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

Versions: 00 01 02 03 04 05 06 07 08 09 10 11 RFC 5121

Network Working Group                                   Basavaraj. Patil
Internet-Draft                                                     Nokia
Intended status: Standards Track                              Frank. Xia
Expires: April 17, 2007                                 Behcet. Sarikaya
                                                              Huawei USA
                                                       Syam. Madanapalli
                                                               LogicaCMG
                                                         JinHyeock. Choi
                                                             Samsung AIT
                                                        October 14, 2006


         IPv6 Over IPv6 Convergence sublayer in WiMAX Networks
                  draft-ietf-16ng-ipv6-over-ipv6cs-00

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 April 17, 2007.

Copyright Notice

   Copyright (C) The Internet Society (2006).








Patil, et al.            Expires April 17, 2007                 [Page 1]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


Abstract

   The WiMAX forum is defining the network architecture which enables
   Internet connectivity to mobile stations and IP hosts via the
   802.16d/e radio interface.  This document specifies the addressing
   and operation of IPv6 for hosts served by a WiMAX network.  It
   recommends the assignment of a unique prefix to each host and allow
   the host to use multiple identifiers within that prefix, including
   support for randomly generated identifiers.  IPv6 operation in WiMAX
   networks as explained in this document is based entirely on existing
   IETF specifications.  The solution entailed herein is recommended for
   adoption by the WiMAX forum for IPv6 over the IPv6 convergence
   sublayer.


Table of Contents

   1.  Conventions used in this document  . . . . . . . . . . . . . .  3
   2.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  5
   4.  IEEE 802.16d/e convergence sublayer support for IPv6 . . . . .  6
   5.  WiMAX network architecture . . . . . . . . . . . . . . . . . .  7
   6.  IPv6 link in WiMAX . . . . . . . . . . . . . . . . . . . . . .  9
     6.1.  IPv6 link establishment  . . . . . . . . . . . . . . . . .  9
     6.2.  Maximum transmission unit  . . . . . . . . . . . . . . . .  9
   7.  IPv6 prefix assignment . . . . . . . . . . . . . . . . . . . . 11
   8.  Router Discovery . . . . . . . . . . . . . . . . . . . . . . . 12
     8.1.  Router Solictation . . . . . . . . . . . . . . . . . . . . 12
     8.2.  Router Advertisement . . . . . . . . . . . . . . . . . . . 12
     8.3.  Router lifetime and periodic router advertisements . . . . 12
   9.  IPv6 addressing for hosts  . . . . . . . . . . . . . . . . . . 13
     9.1.  Interface Identifier . . . . . . . . . . . . . . . . . . . 13
     9.2.  Duplicate address detection  . . . . . . . . . . . . . . . 13
     9.3.  Stateless address autoconfiguration  . . . . . . . . . . . 13
     9.4.  Stateful address autoconfiguration . . . . . . . . . . . . 13
   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 14
   11. Security Considerations  . . . . . . . . . . . . . . . . . . . 15
   12. Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 16
   13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
     13.1. Normative References . . . . . . . . . . . . . . . . . . . 17
     13.2. Informative References . . . . . . . . . . . . . . . . . . 18
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
   Intellectual Property and Copyright Statements . . . . . . . . . . 20








Patil, et al.            Expires April 17, 2007                 [Page 2]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


1.  Conventions used in this document

   In this document, the key words "MUST", "MUST NOT", "REQUIRED",
   "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
   RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as
   described in BCP 14, RFC 2119 [RFC2119] and indicate requirement
   levels for compliant implementations.












































Patil, et al.            Expires April 17, 2007                 [Page 3]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


2.  Introduction

   IEEE 802.16d/e is the air interface specification underlying the
   WiMAX forums network architecture specification.  The 802.16d/e
   [802.16e] specification includes the Phy and MAC details.  This
   document specifies the operation of IPv6 over 802.16d/e in the
   context of the WiMAX network architecture.  Specifically it is
   limited to the operation of IPv6 over the IPv6 convergence sublayer.
   The IPv6 convergence sublayer is a part of the 802.16e MAC.  The IPv6
   link between the mobile station (MS) and the access router (AR) is
   considered as a point-to-point link.  Assignment of a unique prefix
   per MS is recommended in this document.  The document provides a
   brief overview of the WiMAX network architecture at a high level and
   describes the addressing and, transmission and receiving of IPv6
   packets, by an MS.




































