclusive) to <hl_1> (inclusive)
      hops away from the originator;

   o  <t_i> in the interval from <hl_(i-1)> (exclusive) to <hl_i>
      (inclusive) hops away from the originator;

   o  <t_default> in the interval from <hl_n> (exclusive) to 255
      (inclusive) hops away from the originator.

   The VALIDITY_TIME message TLV specification is given in Table 1.

   +----------------+------+-------------------+-----------------------+
   |      Name      | Type |       Length      | Value                 |
   +----------------+------+-------------------+-----------------------+
   |  VALIDITY_TIME |  TBD |  (2*n+1) * 8 bits | {<time><hop_limit>}*  |
   |                |      |                   | <t_default>           |
   +----------------+------+-------------------+-----------------------+

                                  Table 1

   where n is the number of (time, hop_limit) pairs in the TLV (i.e. is
   equal to (<length>-1)/2, where <length> is the length of the TLV
   value field) and where <time> and <t_default> are represented as
   specified in [3].

6.2.  HELLO Messages

   A HELLO message in OLSRv2 is generated as specified in [4].



Clausen, et al.         Expires December 28, 2006              [Page 25]

Internet-Draft                   OLSRv2                        June 2006


   Additionally, an OLSRv2 node:

   o  MUST include TLV(s) with Type == MPR associated with all OLSRv2
      interface addresses included in the HELLO message with a TLV with
      Type == LINK_STATUS and Value == SYMMETRIC if that address is also
      included in the node's MPR Set (if there is more than one copy of
      the address, this applies to the specific copy of the address to
      which the TLV is associated);

   o  MUST NOT include any TLVs with Type == MPR associated with any
      other addresses;

   o  MAY include a message TLV with Type == WILLINGNESS, indicating the
      node's willingness to be selected as MPR.

6.2.1.  HELLO Message OLSRv2 Message TLVs

   In a HELLO message, a node MAY include a WILLINGNESS message TLV as
   specified in Table 2.

   +----------------+------+-------------------+-----------------------+
   |      Name      | Type |       Length      | Value                 |
   +----------------+------+-------------------+-----------------------+
   |   WILLINGNESS  |  TBD |       8 bits      | The node's            |
   |                |      |                   | willingness to be     |
   |                |      |                   | selected as MPR, any  |
   |                |      |                   | unused bits (based on |
   |                |      |                   | the maximum           |
   |                |      |                   | willingness value     |
   |                |      |                   | WILL_ALWAYS) are      |
   |                |      |                   | RESERVED and SHOULD   |
   |                |      |                   | be set to zero.       |
   +----------------+------+-------------------+-----------------------+

                                  Table 2

   A node's willingness to be selected as MPR ranges from WILL_NEVER
   (indicating that a node MUST NOT be selected as MPR by any node) to
   WILL_ALWAYS (indicating that a node MUST always be selected as MPR).

   If a node does not advertise a Willingness TLV in HELLO messages, the
   node MUST be assumed to have a willingness of WILL_DEFAULT.

6.2.2.  HELLO Message OLSRv2 Address Block TLVs

   In a HELLO message, a node MAY include MPR address block TLV(s) as
   specified in Table 3.




Clausen, et al.         Expires December 28, 2006              [Page 26]

Internet-Draft                   OLSRv2                        June 2006


   +----------------+------+-------------------+-----------------------+
   |      Name      | Type |       Length      | Value                 |
   +----------------+------+-------------------+-----------------------+
   |       MPR      |  TBD |       0 bits      | No value, i.e.        |
   |                |      |                   | novalue bit ([3]) set |
   +----------------+------+-------------------+-----------------------+

                                  Table 3

6.3.  TC Messages

   A TC message MUST contain:

   o  a message TLV with Type == CONT_SEQ_NUM, as specified in [3];

   o  a message TLV with Type == VALIDITY_TIME, as specified in
      Section 6.1.1;

   o  a first address block containing all of the node's OLSRv2
      interface addresses.  This is similar to the Local Interface Block
      specified in [4], however these addresses MUST be included in the
      same order in all copies of a given TC message, regardless of
      which interface it is transmitted on, and no OTHER_IF address
      block TLV(s) are required;

   o  additional address block(s) containing all addresses in the
      Advertised Address Set and Attached Network Set, the latter (only)
      with associated GATEWAY address block TLV(s), as specified in
      Section 6.4, both with associated PREFIX_LENGTH TLV(s), as
      specified in [3], as necessary.

   A TC message MAY contain:

   o  a message TLV INTERVAL_TIME, as specified in [4].

6.4.  TC Message: OLSRv2 Address Block TLVs

   In a TC message, a node MAY include GATEWAY address block TLV(s) as
   specified in Table 4.












Clausen, et al.         Expires December 28, 2006              [Page 27]

Internet-Draft                   OLSRv2                        June 2006


   +----------------+------+-------------------+-----------------------+
   |      Name      | Type |       Length      | Value                 |
   +----------------+------+-------------------+-----------------------+
   |     GATEWAY    |  TBD |       0 bits      | No value, i.e.        |
   |                |      |                   | novalue bit ([3]) set |
   +----------------+------+-------------------+-----------------------+

                                  Table 4











































Clausen, et al.         Expires December 28, 2006              [Page 28]

Internet-Draft                   OLSRv2                        June 2006


7.  HELLO Message Generation

   An OLSRv2 HELLO message is composed as defined in [4], with the
   following TLVs added:

   o  a message TLV with Type == WILLINGNESS and Value == the node's
      willingness to act as an MPR, MAY be included in the message;

   o  for each symmetric 1-hop neighbor OLSRv2 interface address which
      is included in the HELLO message with an associated TLV with Type
      == LINK_STATUS and is selected as an MPR (i.e. is present in the
      MPR Set), an address TLV with Type == MPR MUST be included, this
      SHOULD be associated with the same copy of the address as the TLV
      with Type == LINK_STATUS;

   o  for each 1-hop neighbor OLSRv2 interface address which is included
      in the HELLO message but is not selected as an MPR (i.e. is not
      present in the MPR Set), an address TLV with Type == MPR MUST NOT
      be included.

7.1.  HELLO Message: Transmission

   Messages are retransmitted in the packet/message format specified by
   [3] with the ALL-MANET-NEIGHBORS address as destination IP address
   and with TTL (IPv4) or hop limit (IPv6) equal to 1.


























Clausen, et al.         Expires December 28, 2006              [Page 29]

Internet-Draft                   OLSRv2                        June 2006


8.  HELLO Message Processing

   Subsequent to the processing of HELLO messages, as specified in [4],
   the node MUST:

   1.  Determine the willingness of the originating node to be an MPR
       by:

       *  if the HELLO message contains a message TLV with Type ==
          WILLINGNESS then the willingness is the value of that TLV,
          ignoring the reserved bits in that field;

       *  otherwise the willingness is WILL_DEFAULT.

   2.  Update each Link Tuple whose L_neighbor_iface_addr is present in
       the Local Interface Block of the HELLO message, with:

       *  L_willingness = the willingness of the originating node;

   3.  Update its MPR Selector Set, according to Section 8.1.

8.1.  Populating the MPR Selector Set

   On receiving a HELLO message, a node MUST:

   1.  If a node finds one of its own interface addresses with an
       associated TLV with Type == MPR in the HELLO message (indicating
       that the originator node has selected the receiving node as an
       MPR), the MPR Selector Set MUST be updated as follows:

       1.  For each address, henceforth neighbor address, in the Local
           Interface Block of the received HELLO message, where the
           neighbor address is present as an N_neighbor_iface_addr in a
           Symmetric Neighbor Tuple with N_STATUS == SYMMETRIC:

           1.  If there exists no MPR Selector Tuple with:

               -  MS_neighbor_iface_addr == neighbor address

               then a new MPR Selector Tuple is created with:

               -  MS_neighbor_iface_addr = neighbor address

           2.  The MPR Selector Tuple (new or otherwise) with:

               -  MS_neighbor_iface_addr == neighbor address

               is then modified as follows:



Clausen, et al.         Expires December 28, 2006              [Page 30]

Internet-Draft                   OLSRv2                        June 2006


               -  MS_time = current time + validity time

   2.  Otherwise if a node finds one of its own interface addresses with
       an associated TLV with Type == LINK_STATUS and Value == SYMMETRIC
       in the HELLO message (indicating, since there is no TLV with Type
       == MPR, that originator node has de-selected the receiving node
       as an MPR), the MPR Selector Set MUST be updated as follows:

       1.  All MPR Selector Tuples whose N_neighbor_iface_addr is in the
           Local Interface Block of the HELLO message are removed.

