One document matched: draft-lee-ndp-ieee802.16-00.txt





Network Working Group                                           J-C. Lee
Internet-Draft                                                      ETRI
Expires: April 18, 2006                                         Y-H. Han
                                                             Samsung AIT
                                                               M-K. Shin
                                                                    ETRI
                                                               H-J. Jang
                                                             Samsung AIT
                                                                H-J. Kim
                                                                    ETRI
                                                        October 15, 2005


            Considerations of NDP over IEEE 802.16 Networks
                      draft-lee-ndp-ieee802.16-00

Status of this Memo

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   This Internet-Draft will expire on April 18, 2006.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   IEEE 802.16 issued standards for the new PHY and MAC for providing



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   broadband wireless access network.  It is characterized by very high
   data rates and wider range of which technologies are different from
   existing wireless access technologies such as IEEE 802.11 or 3G.
   Accordingly, the use of IPv6 over IEEE 802.16 network is currently
   undefined.  There are several issues to be considered in deploying
   IPv6 over IEEE 802.16 network.  Among them, this document will
   describe issues related to neighbor discovery protocol (NDP) over
   IEEE 802.16 networks.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Scope of this Document . . . . . . . . . . . . . . . . . .  3
     1.2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  3
     1.3.  Problem Statements . . . . . . . . . . . . . . . . . . . .  4
       1.3.1.  Issues regarding ND protocol itself  . . . . . . . . .  4
       1.3.2.  Architectural and Operational Issues . . . . . . . . .  6
     1.4.  Specification of Requirements  . . . . . . . . . . . . . .  8
   2.  Protocols  . . . . . . . . . . . . . . . . . . . . . . . . . .  9
     2.1.  Case 4: BS and router in one box + Prefix to subnet  . . .  9
       2.1.1.  Addresses  . . . . . . . . . . . . . . . . . . . . . .  9
       2.1.2.  Address Autoconfiguration  . . . . . . . . . . . . . . 11
       2.1.3.  Router and Prefix Discovery  . . . . . . . . . . . . . 11
       2.1.4.  Redirect function  . . . . . . . . . . . . . . . . . . 12
   3.  The use of ND messages . . . . . . . . . . . . . . . . . . . . 13
     3.1.  Router Solicitation Message  . . . . . . . . . . . . . . . 13
     3.2.  Router Advertisement Message . . . . . . . . . . . . . . . 13
     3.3.  Neighbor Solicitation Message  . . . . . . . . . . . . . . 14
     3.4.  Neighbor Advertisement Message . . . . . . . . . . . . . . 15
     3.5.  Redirect Message . . . . . . . . . . . . . . . . . . . . . 15
   4.  Conceptual Model of a Host . . . . . . . . . . . . . . . . . . 17
     4.1.  Conceptual Data Structures . . . . . . . . . . . . . . . . 17
   5.  Summary Matrix . . . . . . . . . . . . . . . . . . . . . . . . 18
     5.1.  Case 4: BS and router in one box + Prefix to subnet  . . . 18
   6.  Secuirty Considerations  . . . . . . . . . . . . . . . . . . . 19
   7.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 20
     7.1.  Normative References . . . . . . . . . . . . . . . . . . . 20
     7.2.  Informative References . . . . . . . . . . . . . . . . . . 20
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21
   Intellectual Property and Copyright Statements . . . . . . . . . . 23










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1.  Introduction

   The IEEE802.11 network has driven the revolution of wireless
   communication, but as the more people use it, more of its limitations
   like short range or lack of mobility support have been revealed.
   Compared with IEEE802.11 network, IEEE802.16 supports enhanced
   features like wider range and mobility.  Thus, it is expected that
   IEEE802.16 network would be the next step of IEEE802.11 network.