   MPR Selector Tuples are also removed upon expiration of MS_time, or
   upon symmetric link breakage as described in Section 8.2.

8.2.  Symmetric Neighborhood and 2-Hop Neighborhood Changes

   A node MUST also perform the following:

   1.  If a Link Tuple with L_STATUS == SYMMETRIC is removed, or its
       L_STATUS changes from SYMMETRIC to HEARD or LOST, and if that
       Link Tuple's L_neighbor_iface_addr is an MS_iface_addr of an MPR
       Selector Tuple, then that MPR Selector Tuple MUST be removed.

   2.  If any of:

       *  a Link Tuple is added with L_STATUS == SYMMETRIC, OR;

       *  a Link Tuple with L_STATUS == SYMMETRIC is removed, or its
          L_STATUS changes from SYMMETRIC to HEARD or LOST, or vice
          versa, OR;

       *  a 2-Hop Neighbor Tuple is added or removed, OR;

       *  the Neighbor Address Association Set is changed such that the
          subset of any NA_neighbor_iface_addr_list consisting of those
          addresses which are the L_neighbor_iface_addr of a Link Tuple
          with L_STATUS == SYMMETRIC is changed, including the cases of
          removal or addition of a Neighbor Address Association Tuple
          containing any such addresses;

       then the MPR Set MUST be recalculated.

   An additional HELLO message MAY be sent when the MPR Set changes, in
   addition to the cases specified in [4], and subject to the same
   constraints.






Clausen, et al.         Expires December 28, 2006              [Page 31]

Internet-Draft                   OLSRv2                        June 2006


9.  TC Message Generation

   A node with one or more OLSRv2 interfaces, and with a non-empty
   Advertised Neighbor Set or which acts as a gateway to an associated
   network which is to be advertised in the MANET, MUST generate TC
   messages.  A node with an empty Advertised Neighbor Set and which is
   not acting as such a gateway SHOULD also generate "empty" TC messages
   for a period A_HOLD_TIME after it last generated a non-empty TC
   message.  TC messages (non-empty and empty) are generated according
   to the following:

   1.  the TC message MUST contain a message TLV with Type ==
       CONT_SEQ_NUM and Value == ANSN from the Advertised Neighbor Set;

   2.  the TC message MUST contain a message TLV with Type ==
       VALIDITY_TIME and Value == T_HOLD_TIME as specified in
       Section 6.1.1;

   3.  the TC message MAY contain a message TLV with Type ==
       INTERVAL_TIME and Value == TC_INTERVAL as specified in [4];

   4.  the TC message MUST contain the addresses of all of its OLSRv2
       interfaces in its first address block, note that the TC message
       generated on all OLSRv2 interfaces MUST be identical (including
       having identical message sequence number) and hence these
       addresses are not ordered or otherwise identified according to
       the interface on which the TC message is transmitted;

   5.  the TC message MUST contain, in address blocks other than its
       first:

       1.  A_neighbor_iface_addr from each Advertised Neighbor Tuple;

       2.  the addresses of all associated hosts and networks for which
           this node is to act as a gateway and which is to be
           advertised in the MANET, each associated with a TLV with Type
           == GATEWAY.

   6.  the TC message MAY be fragmented, only by its originator.  It
       SHOULD be fragmented only if necessary; if the TC message is
       fragmented, a FRAGMENTATION TLV MUST be included, and each
       fragment SHOULD be indicated as "partially or wholly self
       contained" in it, and MUST indicate that the content sequence
       number (ANSN) is message type specific.







Clausen, et al.         Expires December 28, 2006              [Page 32]

Internet-Draft                   OLSRv2                        June 2006


9.1.  TC Message: Transmission

   TC messages are generated and transmitted periodically on all OLSRv2
   interfaces, with a default interval between two consecutive TC
   emissions by the same node of TC_INTERVAL.  TC messages MAY be
   generated in response to a change of contents (a change in ANSN, due
   to a change in the Advertised Neighbor Set or the advertised locally
   attached networks) but a node must respect a minimum interval of
   TC_MIN_INTERVAL between generated TC messages.

   TC messages SHOULD be generated with a message hop limit [3] greater
   than or equal to the expected network diameter (by default with a hop
   limit of 255).

   TC messages are transmitted with the ALL-MANET-NEIGHBORS multicast
   address as destination IP address and are forwarded according to the
   specification in Section 4.4.


































Clausen, et al.         Expires December 28, 2006              [Page 33]

Internet-Draft                   OLSRv2                        June 2006


10.  TC Message Processing

   When according to Section 4.3 a TC message is to be processed
   according to its type, this means that processing is carried out
   according to Section 10.1 and Section 10.2.  The timing of this
   processing depends on whether the TC message is a fragment, and if so
   whether it is "partially or wholly self-contained":

   o  if the message is not a fragment, then first Section 10.1 and then
      Section 10.2 are carried out when the message is received;

   o  if the message is a fragment which is "partially or wholly self-
      contained", then processing according to Section 10.1 is carried
      out when the message is received, and processing according to
      Section 10.2 is carried out when all matching fragments have been
      received and all processing according to Section 10.1 has been
      carried out;

   o  if the message is a fragment which is not "partially or wholly
      self-contained", then processing according to Section 10.1 is
      carried out when all matching fragments have been received, and
      processing according to Section 10.2 is carried out when all
      matching fragments have been received and all processing according
      to Section 10.1 has been carried out.

   For all processing purposes, "ANSN" is defined as being the value of
   the message TLV with Type == CONT_SEQ_NUM in the TC message.  If a TC
   message has no such TLV then the processing of Section 10.1 and
   Section 10.2 MUST NOT be carried out.  (Note that if the message is a
   fragment it will have already been discarded according to
   Section 4.3.)  If more than one TC message is processed according to
   Section 10.2 then these must have the same ANSN to be recognized as
   fragments of the same message.

10.1.  Single TC Message Processing

   For the purpose of this section, note the following:

   o  "validity time" is calculated from the VALIDITY_TIME message TLV
      in the TC message according to the specification in Section 6.1.1;

   o  "originator address" refers to the originator address in the TC
      message header;

   o  comparisons of sequence numbers are carried out as specified in
      Section 15.

   The TC message is processed as follows:



Clausen, et al.         Expires December 28, 2006              [Page 34]

Internet-Draft                   OLSRv2                        June 2006


   1.  the ANSN History Set is updated according to Section 10.1.1; if
       the TC message is indicated as discarded in that processing then
       the following steps are not carried out;

   2.  the Topology Set is updated according to Section 10.1.2;

   3.  the Attached Network Set is updated according to Section 10.1.3.

10.1.1.  Populating the ANSN History Set

   The node MUST update its ANSN History Set as follows:

   1.  if there is an ANSN History Tuple with:

       *  AH_orig_addr == originator address; AND

       *  AH_seq_number > ANSN

       then the TC message MUST be discarded;

   2.  otherwise create a new ANSN History Tuple with:

       *  AH_orig_addr = originator address;

       *  AH_seq_number = ANSN;

       *  AH_time = current time + validity time.

       possibly replacing an existing ANSN History Tuple with the same
       AH_orig_addr.

10.1.2.  Populating the Topology Set

   The node SHOULD update its Topology Set as follows:

   1.  for each address, henceforth local address, in the first address
       block in the TC message:

       1.  for each address, henceforth advertised address, in an
           address block other than the first in the TC message, and
           which does not have an associated TLV with Type == GATEWAY:

           1.  if there is a Topology Tuple with:

               T_dest_iface_addr == advertised address; AND






Clausen, et al.         Expires December 28, 2006              [Page 35]

Internet-Draft                   OLSRv2                        June 2006


               T_last_iface_addr == local address

               then update this Topology Tuple to have:

               T_seq_number = ANSN;

               T_time = current time + validity time

           2.  otherwise create a new Topology Tuple with:

               T_dest_iface_addr = advertised address;

               T_last_iface_addr = local address;

               T_seq_number = ANSN;

               T_time = current time + validity time.

10.1.3.  Populating the Attached Network Set

   The node SHOULD update its Attached Network Set as follows:

   1.  for each address, henceforth gateway address, in the first
       address block in the TC message:

       1.  for each address, henceforth network address, in an address
           block other than the first in the TC message, and which has
           an associated TLV with Type == GATEWAY:

           1.  if there is a Attached Network Tuple with:

               AN_net_addr == network address; AND

               AN_gw_iface_addr == gateway address

               then update this Attached Network Tuple to have:

               AN_seq_number = ANSN;

               AN_time = current time + validity time

           2.  otherwise create a new Attached Network Tuple with:

               AN_net_addr = network address;







Clausen, et al.         Expires December 28, 2006              [Page 36]

Internet-Draft                   OLSRv2                        June 2006


               AN_gw_iface_addr = gateway address

               AN_seq_number = ANSN;

               AN_time = current time + validity time

10.2.  Completed TC Message Processing

   The TC message(s) are processed as follows:

   1.  the Topology Set is updated according to Section 10.2.1;

   2.  the Attached Network Set is updated according to Section 10.2.2.

10.2.1.  Purging the Topology Set

   The Topology Set MUST be updated as follows:

   1.  for each address, henceforth local address, in the first address
       block of any of the TC messages, all Topology Tuples with:

       T_last_iface_addr == local address; AND

       T_seq_number < ANSN

       MUST be removed.

10.2.2.  Purging the Attached Network Set

   The Attached Network Set MUST be updated as follows:

   1.  for each address, henceforth local address, in the first address
       block of any of the TC messages, all Attached Network Tuples
       with:

       AN_gw_iface_addr == local address; AND

       AN_seq_number < ANSN

       MUST be removed.











Clausen, et al.         Expires December 28, 2006              [Page 37]

Internet-Draft                   OLSRv2                        June 2006


11.  Populating the MPR Set

   Each node MUST select, from among its symmetric 1-hop neighbors, a
   subset of nodes as MPRs.  This subset MUST be selected such that a
   message transmitted by the node, and retransmitted by all its MPRs,
   will be received by all of its symmetric strict 2-hop neighbors.

   Each node selects its MPR Set individually, utilizing the information
   in the Symmetric Neighbor Set, the 2-Hop Neighbor Set and the
   Neighborhood Address Association Set. Initially these sets will be
   empty, as will be the MPR Set. A node SHOULD recalculate its MPR Set
   when a relevant change is made to the Symmetric Neighbor Set, the
   2-Hop Neighbor Set or the Neighborhood Address Association Set.

   More specifically, a node MUST calculate MPRs per interface, the
   union of the MPR Sets of each interface make up the MPR Set for the
   node.  All OLSRv2 interfaces of nodes selected as MPRs with which the
   node has a symmetric link MUST be added to the MPR Set. Also
   symmetric 1-hop neighbor nodes with willingness WILL_NEVER (as
   recorded in the Link Set) MUST NOT be considered as MPRs.

   MPRs are used to flood control messages from a node into the network
   while reducing the number of retransmissions that will occur in a
   region.  Thus, the concept of MPR is an optimization of a classical
   flooding mechanism.  While it is not essential that the MPR Set is
   minimal, it is essential that all symmetric strict 2-hop neighbors
   can be reached through the selected MPR nodes.  A node MUST select an
   MPR Set such that any strict 2-hop neighbor is "covered" by at least
   one MPR node.  A node MAY select additional MPRs beyond the minimum
   set.  Keeping the MPR Set small ensures that the overhead of OLSRv2
   is kept at a minimum.

   Appendix A contains an example heuristic for selecting MPRs.


















Clausen, et al.         Expires December 28, 2006              [Page 38]

Internet-Draft                   OLSRv2                        June 2006


12.  Populating Derived Sets

   The Relay Set and the Advertised Neighbor Set of OLSRv2 are denoted
   derived sets, since updates to these sets are not directly a function
   of message exchanges, but rather are derived from updates to other
   sets, in particular the MPR Selector Set.

12.1.  Populating the Relay Set

   The Relay Set contains the set of neighbor addresses, for which a
   node is supposed to relay broadcast traffic.  This set SHOULD at
   least contain all addresses in the MPR Selector Set. This set MAY
   contain additional symmetric 1-hop neighbor addresses.

12.2.  Populating the Advertised Neighbor Set

   The Advertised Neighbor Set contains the set of OLSRv2 interface
   addresses of those 1-hop neighbors to which a node advertises a
   symmetric link in TC messages.  This set SHOULD at least contain all
   of the OLSRv2 interface addresses of the nodes in the MPR Selector
   Set (i.e. all addresses associated with an MPR Selector node through
   the Neighborhood Address Association Set, that is, appearing in the
   same NA_neighbor_iface_addr_list as any MS_neighbor_iface_addr).
   This set MAY also contain OLSRv2 interface addresses of other
   symmetric 1-hop neighbors.

   Whenever an address is removed from the Advertised Neighbor Set, the
   ANSN MUST be incremented.  Whenever an address is added to the
   Advertised Neighbor Set, the ANSN MUST be incremented.






















Clausen, et al.         Expires December 28, 2006              [Page 39]

Internet-Draft                   OLSRv2                        June 2006


13.  Routing Table Calculation

   The Routing Set is updated when a change (an entry appearing or
   disappearing, or changing between SYMMETRIC and LOST) is detected in:

   o  the Link Set, OR;

   o  the Neighbor Address Association Set, OR;

   o  the 2-Hop Neighbor Set, OR;

   o  the Topology Set, OR;

   o  the Attached Network Set.

   Note that some changes to these sets do not necessitate a change to
   the Routing Set, in particular changes to the Link Set which do not
   involve Link Tuples with L_STATUS == SYMMETRIC (either before or
   after the change), similar changes to the Neighbor Address
   Association Set. A node MAY avoid updating the Routing Set in such
   cases.

   Updates to the Routing Set does not generate or trigger any messages
   to be transmitted.  The state of the Routing Set SHOULD, however, be
   reflected in the IP routing table by adding and removing entries from
   the routing table as appropriate.

   To construct the Routing Set of node X, a shortest path algorithm is
   run on the directed graph containing

   o  the arcs X -> Y where there exists a Link Tuple with Y as
      L_neighbor_iface_addr and L_STATUS == SYMMETRIC (i.e.  Y is a
      symmetric 1-hop neighbor of X), AND;

   o  the arcs Y -> Z where Y is added as above and the Link Tuple with
      Y as L_neighbor_iface_addr has L_willingness not equal to
      WILL_NEVER, and there exists a 2-Hop Neighbor Tuple with Y as
      N2_neighbor_iface_addr and Z as N2_2hop_iface_addr (i.e.  Z is a
      symmetric 2-hop neighbor of Z through Y, which does not have
      willingness WILL_NEVER), AND;

   o  the arcs U -> V, where there exists a Topology Tuple with U as
      T_last_iface_addr and V as T_dest_iface_addr (i.e. this is an
      advertised link in the network).