   The IEEE802.11 MAC protocol is almost same as the IEEE802.3 protocol
   with the exception of being able to be used over an air medium.
   Thus, most of the existing layer 3 protocols can be used without any
   modification.  The structure of IEEE802.16 protocol is, however, much
   different from the IEEE802.11 protocol.  Therefore, it is needed to
   consider if IPv6 runs well over IEEE802.16 networks.

   There are several issues to be considered in deploying IPv6 over
   IEEE802.16 network [I-D.shin-ipv6-ieee802.16].  Among them, this
   document will describe issues about the Neighbor Discovery Protocol
   [RFC2461].

1.1.  Scope of this Document

   The considerations described in this document are only applied to the
   subnet composed of BS and MS(s) attached to that BS over the
   IEEE802.16 network.

   We are considering two BS deployment cases and two addressing cases
   each, but only one scenario that adopts BS integrated with router
   function and allocates a same prefix to all MS(s) attached to one BS
   would be considered in this version of draft.

1.2.  Terminology

   802.16 subnet:

      The subnet composed of MS(s) attached to the same BS.  This
      terminology is only used in this document.

   SS:

      Subscriber Station.  A general equipment set providing
      connectivity between subscriber equipment and a BS.

   MS:






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      Mobile Station.  A station in the mobile service intended to be
      used while in motion or during halts at unspecified points.  A
      mobile station (MS) is always a subscriber station (SS) unless
      specifically excepted otherwise in this document.

   BS:

      Base Station.  A generalized equipment set providing connectivity,
      management and control of MS connection.  A unidirectional mapping
      between BS and MS medium access control (MAC) peers for the
      purpose of transporting a service flow's traffic.  Connections are
      identified by a connection identifier (CID).  All traffic is
      carried on a connection.

   CID:

      Connection IDentifier.  A 16-bit value that identifies a
      connection to equivalent peers in the MAC of the BS and the MS.
      It maps to a service flow identifier (SFID), which also defines
      QoS parameters of the service flow associated with that
      connection.

   NS:

      Neighbor Solicitation message

   NA:

      Neighbor Advertisement message

   RS:

      Router Solicitation message

   RA:

      Router Advertisement message

   and all other terminologies declared in [RFC2461]

1.3.  Problem Statements

1.3.1.  Issues regarding ND protocol itself

   Sending to and Receiving from multicast address:

      1.  The 802.16 MAC header doesn't include a MAC address, so we
          can't send to or receive from multicast address as the way how



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          802.3 and 802.11 do.

      2.  How to join multicast addresses (all-nodes multicast address,
          solicited-node multicast address) required for DAD? or is
          there any way to send or receive multicast packet without
          joining multicast address?

   Address autoconfiguration:

      1.  Creation of link-local address (requires DAD): basically, IPv6
          node creates link-local address for use on a single link.
          Link-local addresses are designed to be used for addressing on
          a single link for purposes such as automatic address
          configuration, neighbor discovery, or when no routers are
          present.  In order to create link-local addresses, DAD should
          be done to guarantee the uniqueness of the link-local
          addresses in a link.  This DAD MUST take place on all unicast
          addresses, regardless of whether they are obtained through
          stateful, stateless or manual configuration [RFC2462].  The
          problem in processing DAD is that the procedure for DAD uses
          NS message sent to solicited-node multicast address and NA
          message sent to all-node multicast address.

      2.  Creation of global scope address (requires DAD): IPv6 host can
          create its global-scope addresses by appending an interface
          identifier to a prefix obtained from RA message.  Even in this
          case, DAD should be done with the same reason as link-local
          address case.

   Conceptual sending algorithm:

      1.  Address Resolution (solicited-node multicast address): When
          sending a packet to a destination, a node uses a combination
          of the Destination Cache, the Prefix List, and the Default
          Router List to determine the IP address of the appropriate
          next hop, an operation known as "next-hop determination".
          Once the IP address of the next-hop node is known, the sender
          examines the Neighbor Cache for link-layer information about
          that neighbor.  If no entry exists, the sender creates new
          one, and then initiates Address Resolution.  For multicast-
          capable interfaces Address Resolution consists of sending a NS
          message destined for solicited-node multicast address and
          waiting for a NA message.  There are two problems with this
          issues.  The one is whether Address Resolution is needed or
          not over 802.16 network and the other is if Address Resolution
          is needed, how we send NS message destined for solicited-node
          multicast address.