   The graph is complemented with:





Clausen, et al.         Expires December 28, 2006              [Page 40]

Internet-Draft                   OLSRv2                        June 2006


   o  arcs Y -> W where there exists a Link Tuple with Y as
      L_neighbor_iface_addr and L_STATUS == SYMMETRIC and a Neighborhood
      Address Association Tuple with Y and W both contained in
      NA_neighbor_iface_addr_list (i.e.  Y and W are both addresses of
      the same symmetric 1-hop neighbor), AND;

   o  arcs U -> T where there exists an Attached Network Tuple with U as
      AN_net_addr and T as AN_gw_iface_addr (i.e.  U is a gateway to
      network T).

   The following procedure is given as an example for (re-)calculating
   the Routing Set using a variation of Dijkstra's algorithm.  Thus:

   1.  All Routing Tuples are removed.

   2.  For each Link Tuple with L_STATUS == SYMMETRIC, a new Routing
       Tuple is added with:

       *  R_dest_addr = L_neighbor_iface_addr of the Link Tuple;

       *  R_next_iface_addr = L_neighbor_iface_addr of the Link Tuple;

       *  R_dist = 1;

       *  R_local_iface_addr = L_local_iface_addr of the Link Tuple.

   3.  For each Neighbor Address Association Tuple, for which two
       addresses A1 and A2 are in NA_neighbor_iface_addr_list where:

       *  there is a Routing Tuple with:

          +  R_dest_addr == A1

       *  and there is no Routing Tuple with:

          +  R_dest_addr == A2

       then a Routing Tuple is added with:

       *  R_dest_addr = A2;

       *  R_next_iface_addr = R_next_iface_addr of the Routing Tuple in
          which R_dest_addr == A1;

       *  R_dist = 1;

       *  R_local_iface_addr = R_local_iface_addr of the Routing Tuple
          in which R_dest_addr == A1.



Clausen, et al.         Expires December 28, 2006              [Page 41]

Internet-Draft                   OLSRv2                        June 2006


   4.  The following procedure, which adds Routing Tuples for
       destination nodes h+1 hops away, MUST be executed for each value
       of h, starting with h=2 and incrementing by 1 for each iteration.
       The execution MUST stop if no new Routing Tuples are added in an
       iteration.

       1.  For each Topology Tuple, if

           +  T_dest_iface_addr is not equal to R_dest_addr of any
              Routing Tuple, AND;

           +  T_last_iface_addr is equal to R_dest_addr of a Routing
              Tuple whose R_dist == h;

           then a new Routing Tuple MUST be added, with:

           +  R_dest_addr = T_dest_iface_addr;

           +  R_next_iface_addr = R_next_iface_addr of the Routing Tuple
              whose R_dest_addr == T_last_iface_addr;

           +  R_dist = h+1;

           +  R_local_iface_addr = R_local_iface_addr of the Routing
              Tuple whose R_dest_addr == T_last_iface_addr.

           Several Topology Tuples may be used to select a next hop
           R_next_iface_addr for reaching the address R_dest_addr.  When
           h == 1, ties should be broken such that nodes with highest
           willingness are preferred, and between nodes of equal
           willingness, MPR selectors are preferred over non-MPR
           selectors.

       2.  After the above iteration has completed, if h == 1, for each
           2-Hop Neighbor Tuple where:

           +  N2_2hop_iface_addr is not equal to R_dest_addr of any
              Routing Tuple, AND;

           +  N2_neighbor_iface_addr has a willingness (i.e. the
              L_willingness of the Link Tuple of which
              L_neighbor_iface_addr == N2_neighbor_iface_addr) which is
              not equal to WILL_NEVER;

           a Routing Tuple is added with:

           +  R_dest_addr = N2_2hop_iface_addr of the 2-Hop Neighbor
              Tuple;



Clausen, et al.         Expires December 28, 2006              [Page 42]

Internet-Draft                   OLSRv2                        June 2006


           +  R_next_iface_addr = R_next_iface_addr of the Routing Tuple
              in which R_dest_addr == N2_neighbor_iface_addr;

           +  R_dist = 2;

           +  R_local_iface_addr = R_local_iface_addr of the Routing
              Tuple in which R_dest_addr == N2_neighbor_iface_addr.

   5.  For each Attached Network Tuple, if

       *  AN_net_addr is not equal to R_dest_addr of any Routing Tuple,
          AND;

       *  AN_gw_iface_addr is equal to R_dest_addr of a Routing Tuple;

       then a new Routing Tuple MUST be added, with:

       *  R_dest_addr = AN_net_addr;

       *  R_next_iface_addr = R_next_iface_addr of the Routing Tuple
          whose R_dest_addr == AN_gw_iface_addr;

       *  R_dist = R_dist of the Routing Tuple whose R_dest_addr ==
          AN_gw_iface_addr;

       *  R_local_iface_addr = R_local_iface_addr of the Routing Tuple
          whose R_dest_addr == AN_gw_iface_addr.

       If more than one Attached Network Tuple has the same AN_net_addr,
       then more than one Routing Tuple MUST NOT be added, and the added
       Routing Tuple MUST have minimum R_dist.




















Clausen, et al.         Expires December 28, 2006              [Page 43]

Internet-Draft                   OLSRv2                        June 2006


14.  Proposed Values for Constants

   This section list the values for the constants used in the
   description of the protocol.

14.1.  Neighborhood Discovery Constants

   The constants HELLO_INTERVAL, REFRESH_INTERVAL, HELLO_MIN_INTERVAL,
   H_HOLD_TIME, L_HOLD_TIME, N_HOLD_TIME and C are used as in [4].

14.2.  Message Intervals

   o  TC_INTERVAL = 5 seconds

   o  TC_MIN_INTERVAL = TC_INTERVAL/4

14.3.  Holding Times

   o  T_HOLD_TIME = 3 x TC_INTERVAL

   o  A_HOLD_TIME = T_HOLD_TIME

   o  P_HOLD_TIME = 30 seconds

   o  FG_HOLD_TIME = 30 seconds

   o  RX_HOLD_TIME = 30 seconds

   o  FW_HOLD_TIME = 30 seconds

14.4.  Willingness

   o  WILL_NEVER = 0

   o  WILL_DEFAULT = 3

   o  WILL_ALWAYS = 7














Clausen, et al.         Expires December 28, 2006              [Page 44]

Internet-Draft                   OLSRv2                        June 2006


15.  Sequence Numbers

   Sequence numbers are used in OLSRv2 with the purpose of discarding
   "old" information, i.e. messages received out of order.  However with
   a limited number of bits for representing sequence numbers, wrap-
   around (that the sequence number is incremented from the maximum
   possible value to zero) will occur.  To prevent this from interfering
   with the operation of OLSRv2, the following MUST be observed when
   determining the ordering of sequence numbers.

   The term MAXVALUE designates in the following one more than the
   largest possible value for a sequence number.  For a 16 bit sequence
   number (as are those defined in this specification) MAXVALUE is
   65536.

   The sequence number S1 is said to be "greater than" the sequence
   number S2 if:

   o  S1 > S2 AND S1 - S2 <= MAXVALUE/2 OR

   o  S2 > S1 AND S2 - S1 > MAXVALUE/2

   Thus when comparing two messages, it is possible - even in the
   presence of wrap-around - to determine which message contains the
   most recent information.


























Clausen, et al.         Expires December 28, 2006              [Page 45]

Internet-Draft                   OLSRv2                        June 2006


16.  IANA Considerations

16.1.  Multicast Addresses

   A well-known multicast address, ALL-MANET-NEIGHBORS, must be
   registered and defined for both IPv6 and IPv4.  The addressing scope
   is link-local, i.e. this address is similar to the all nodes/routers
   multicast address of IPv6 in that it targets all OLSRv2 capable nodes
   adjacent to the originator of an IP datagram.

16.2.  Message Types

     OLSRv2 defines one message type, which must be allocated from the
                "Assigned Message Types" repository of [3]

   +--------------------+-------+--------------------------------------+
   |      Mnemonic      | Value | Description                          |
   +--------------------+-------+--------------------------------------+
   |         TC         |  TBD  | Topology Control (global signaling)  |
   +--------------------+-------+--------------------------------------+

                                  Table 5

16.3.  TLV Types

   OLSRv2 defines one Message TLV type, which must be allocated from the
              "Assigned message TLV Types" repository of [3]

   +--------------------+-------+--------------------------------------+
   |      Mnemonic      | Value | Description                          |
   +--------------------+-------+--------------------------------------+
   |     WILLINGNESS    |  TBD  | Specifies a node's willingness to    |
   |                    |       | act as a relay and to partake in     |
   |                    |       | network formation                    |
   +--------------------+-------+--------------------------------------+

                                  Table 6














Clausen, et al.         Expires December 28, 2006              [Page 46]

Internet-Draft                   OLSRv2                        June 2006


    OLSRv2 defines one Address Block TLV type, which must be allocated
       from the "Assigned address block TLV Types" repository of [3]

   +--------------------+-------+--------------------------------------+
   |      Mnemonic      | Value | Description                          |
   +--------------------+-------+--------------------------------------+
   |         MPR        |  TBD  | Specifies that a given address is    |
   |                    |       | selected as MPR                      |
   +--------------------+-------+--------------------------------------+

                                  Table 7








































Clausen, et al.         Expires December 28, 2006              [Page 47]

Internet-Draft                   OLSRv2                        June 2006


17.  References

17.1.  Normative References

   [1]  Clausen, T. and P. Jacquet, "The Optimized Link State Routing
        Protocol", RFC 3626, October 2003.

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

   [3]  Clausen, T., Dean, J., Dearlove, C., and C. Adjih, "Generalized
        MANET Packet/Message Format", work in
        progress draft-ietf-manet-packetbb-01.txt, June 2006.

   [4]  Clausen, T., Dean, J., and C. Dearlove, "MANET Neighborhood
        Discovery Protocol (NHDP)", work in
        progress draft-ietf-manet-nhdp-00.txt, June 2006.

17.2.  Informative References

   [5]  Atkins, D., Stallings, W., and P. Zimmermann, "PGP Message
        Exchange Formats", RFC 1991, August 1996.

   [6]  ETSI, "ETSI STC-RES10 Committee.  Radio equipment and systems:
        HIPERLAN type 1, functional specifications ETS 300-652",
        June 1996.

   [7]  Jacquet, P., Minet, P., Muhlethaler, P., and N. Rivierre,
        "Increasing reliability in cable free radio LANs: Low level
        forwarding in HIPERLAN.", 1996.

   [8]  Qayuum, A., Viennot, L., and A. Laouiti, "Multipoint relaying:
        An efficient technique for flooding in mobile wireless
        networks.", 2001.

















Clausen, et al.         Expires December 28, 2006              [Page 48]

Internet-Draft                   OLSRv2                        June 2006


Appendix A.  Example Heuristic for Calculating MPRs

   The following specifies a proposed heuristic for selection of MPRs.

   In graph theory terms, MPR computation is a "set cover" problem,
   which is a difficult optimization problem, but for which an easy and
   efficient heuristics exist: the so-called "Greedy Heuristic", a
   variant of which is described here.  In simple terms, MPR computation
   constructs an MPR Set that enables a node to reach any symmetric
   2-hop neighbors by relaying through an MPR node.

   There are several peripheral issues that the algorithm needs to
   address.  The first one is that some nodes have some willingness
   WILL_NEVER.  The second one is that some nodes may have several
   interfaces.

   The algorithm hence can be summarized by:

   o  All 1-hop neighbor nodes with willingness equal to WILL_NEVER MUST
      ignored in the following algorithm: they are not considered as
      1-hop neighbors (hence not used as MPRs).

   o  Because link sensing is performed by interface, the local network
      topology is best described in terms of links: hence the algorithm
      is considering 1-hop neighbor OLSRv2 interfaces, and 2-hop
      neighbor OLSRv2 interfaces (and their addresses).  Additionally,
      asymmetric links are ignored.  This is reflected in the
      definitions below.

   o  MPR computation is performed on each interface of the node: on
      each interface I, the node MUST select some neighbor interfaces,
      so that all 2-hop neighbor interfaces are reached.

   From now on, MPR calculation will be described for one interface I on
   the node, and the following terminology will be used in describing
   the heuristics:

   neighbor interface (of I) - An OLSRv2 interface of a 1-hop neighbor
      to which there exist a symmetric link using interface I.

   N  - the set of such neighbor interfaces

   2-hop neighbor interface (of I) An interface of a symmetric strict
      2-hop neighbor which can be reached from a neighbor interface for
      I.






Clausen, et al.         Expires December 28, 2006              [Page 49]

Internet-Draft                   OLSRv2                        June 2006


   N2 - the set of such 2-hop neighbor interfaces

   D(y): - the degree of a 1-hop neighbor interface y (where y is a
      member of N), is defined as the number of symmetric neighbor
      interfaces of node y which are in N2

   MPR Set - the set of the neighbor interfaces selected as MPRs.

   The proposed heuristic selects iteratively some interfaces from N as
   MPRs in order to cover 2-hop neighbor interfaces from N2, as follows:

   1.  Start with an MPR Set made of all members of N with L_willingness
       equal to WILL_ALWAYS

   2.  Calculate D(y), where y is a member of N, for all interfaces in
       N.

   3.  Add to the MPR Set those interfaces in N, which are the *only*
       nodes to provide reachability to an interface in N2.  For
       example, if interface B in N2 can be reached only through a
       symmetric link to interface A in N, then add interface B to the
       MPR Set. Remove the interfaces from N2 which are now covered by a
       interface in the MPR Set.

   4.  While there exist interfaces in N2 which are not covered by at
       least one interface in the MPR Set:

       1.  For each interface in N, calculate the reachability, i.e.,
           the number of interfaces in N2 which are not yet covered by
           at least one node in the MPR Set, and which are reachable
           through this neighbor interface;

       2.  Select as an MPR the interface with highest L_willingness
           among the interfaces in N with non-zero reachability.  In
           case of multiple choice select the interface which provides
           reachability to the maximum number of interfaces in N2.  In
           case of multiple interfaces providing the same amount of
           reachability, select the interface as MPR whose D(y) is
           greater.  Remove the interfaces from N2 which are now covered
           by an interface in the MPR Set.

   Other algorithms, as well as improvements over this algorithm, are
   possible.  For example:

   o  Assume that in a multiple interface scenario there exists more
      than one link between nodes 'a' and 'b'.  If node 'a' has selected
      node 'b' as MPR for one of its interfaces, then node 'b' can be
      selected as MPR with minimal performance loss by any other



Clausen, et al.         Expires December 28, 2006              [Page 50]

Internet-Draft                   OLSRv2                        June 2006


      interfaces on node 'a'.

   o  In a multiple interface scenario MPRs are selected for each
      interface of the selecting node, providing full coverage of all
      2-hop nodes accessible through that interface.  The overall MPR
      Set is then the union of these sets.  These sets do not however
      have to be selected independently, if a node is selected as an MPR
      for one interface it may be automatically added to the MPR
      selection for other interfaces.










































Clausen, et al.         Expires December 28, 2006              [Page 51]

Internet-Draft                   OLSRv2                        June 2006


Appendix B.  Heuristics for Generating Control Traffic

   A node creates HELLO messages and TC messages as specified in
   Section 7 and Section 9, the former being a modification of the
   specification in [4].  The heuristics for creation of HELLO messages
   in [4] remain applicable, with the division of the address TLVs with
   Type == LINK_STATUS and Value == SYMMETRIC into separate ranges with
   and without an associated TLV with Type == MPR.  The heuristics for
   collection of addresses are also generally applicable to TC messages,
   excepting that the first address block is not sorted as the Local
   Interface Block of a HELLO message is, and that other addresses
   recorded in TC messages are divided into those with and without a TLV
   with Type == GATEWAY.  These should be ordered so that the range of
   addresses without that TLV is continuous (and it is suggested that
   the range without is also continuous).




