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      2.  Neighbor Unreachability Detection: whenever an IPv6 node
          accesses its Neighbor Cache entry while transmitting a unicast
          packet, the sender checks Neighbor Unreachability Detection
          related information according to NUD algorithm.  If there is
          no need to do Address Resolution, NUD is not needed.

   Router and Prefix discovery:

      1.  Sending Router Solicitation message to all-router multicast
          address: Router Discovery is used to locate neighboring
          routers as well as learn prefixes and configuration parameters
          related to address autoconfiguration.  This procedure consists
          of sending RS message to All-routers multicast address and
          receiving RA message.  The problem is how we send RS message
          destined for all-routers multicast address.

      2.  Set the 'L' bit in Prefix Information option or not? (on-link
          determination): The Prefix Information option has 'L' bit
          indicating this prefix can be used for on-link determination.
          As what mentioned before we have two policies on allocating
          prefixes to the MS(s).  The determination of setting 'L' bit
          is dependent on this policy.

   Redirect function

      Is it needed in 802.16 network environment?

1.3.2.  Architectural and Operational Issues

   We consider two types of the Base Station deployment mode and two
   policies on how we allocate prefixes to the Mobile Station.

   IEEE 802.16 Base Station Deployment Modes

      We describe two possible deployment architectures of IEEE 802.16
      network.  Figure 1 and 2 show the two cases.

      1.  Router separation from BS: In Figure 1, routers are located
          separated with IEEE 802.16 BSs.  In this case, IEEE 802.16 BSs
          have only MAC and PHY layers without router function.  A
          router and several BSs form an IPv6 subnet.  BSs may not have
          IPv6 stack.  But, for management and configuration purpose,
          IPv6 stack will be loaded to them.  A simple or complex
          network equipments may constitute the underlying wired network
          between BSs and router.  In a subnet, therefore, there are
          always two underlying links including IEEE 802.16 wireless
          link between SS and BS.  In this case, the methods of IPv6
          adoption to IEEE 802.16 may depend on the underlying network



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          architecture between BSs and router.

               /-------------------------------------\
              |           Backbend Network            |
               \-------------------------------------/
                     |                         |
               /-----------\             /-----------\
              |   Router1   |           |   Router2   |
               \-----------/             \-----------/
               /  /  |  \  \             /  /  |  \  \
              /  /   |   \  \           /  /   |   \  \
             /   |   |   |   \         /   |   |   |   \
           BS1 BS2  BS3  BS4 BS5     BS6 BS7  BS8  BS9 BS10

          Figure 1.  IEEE 802.16 deployment architecture with BS and
          Router in separated boxes

      2.  BS and router in one box: Figure 2 represents an alternative
          IEEE 802.16 network deployment where a BS is integrated with a
          router, composing one box in view of implementation.  A subnet
          consists of only single router and single BS.  In this case,
          many IPv6 functionalities can be implemented without much
          consideration about the underlying network implementation.
          Only IEEE 802.16 link will be taken into consideration for
          IPv6 adoption.

                       /------------------\
                      |  Backbend Network  |
                       \------------------/
                           /          \
                          /            \
                         /              \
                    ---------        ---------
                   | Router1 |      | Router2 |
                   | BS1     |      | BS2     |
                    ---------        ---------

          Figure 2.  IEEE 802.16 deployment architecture with BS and
          Router in one box.

   IPv6 ND Prefix Allocation Policies

      There are two possible addressing schemes as follows.

      1.  Prefix to SS: [RFC3314] recommends that a given prefix should
          be assigned to only one primary PDP context so that 3GPP
          terminals are allowed to generate multiple IPv6 address using
          the prefix without the concerns of address confliction.  This



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          recommendation can be also applied to IEEE 802.16 network
          system if it is reasonable to the given usage scenario.  In
          such case, many IPv6 functionalities can be implemented
          without difficulty.

      2.  Prefix to Subnet: Different usage scenario such as 'Hot zone'
          would not allow [RFC3314] recommendation because of the
          compatibility with the existing IPv6 devices.  In this case,
          there will be more issues for adopting IPv6 to IEEE 802.16. (*
          hot zone: an area served by one BS, similar meaning to Hotspot
          in 802.11)

   As a result of above combinations, we can consider the following four
   cases for the scenarios of IPv6 adoption to IEEE 802.16 networks.

     +--+---------------------------+------------------+
     |  |         Deployment        | Addressing       |
     +--+---------------------------+------------------+
     | 1| Router separation from BS | Prefix to SS     |
     +--+---------------------------+------------------+
     | 2| Router separation from BS | Prefix to subnet |
     +--+---------------------------+------------------+
     | 3| BS and router in one box  | Prefix to SS     |
     +--+---------------------------+------------------+
     | 4| BS and router in one box  | Prefix to subnet |
     +--+---------------------------+------------------+



   *** Among above cases we will only consider case 4 in this version of
   draft.

1.4.  Specification of Requirements

   In this document, several words are used to signify the requirements
   of the specification.  These words are often capitalized.  The key
   words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
   "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document
   are to be interpreted as described in [RFC2119].












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2.  Protocols

2.1.  Case 4: BS and router in one box + Prefix to subnet

2.1.1.  Addresses

2.1.1.1.  link-local address

   Basically, the procedure to create link-local address follows
   [RFC2462]. 802.16 interface also has 48bits MAC address as other
   802.x family [IEEE802.16].  Therefore, this 48bits MAC address of
   802.16 interface can be used for making interface identifier.

   Duplicate Address Detection:

      Usually the link between MS and BS resembles a point-to-point
      link, hence if BS allocates different prefix to each MS there is
      no need to do DAD.  But if BS allocates unique prefix to MS(s)
      belong to 802.16 subnet, DAD should be done.  This case will be
      described in Section 2.1.2.1 later.

2.1.1.2.  Multicast address

   ND has several multicast addresses used for its service, but 802.16
   MAC header doesn't include MAC address, and thus this makes it harder
   to deliver and receive ND multicast packet.

   In 802.3, a corresponding MAC address to the each link-local
   multicast address [RFC2464] is maintained and the layer 2 of each
   node can recognize the multicast packets.  Thus, the delivery of the
   multicast packets is done in a distributed manner, but 802.16 does
   not manage such MAC address for the multicast, so the multicasting
   needs to be handled centrally.

   In spite of this limitation, we can use ND service without big
   modification of ND protocol by using the characteristics of 802.16
   network.

   all-nodes multicast address (link-scoped)

      All IPv6 nodes which have unicast address should join this
      multicast address.  There are two cases to send packets to all-
      nodes multicast destination; the one is to send Unsolicited Router
      Advertisement (RA) message to MS(s) and the other is to send
      Unsolicited Neighbor Advertisement (NA) message to the adjacent
      neighbor.





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      Unsolicited RA message: The BS knows MS(s) list attached to
         itself, hence it can send Unsolicited Router Advertisement
         message to MS(s) in a unicast manner.

      Unsolicited NA message: This case could be happen in case that
         link-layer address of a node is changed. *** Needs further
         study... ***

   solicited-node multicast address (link-scoped)

      All IPv6 nodes which have unicast address should join the
      corresponding multicast address.  This address is used for address
      resolution, but usually there is no need to do address resolution
      over 802.16 network in scenario 4, because the next hop of MS is
      always BS.  But there might be some other cases under
      consideration.

   all-routers multicast address (link-scoped)

      This address is used in Router Solicitation message.  The MS can
      send this message to the adjacent router without support of
      multicast because its only neighbor is BS.