Clausen, et al.         Expires December 28, 2006              [Page 52]

Internet-Draft                   OLSRv2                        June 2006


Appendix C.  Protocol and Port Number

   Packets in OLSRv2 are communicated using UDP.  Port 698 has been
   assigned by IANA for exclusive usage by the OLSR (v1 and v2)
   protocol.














































Clausen, et al.         Expires December 28, 2006              [Page 53]

Internet-Draft                   OLSRv2                        June 2006


Appendix D.  Packet and Message Layout

   This section specifies the translation from the abstract descriptions
   of packets employed in the protocol specification, and the bit-layout
   packets actually exchanged between the nodes.

Appendix D.1.  OLSRv2 Packet Format

   The basic layout of an OLSRv2 packet is as described in [3].  However
   the following points should be noted.

   OLSRv2 uses only packets with a packet header including a packet
   sequence number, either with or without a packet TLV block.  Thus all
   OLSRv2 packets have the layout of either


      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 0| Reserved  |0|0|    Packet Sequence Number     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     |                       Message + Padding                       |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     :                              ...                              :
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     |                       Message + Padding                       |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   or















Clausen, et al.         Expires December 28, 2006              [Page 54]

Internet-Draft                   OLSRv2                        June 2006


      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 0| Reserved  |1|0|    Packet Sequence Number     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     |                       Packet TLV Block                        |
     |                                                               |
     |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                               |            Padding            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     |                       Message + Padding                       |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     :                              ...                              :
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     |                       Message + Padding                       |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   The reserved bits marked Resv SHOULD be cleared ('0').  The octets
   indicated as Padding are optional and MAY be omitted; if not omitted
   they SHOULD be used to pad to a 32 bit boundary and MUST all be zero.

   OLSRv2 uses only messages with a complete message header.  Thus all
   OLSRv2 messages, plus padding if any, have the following layout.


      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Message Type  |  Resv   |N|0|0|         Message Size          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                      Originator Address                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Hop Limit   |   Hop Count   |    Message Sequence Number    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     |                         Message Body                          |
     |                                                               |
     |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                               |            Padding            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



Clausen, et al.         Expires December 28, 2006              [Page 55]

Internet-Draft                   OLSRv2                        June 2006


   The reserved bits marked Resv SHOULD be cleared ('0').  In standard
   OLSRv2 messages (HELLO and TC) the type dependent sequence number bit
   marked N SHOULD also be cleared ('0').

   The layouts of the message body, address block, TLV block and TLV are
   as in [3], allowing all options.  Standard (HELLO and TC) messages
   contain a first address block which contains local interface address
   information, all other address blocks contain neighbor interface
   address information (or for a TC message address information for
   which it is a gateway) specific to the message type.

   An example HELLO message, using IPv4 (four octet) addresses is as
   follows.  The overall message length is 56 octets (it does not need
   padding).  The message has a hop limit of 1 and a hop count of 0, as
   sent by its originator.

   The message has a message TLV block with content length 12 octets
   containing three message TLVs.  These TLVs represent message validity
   time, message interval time and willingness.  Each uses a TLV with
   semantics value 4, indicating no start and stop indexes are included,
   and each has a value length of 1 octet.

   The first address block contains a 1 local interface address, with
   head length 4.  This is equal to the address length, thus no tail or
   mid sections of the address are included.  This address block has no
   TLVs (the TLV block content length is 0 octets).

   The second, and last, address block reports 4 neighbor interface
   addresses, with address head length 3 octets, and no tail octet (zero
   tail length).  Thus each mid address section is of length one octet.
   The following address TLV block (content length 11 octets) includes
   two TLVs.

   The first of these TLVs reports the link status of all four neighbors
   in a single multivalue TLV, the first two addresses are HEARD, the
   last two addresses are SYMMETRIC.  The TLV semantics value of 12
   indicates, in addition to that this is a multivalue TLV, that no
   start index and stop index are included, hence values for all
   addresses are included.  The TLV value length of 4 octets indicates
   one octet per value per address.

   The second of these TLV indicates that the last address (start index
   3, stop index 3) is an MPR.  This TLV has no value, or value length,
   fields, as indicated by its semantics octet being equal to 1.







Clausen, et al.         Expires December 28, 2006              [Page 56]

Internet-Draft                   OLSRv2                        June 2006


      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     HELLO     |0 0 0 0 0 0 0 0|0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                      Originator Address                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 1|0 0 0 0 0 0 0 0|    Message Sequence Number    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0| VALIDITY_TIME |0 0 0 0 0 1 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 1|     Value     | INTERVAL_TIME |0 0 0 0 0 1 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 1|     Value     |  WILLINGNESS  |0 0 0 0 0 1 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 1|     Value     |0 0 0 0 0 0 0 1|0 0 0 0 0 1 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             Head                              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0|0 0 0 0 0 1 0 0|0 0 0 0 0 0 1 1|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Head                      |      Mid      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      Mid      |      Mid      |      Mid      |0 0 0 0 0 0 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 1 0 1 1|  LINK_STATUS  |0 0 0 0 1 1 0 0|0 0 0 0 0 1 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     HEARD     |     HEARD     |   SYMMETRIC   |   SYMMETRIC   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      MPR      |0 0 0 0 0 0 0 1|0 0 0 0 0 0 1 1|0 0 0 0 0 0 1 1|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   An example TC message, using IPv4 (four octet) addresses, is as
   follows.  The overall message length is 64 octets, it also does not
   need padding.

   The message has a message TLV block with content length 13 octets
   containing three TLVs.  The first TLV is a content sequence number
   TLV used to carry the 2 octet ANSN.  The semantics value is 4
   indicating that no index fields are included.  The other two TLVs are
   validity and interval times as for the HELLO message above.

   The message has three address blocks.  The first address block
   contains 3 local interface addresses (with common head length 2
   octets) and has a TLV block with content length 0 octets.

   The other two address blocks contain neighbor interface addresses.



Clausen, et al.         Expires December 28, 2006              [Page 57]

Internet-Draft                   OLSRv2                        June 2006


   The first contains 3 addresses and has an empty TLV block (content
   length 0 octets).  The second contains 1 address.  The head octet
   (hex 82) indicates a head length of two octets and the presence of a
   tail octet.  The tail octet (hex 82) indicates a tail length of two
   octets, all zero bits and not included.  The following TLV block
   (content length 6 octets) includes two TLVs, the first (semantics
   value 4 indicating no indexes are needed) indicates that the address
   has a netmask, with length given by the value (of length 1 octet) of
   16.  Thus this address is Head.0.0/16.  The second TLV indicates that
   the originating node is a gateway to this network, the TLV semantics
   value of 5 indicates that neither indexes nor value are needed.


      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      TC       |0 0 0 0 0 0 0 0|0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                      Originator Address                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Hop Limit   |   Hop Count   |    Message Sequence Number    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 1| CONT_SEQ_NUM  |0 0 0 0 0 1 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 1 0|         Value (ANSN)          | VALIDITY_TIME |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 1 0 0|0 0 0 0 0 0 0 1|     Value     | INTERVAL_TIME |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 1 0 0|0 0 0 0 0 0 0 1|     Value     |0 0 0 0 0 0 1 1|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 1 0|             Head              |      Mid      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Mid (cont)   |              Mid              |      Mid      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Mid (cont)   |0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0|0 0 0 0 0 0 1 1|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 1 0|             Head              |      Mid      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Mid (cont)   |              Mid              |      Mid      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Mid (cont)   |0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0|0 0 0 0 0 0 0 1|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 0 0 0 0 0 1 0|             Head              |1 0 0 0 0 0 1 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0| PREFIX_LENGTH |0 0 0 0 0 1 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 0 0 0 0 1|0 0 0 1 0 0 0 0|    GATEWAY    |0 0 0 0 0 1 0 1|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



Clausen, et al.         Expires December 28, 2006              [Page 58]

Internet-Draft                   OLSRv2                        June 2006


Appendix E.  Node Configuration

   OLSRv2 does not make any assumption about node addresses, other than
   that each node is assumed to have at least one a unique and routable
   IP address for each interface that it has which participates in the
   MANET.