   To support the multicast communication, the BS can manage the
   multicast group and handle the delivery in a central manner.  When
   the BS receives the multicast packets, it can apply the selective
   decision to optimize the airlink resources based on the type of
   multicast packets.

   1.  Some types of multicast traffic may be filtered off and be
       dropped by the BS.

   2.  Some types of multicast traffic such as all-nodes multicast may
       be delivered in a unicast manner to all MSs.

   3.  Some types of traffic such as solicited-node or all-routers
       multicast may be delivered in a unicast manner to the some of
       nodes (its members).

   4.  Some types of traffic may be forwarded to a specific node.

   5.  Some types of traffic may be delivered by using a shared CIDs.

   In case of 1), for example, the BS can drop the NS for DAD, which
   will be mention in detail in Section 2.1.2.1.  In case of 2), the BS
   knows MS list attached to itself, hence it can send Unsolicited RA/NA
   to MS(s) by using basic connection allocated to each MS.  For 3), it
   is necessary for the BS to manage each multicast membership.  In case



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   of 4), if the BS can predict the respondent of the multicast packet
   based on the collected information during network (re)entry or
   through some ways, it may forward the multicast packet to the
   specific node.  For 5), the BS can allocate one or more shared
   Connection IDs (CIDs) across all or some MSs, which enables the BS to
   send only a single copy of the packet and all the members of a single
   multicast group can receive it.  In addition to the membership
   knowledge, the BS needs to define the several kinds of CIDs, and be
   able to map the multicast addresses to the corresponding 802.16 CIDs.
   This approach seems to be similar to [RFC2464].

   The BS may use the mix of 1)~5) for the efficiency of air resources.
   For instance, it can use the approaches of 1), 4) and 5) together.
   However, how to implement the assignment of CIDs and the mapping of
   CIDs depends on the BS implementation and is out of scope of this
   document.

2.1.1.3.  Anycast address

   Same as the unicast case.

2.1.2.  Address Autoconfiguration

   The IPv6 host can create link-local unicast address and global-scope
   unicast address in a stateless manner [RFC2462].  Before completing
   address autoconfiguration procedure in Section 2.1 scenario, the IPv6
   host must do DAD to check uniqueness of address.  In this scenario,
   DAD operates as follows.

2.1.2.1.  Duplicate Address Detection (DAD)

   There might be various implementation techniques for DAD
   implementation over 802.16 networks.  When the BS has the list of all
   MS's IP addresses on that link, it can check whether the target
   address in NS is unique or not.  If unique, it may be filtered off as
   described 1. of Section 2.1.1.2, otherwise the BS may forward the
   packets.

   o  As described in Section 2.1.1.2 before, MS can't send NS message
      in a multicast manner.  Instead, the MS sends NS message to BS
      directly.

   o  The BS acts in a manner descried Section 2.1.1.2.

2.1.3.  Router and Prefix Discovery

   Mainly described in Section 2.1.1.2.




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2.1.3.1.  Unsolicited Router Advertisement

   The BS would send Unsolicited RA through interface(s) whose
   AdvSendAdvertisements flag is set TRUE.  This case is also described
   in Section 2.1.1.2.

2.1.4.  Redirect function

   Redirect message shall not be used since MS's next-hop is always BS
   and there is no better choice.









































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3.  The use of ND messages

3.1.  Router Solicitation Message

   IP fields:

      Source address

         ip address assigned to sending interface or unspecified
         address(::)

      Destination address

         all-router multicast address (ff02::2, link-local scope)

   Valid options:

      Source link-layer address

         "The link-layer address of the sender, if known.  MUST NOT be
         included if the Source Address is the unspecified address.
         Otherwise it SHOULD be included on link layers that have
         addresses."  [RFC2461]

         A 802.16 interface has 48bits MAC address, but it is not be
         used in sending or receiving packets except for initialization
         process.  Therefore, this option will not be included.

3.2.  Router Advertisement Message

   The transmission of periodic RAs may not be proper in 802.16 networks
   in view of resource efficiency.  When the MS is attached to link, the
   BS may begin to transmit RAs.  Once the configurable number of RAs is
   sent, the BS may not send more RAs to limit the multicast packets.
   The BS can reply with the RA only in response to RS.

   IP fields:

      Source address

         link-local address assigned to the interface from which this
         message is sent.

      Destination address







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         source address of an invoking router solicitation message or
         all-nodes multicast address(ff02::1, link-local scope)

   ICMP fields:

      Router Lifetime

         "...0 indicates that the router is not a default router and
         SHOULD NOT appear on the default router list..."[RFC2461].  BS
         always acts as default router of MS, hence this field should
         not be set 0.

   Possible options:

      Prefix Information

         In cases that adopt IPv6 ND Prefix Allocation Policy 2, each MS
         comprising 802.16 subnet with same prefix advertised by BS as
         other MS(s) is not on-link with each other.  Therefore set 'L'
         bit off.

3.3.  Neighbor Solicitation Message

   IP fields:

      Source address

         address assigned to the interface from which this message is
         sent or unspecified address (::, in case of DAD)

      Destination address

         solicited-node multicast address (ff02:0:0:0:0:1:ffxx:xxxx,
         link-local scope, in case of address resolution) or target
         address (in case of DAD)

   Possible options:

      Source link-layer address

         "...Otherwise, on link layers that have addresses this option
         MUST be included in multicast solicitations and SHOULD be
         included in unicast solicitations."  [RFC2461].  Does not
         include this option with same reason as Section 3.1.







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3.4.  Neighbor Advertisement Message

   neighbor solicitation messages shall be discarded by BS except if it
   is part of NUD.

   IP fields:

      Source address

         address assigned to the interface from which the advertisement
         is sent.

      Destination address

         for solicited advertisements:

         - source address of an invoking neighbor solicitation

         - all-nodes multicast address (if the source address of
         solicitation message is ::)

         for unsolicited advertisement:

         - all-nodes multicast address (ff02::1, link-local scope)

   Possible options:

      Target link-layer address

         "...This option MUST be included on link layers that have
         addresses when responding to multicast
         solicitations..."[RFC2461].  Does not include this option with
         same reason as Section 3.1 and the next hop of MS is always BS,
         hence this option is meaningless except for Unsolicited
         Neighbor Advertisement.

3.5.  Redirect Message

   This message shall not be used because MS's next-hop is always BS and
   there is no better choice.

   IP fields:

      Source address







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         link-local address assigned to the interface from which this
         message is sent.

      Destination address

         source address of the packet that triggered the redirect.













































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4.  Conceptual Model of a Host

4.1.  Conceptual Data Structures

   Neighbor Cache:

      Usually the MS has neighbor caches, but it might be empty as
      described in Section 2.1.1.2.  This also means that there is no
      need to do NUD.  If the MS should do address resolution by some
      other reason, its next hop would be BS and the neighbor cache
      entry would be filled with the MAC address of the BS.  In this
      case, MS would do NUD.

      Even if there are neighbor caches, it would not be used in sending
      procedure.

   Destination Cache: No special issue.

   Prefix List: No special issue.

   Default Router List: No special issue.






