   When applicable, a recommended way of connecting an OLSRv2 network to
   an existing IP routing domain is to assign an IP prefix (under the
   authority of the nodes/gateways connecting the MANET with the routing
   domain) exclusively to the OLSRv2 area, and to configure the gateways
   statically to advertise routes to that IP sequence to nodes in the
   existing routing domain.






































Clausen, et al.         Expires December 28, 2006              [Page 59]

Internet-Draft                   OLSRv2                        June 2006


Appendix F.  Jitter

   In a wireless network, simultaneous packet transmission by nearby
   nodes is undesirable as, depending on the medium access control and
   other lower layer mechanisms, the interference between these messages
   may cause at best increased delay, and at worst complete packet loss
   by both nodes.  This is often particularly true when using a
   broadcast mechanism, such as is used by OLSRv2 packets.

   The problems of simultaneous packet transmission in OLSRv2 are
   increased by the following features of the protocol:

   o  If two nodes send packets containing regularly scheduled messages
      of the same type at the same time, then if, as is typical, they
      are using the same message interval, further transmissions of
      these messages will also be at the same time, and will also
      interfere.  This node synchronization could even result in
      complete operational failure of these nodes.

   o  OLSRv2 allows nodes to respond to changes in their circumstances,
      usually changes in the neighborhood, with immediate messages of
      appropriate types.  Nearby nodes will have overlapping
      neighborhoods, and may respond to the same change in
      circumstances.  For example a single link failure can result in a
      node having to change its MPR Set, and then two or more of its
      neighbors having changed MPR status responding simultaneously with
      revised TC messages, whose packets may interfere.

   o  When a node sends such a responsive message, there is no apparent
      reason why it should not restart its message schedule of the
      appropriate type of message.  This results in nodes responding to
      the same change not just sending single simultaneous packets, but
      becoming synchronized.

   o  Nodes also forward messages they receive from other nodes.  Two
      nearby nodes will thus commonly receive and forward the same
      message.  The consequent packet transmissions can easily interfere
      with each other.

   Because interference can easily occur, is self-reinforcing, and is
   anything from undesirable to catastrophic, mechanisms to minimize it,
   and to break synchronization of nodes, SHOULD be used in OLSRv2.
   These all make a deliberate adjustment to the timing, known as
   "jitter".  Three cases exist:

   o  When a node generates a control message periodically, it would
      normally wait for a delay equal to MESSAGE_INTERVAL (e.g.
      HELLO_INTERVAL for HELLO messages or TC_INTERVAL for TC messages)



Clausen, et al.         Expires December 28, 2006              [Page 60]

Internet-Draft                   OLSRv2                        June 2006


      between two transmissions of messages of that type.  This delay
      SHOULD be mitigated by subtracting a jitter time, so that the
      delay between consecutive transmissions of a messages of the same
      type SHOULD be equal to MESSAGE_INTERVAL - jitter, where jitter is
      a random value whose generation is discussed below.  Note that
      this is a deliberately asymmetric process.  It ensures that the
      message interval does not exceed MESSAGE_INTERVAL (which leaves
      MESSAGE_INTERVAL an appropriate value for reporting in an
      INTERVAL_TIME message TLV) and also allows different nodes to
      become completely desynchronized as each interval is based on the
      previous actual transmission time, not on a fixed clock of period
      MESSAGE_INTERVAL.

   o  When a node responds to an externally triggered change in
      circumstances, it SHOULD delay the transmission of a message in
      response by a random jitter time.  It MAY restart its schedule of
      messages of the appropriate type based on that new time.  If such
      a message is delayed due to the need to respect the appropriate
      MESSAGE_MIN_INTERVAL (e.g.  HELLO_MIN_INTERVAL for HELLO messages
      or TC_MIN_INTERVAL for TC messages) then the node MAY reduce this
      minimum interval by a jitter time as the normal message interval
      is reduced (thus allowing MESSAGE_MIN_INTERVAL to equal
      MESSAGE_INTERVAL even when using jitter).

   o  When a node forwards a message, it SHOULD delay the message
      retransmission by a random jitter time.

   In the first and second cases above, the maximum jitter time may be
   specified by a parameter MAXJITTER.  It is necessary only that this
   be significantly less than each MESSAGE_INTERVAL, and less than each
   MESSAGE_MIN_INTERVAL.  Normally the actual value of the jitter
   (reduction in message interval or delay of responsive message) SHOULD
   be uniformly generated in the interval 0 <= jitter <= MAXJITTER,
   however this may be modified as indicated below.

   In the third case above, a message SHOULD be delayed by a jitter
   value which is significantly less than the originating node's message
   interval.  This MAY be available in an INTERVAL_TIME message TLV in
   the message to be forwarded.  If not so available, a node MAY
   estimate an acceptable maximum jitter by any other means available to
   it, which may be by use of its own MAXJITTER parameter for as long as
   this works.  In a network in which this is likely to be unsuccessful,
   nodes SHOULD include an INTERVAL_TIME message TLV in messages which
   are to be forwarded.

   In all cases, as well as constraints imposed by message intervals and
   message minimum intervals, the maximum jitter delay SHOULD only be as
   large as is required to achieve the required objective of minimizing



Clausen, et al.         Expires December 28, 2006              [Page 61]

Internet-Draft                   OLSRv2                        June 2006


   interference due to synchronization.  This is because all jitter, and
   forwarding jitter in particular, is undesirable for otherwise ideal
   functioning of the network.

   Because of differing parameters, or due to responsive messages with a
   small minimum message interval, a node may receive a message from an
   originating node while still waiting to forward an earlier message of
   the same type originating from the same node.  The forwarding node
   SHOULD NOT allow forwarding jitter delay to reorder these messages.
   A node MAY discard the earlier message, transmitting the later
   message no later than the earlier message was due to be
   retransmitted, if, and only if, it can guarantee that this will not
   have any adverse effect.

   OLSRv2 messages are transmitted in potentially multi-message packets.
   Whilst a packet is a hop by hop construct and it is the messages in
   it which are forwarded, if a number of messages are received in the
   same packet, they SHOULD (if their maximum jitter delays are
   compatible) be permitted to be forwarded in the same new packet.
   This may be accomplished by generating the same random delay for all
   messages received in a single packet.  Furthermore, the opportunity
   to combine messages to be forwarded from different sources, and
   locally generated messages in a single packet SHOULD be allowed even
   when this means adjusting (forwards or backwards) the strictly
   uniformly generated random jitter times, however these SHOULD NOT be
   allowed to exceed their maximum value, nor allow a message interval
   to be exceeded, nor compromise the purpose of jitter.  (It is for
   this reason that messages in the same packet should be given the same
   random jitter, as giving them independent jitter values but then, for
   example, allowing all to be sent with the earliest would reduce the
   mean jitter delay.)




















Clausen, et al.         Expires December 28, 2006              [Page 62]

Internet-Draft                   OLSRv2                        June 2006


Appendix G.  Security Considerations

   Currently, OLSRv2 does not specify any special security measures.  As
   a proactive routing protocol, OLSRv2 makes a target for various
   attacks.  The various possible vulnerabilities are discussed in this
   section.

Appendix G.1.  Confidentiality

   Being a proactive protocol, OLSRv2 periodically diffuses topological
   information.  Hence, if used in an unprotected wireless network, the
   network topology is revealed to anyone who listens to OLSRv2 control
   messages.