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5.  Summary Matrix

5.1.  Case 4: BS and router in one box + Prefix to subnet

   +--------+-----------+--------+--------+---------+--------+---+---+
   |        |  Router   |Address |        |         |        |   |   |
   |        |& Prefix   | Auto-  |Address | Next-hop| Packet |   |   |
   |        |& Parameter|Config- |Resolut-|Determin-|Transmi-|NUD|DAD|
   |        |discovery  |uration |ion     |ation    |ssion   |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |   RS   |    O      |   O    |        |         |        |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |   RA   |    O      |   O    |        |         |        |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |   NS   |           |        |  X(O)  |         |        | O | O |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |   NA   |           |        |  X(O)  |         |        | O | O |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |Redirect|           |        |        |         |        |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |Neighbor|           |        |        |         |        |   |   |
   |cache   |           |        |        |         |   O    |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |Destina-|           |        |        |         |        |   |   |
   |tion    |           |        |        |    O    |   O    |   |   |
   |cache   |           |        |        |         |        |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |Prefix  |           |        |        |         |        |   |   |
   |List    |           |        |        |    O    |        |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |Default |           |        |        |         |        |   |   |
   |Router  |           |        |        |    O    |   O    |   |   |
   |List    |           |        |        |         |        |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |  DAD   |           |   O    |        |         |        |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+
   |  NUD   |           |        |        |         |  X(O)  |   |   |
   +--------+-----------+--------+--------+---------+--------+---+---+

   o  Axis X: Operations.

   o  Axis Y: Messages, Data Structures, and Operations used by
      operations.

   o  O : a Message or Data Structure is used.

   o  X(O): Basically a Message or Data Structure is not used, but used
      under special condition.



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6.  Secuirty Considerations

   Until now there is no special security consideration found for these
   issues and most of the security considerations might follow
   [RFC2461].














































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7.  References

7.1.  Normative References

   [RFC2461]  Narten, T., Nordmark, E., and W. Simpson, "Neighbor
              Discovery for IP Version 6 (IPv6)", RFC 2461,
              December 1998.

   [RFC2462]  Thomson, S. and T. Narten, "IPv6 Stateless Address
              Autoconfiguration", RFC 2462, December 1998.

   [RFC2472]  Haskin, D. and E. Allen, "IP Version 6 over PPP",
              RFC 2472, December 1998.

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

   [RFC3314]  Wasserman, M., "Recommendations for IPv6 in Third
              Generation Partnership Project (3GPP) Standards",
              RFC 3314, September 2002.

   [RFC2464]  Crawford, M., "Transmission of IPv6 Packets over Ethernet
              Networks", RFC 2464, December 1998.

   [IEEE802.16]
              "IEEE 802.16-2004, IEEE standard for Local and
              metropolitan area networks,  Part 16:Air Interface for
              fixed broadband wireless access systems", October 2004.

7.2.  Informative References

   [I-D.shin-ipv6-ieee802.16]
              Shin, M., "Scenarios and Considerations of IPv6 in IEEE
              802.16 Networks", draft-shin-ipv6-ieee802.16-01 (work in
              progress), October 2005.
















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Authors' Addresses

   Joo-Chul Lee
   ETRI
   161 Gajeong-dong Yuseong-gu
   Daejeon, 305-350
   Korea

   Fax:   +82 42 861 5404
   Email: rune@etri.re.kr


   Youn-Hee Han
   Samsung AIT
   P.O. Box 111
   Suwon 440-600
   Korea

   Fax:
   Email: yh21.han@samsung.com


   Myung-Ki Shin
   ETRI
   161 Gajeong-dong Yuseong-gu
   Daejeon, 305-350
   Korea

   Fax:   +82 42 861 5404
   Email: mkshin@pec.etri.re.kr


   Hee-Jin Jang
   Samsung AIT
   P.O. Box 111
   Suwon
   Korea

   Fax:   +82 31 280 9569
   Email: heejin.jang@samsung.com











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   Hyoung-Jun Kim
   ETRI
   161 Gajeong-dong Yuseong-gu
   Daejeon, 305-350
   Korea

   Fax:   +82 42 861 5404
   Email: khj@etri.re.kr











































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PAFTECH AB 2003-20262026-04-24 01:57:47