   In situations where the confidentiality of the network topology is of
   importance, regular cryptographic techniques, such as exchange of
   OLSRv2 control traffic messages encrypted by PGP [5] or encrypted by
   some shared secret key, can be applied to ensure that control traffic
   can be read and interpreted by only those authorized to do so.

Appendix G.2.  Integrity

   In OLSRv2, each node is injecting topological information into the
   network through transmitting HELLO messages and, for some nodes, TC
   messages.  If some nodes for some reason, malicious or malfunction,
   inject invalid control traffic, network integrity may be compromised.
   Therefore, message authentication is recommended.

   Different such situations may occur, for instance:

   1.  a node generates TC messages, advertising links to non-neighbor
       nodes;

   2.  a node generates TC messages, pretending to be another node;

   3.  a node generates HELLO messages, advertising non-neighbor nodes;

   4.  a node generates HELLO messages, pretending to be another node;

   5.  a node forwards altered control messages;

   6.  a node does not forward control messages;

   7.  a node does not select multipoint relays correctly;

   8.  a node forwards broadcast control messages unaltered, but does
       not forward unicast data traffic;




Clausen, et al.         Expires December 28, 2006              [Page 63]

Internet-Draft                   OLSRv2                        June 2006


   9.  a node "replays" previously recorded control traffic from another
       node.

   Authentication of the originator node for control messages (for
   situations 2, 4 and 5) and on the individual links announced in the
   control messages (for situations 1 and 3) may be used as a
   countermeasure.  However to prevent nodes from repeating old (and
   correctly authenticated) information (situation 9) temporal
   information is required, allowing a node to positively identify such
   delayed messages.

   In general, digital signatures and other required security
   information may be transmitted as a separate OLSRv2 message type,
   thereby allowing that "secured" and "unsecured" nodes can coexist in
   the same network, if desired, or signatures and security information
   may be transmitted within the OLSRv2 HELLO and TC messages, using the
   TLV mechanism.

   Specifically, the authenticity of entire OLSRv2 control messages can
   be established through employing IPsec authentication headers,
   whereas authenticity of individual links (situations 1 and 3) require
   additional security information to be distributed.

   An important consideration is, that all control messages in OLSRv2
   are transmitted either to all nodes in the neighborhood (HELLO
   messages) or broadcast to all nodes in the network (TC messages).

   For example, a control message in OLSRv2 is always a point-to-
   multipoint transmission.  It is therefore important that the
   authentication mechanism employed permits that any receiving node can
   validate the authenticity of a message.  As an analogy, given a block
   of text, signed by a PGP private key, then anyone with the
   corresponding public key can verify the authenticity of the text.

Appendix G.3.  Interaction with External Routing Domains

   OLSRv2 does, through the use of TC messages, provide a basic
   mechanism for injecting external routing information to the OLSRv2
   domain.  Appendix E also specifies that routing information can be
   extracted from the topology table or the routing table of OLSRv2 and,
   potentially, injected into an external domain if the routing protocol
   governing that domain permits.

   Other than as described in Appendix E, when operating nodes,
   connecting OLSRv2 to an external routing domain, care MUST be taken
   not to allow potentially insecure and untrustworthy information to be
   injected from the OLSRv2 domain to external routing domains.  Care
   MUST be taken to validate the correctness of information prior to it



Clausen, et al.         Expires December 28, 2006              [Page 64]

Internet-Draft                   OLSRv2                        June 2006


   being injected as to avoid polluting routing tables with invalid
   information.

   A recommended way of extending connectivity from an existing routing
   domain to an OLSRv2 routed MANET is to assign an IP prefix (under the
   authority of the nodes/gateways connecting the MANET with the exiting
   routing domain) exclusively to the OLSRv2 MANET area, and to
   configure the gateways statically to advertise routes to that IP
   sequence to nodes in the existing routing domain.

Appendix G.4.  Node Identity

   OLSRv2 does not make any assumption about node addresses, other than
   that each node is assumed to have at least one a unique and routable
   IP address for each interface that it has which participates in the
   MANET.



































Clausen, et al.         Expires December 28, 2006              [Page 65]

Internet-Draft                   OLSRv2                        June 2006


Appendix H.  Flow and Congestion Control

   TBD
















































Clausen, et al.         Expires December 28, 2006              [Page 66]

Internet-Draft                   OLSRv2                        June 2006


Appendix I.  Contributors

   This specification is the result of the joint efforts of the
   following contributors -- listed alphabetically.

   o  Cedric Adjih, INRIA, France, <Cedric.Adjih@inria.fr>

   o  Emmanuel Baccelli, Hitachi Labs Europe, France,
      <Emmanuel.Baccelli@inria.fr>

   o  Thomas Heide Clausen, PCRI, France<T.Clausen@computer.org>

   o  Justin Dean, NRL, USA<jdean@itd.nrl.navy.mil>

   o  Christopher Dearlove, BAE Systems, UK,
      <Chris.Dearlove@baesystems.com>

   o  Satoh Hiroki, Hitachi SDL, Japan, <h-satoh@sdl.hitachi.co.jp>

   o  Philippe Jacquet, INRIA, France, <Philippe.Jacquet@inria.fr>

   o  Monden Kazuya, Hitachi SDL, Japan, <monden@sdl.hitachi.co.jp>

   o  Kenichi Mase, Niigata University, Japan, <mase@ie.niigata-u.ac.jp>

   o  Ryuji Wakikawa, KEIO University, Japan, <ryuji@sfc.wide.ad.jp>

























Clausen, et al.         Expires December 28, 2006              [Page 67]

Internet-Draft                   OLSRv2                        June 2006


Appendix J.  Acknowledgements

   The authors would like to acknowledge the team behind OLSRv1,
   specified in RFC3626, including Anis Laouiti, Pascale Minet, Laurent
   Viennot (all at INRIA, France), and Amir Qayuum (Center for Advanced
   Research in Engineering, Pakistan) for their contributions.

   The authors would like to gratefully acknowledge the following people
   for intense technical discussions, early reviews and comments on the
   specification and its components: Li Li (CRC), Louise Lamont (CRC),
   Joe Macker (NRL), Alan Cullen (BAE Systems), Philippe Jacquet
   (INRIA), Khaldoun Al Agha (LRI), Richard Ogier (SRI), Song-Yean Cho
   (Samsung Software Center), Shubhranshu Singh (Samsung AIT) and the
   entire IETF MANET working group.





































Clausen, et al.         Expires December 28, 2006              [Page 68]

Internet-Draft                   OLSRv2                        June 2006


Authors' Addresses

   Thomas Heide Clausen
   LIX, Ecole Polytechnique, France

   Phone: +33 6 6058 9349
   Email: T.Clausen@computer.org
   URI:   http://www.lix.polytechnique.fr/Labo/Thomas.Clausen/


   Christopher M. Dearlove
   BAE Systems Advanced Technology Centre

   Phone: +44 1245 242194
   Email: chris.dearlove@baesystems.com
   URI:   http://www.baesystems.com/ocs/sharedservices/atc/


   Philippe Jacquet
   Project Hipercom, INRIA

   Phone: +33 1 3963 5263
   Email: philippe.jacquet@inria.fr
   URI:   http://hipercom.inria.fr/test/Jacquet.htm


   The OLSRv2 Design Team
   MANET Working Group























Clausen, et al.         Expires December 28, 2006              [Page 69]

Internet-Draft                   OLSRv2                        June 2006


Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.


Disclaimer of Validity

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


Copyright Statement

   Copyright (C) The Internet Society (2006).  This document is subject
   to the rights, licenses and restrictions contained in BCP 78, and
   except as set forth therein, the authors retain all their rights.


Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.




Clausen, et al.         Expires December 28, 2006              [Page 70]


Html markup produced by rfcmarkup 1.109, available from https://tools.ietf.org/tools/rfcmarkup/