Patil, et al.            Expires April 17, 2007                 [Page 4]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


3.  Terminology

   The terminology is based on the definitions used in the network
   architecture specified by the WiMAX forum.

   BS - The WiMAX Base Station (BS) is a logical entity that embodies a
   full instance of the WiMAX MAC and PHY in compliance with the IEEE
   802.16 suite of applicable standards.  It provides the layer 1/2
   connectivity between the network and the MS.

   MS - The mobile station is an IPv6 host that connects to the WiMAX
   network via an 802.16d/e module.

   Transport Connection - 802.16 MAC is connection oriented.  Several
   types of connections are defined and these include broadcast, unicast
   and multicast.  Each connection is uniquely identified by a 16 bit
   connection identifier (CID).  A transport connection is a unicast
   connection intended for user traffic.  A transport connection is
   identified by an uplink and downlink CID.  The scope of the transport
   connection is between the MS and the BS.

   Access Service Network (ASN) - The ASN is defined as a complete set
   of network functions needed to provide radio access to a WiMAX
   subscriber.  The ASN is the access network to which the MS attaches.
   The IPv6 access router is an entity within the ASN.

   Access Router (AR) - The Access router is the 1st hop default IPv6
   router from the perspective of the MS.  The AR is an entity that
   exists within the scope of an ASN.






















Patil, et al.            Expires April 17, 2007                 [Page 5]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


4.  IEEE 802.16d/e convergence sublayer support for IPv6

   IEEE 802.16d/e has specified multiple convergence sublayers (CS) in
   the MAC.  The convergence sublayers and MAC specifications are
   available in [802.16e].  IPv6 can be implemented in two ways:

   1.  Over the IPv6 convergence sublayer or

   2.  Over Ethernet (which runs over Ethernet CS).

   The figure below shows the options for IPv6 implementation in WiMAX:


           --------------            ---------------
           |  IPv6      |            |   IPV6      |
           --------------            ---------------
           |   IPv6 CS  |            | Ethernet    |
           | .......... |            ---------------
           |    MAC     |            | Ethernet CS |
           --------------            | ........... |
           |    PHY     |            |   MAC       |
           --------------            ---------------
             IPv6 over IPv6 CS       |   PHY       |
                                     ---------------
                                      IPv6 over Ethernet

               Figure 1: IPv6 over IPv6 CS and over Ethernet

   WiMAX forum has chosen IP CS as the default CS to be supported for IP
   connectivity.  The scope of this document is limited to IPv6
   operation over IPv6 CS only.




















Patil, et al.            Expires April 17, 2007                 [Page 6]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


5.  WiMAX network architecture

   The WiMAX network architecture consists of the Access Service Network
   (ASN) and the Connectivity Service Network (CSN).  The ASN is the
   access network which includes the BS and the AR in addition to other
   functions such as AAA, Mobile IP Foreign agent, Paging controller,
   Location Register etc.  The CSN is the entity that provides
   connectivity to the Internet and includes functions such as Mobile IP
   Home agent and AAA.  The figure below shows the WiMAX reference
   model:



                        -------------------
                        | ----      ASN   |                    |----|
         ----           | |BS|\ R6 -------|    |---------|     | CSN|
         |MS|-----R1----| ---- \---|ASN-GW| R3 |  CSN    | R5  |    |
         ----           |  |R8  /--|------|----|         |-----|Home|
                        | ---- /          |    |  visited|     | NSP|
                        | |BS|/           |    |   NSP   |     |    |
                        | ----            |    |---------|     |    |
                        |       NAP       |         \          |----|
                        -------------------          \---|        /
                                |                        |       /
                                |                     (--|------/----)
                                |R4                  (                )
                                |                   (      ASP network )
                            ---------                ( or Internet    )
                            |  ASN  |                 (              )
                            ---------                   (----------)



                  Figure 2: WiMAX Network reference model

   Three different types of ASN realizations called profiles are defined
   by the architecture.  ASNs of profile types A and C include BS' and
   ASN-gateway(s) which are connected to each other via an R6 interface.
   An ASN of profile type B is one in which the functionality of the BS
   and other ASN functions are merged together.  No ASN-GW is
   specifically defined in a profile B ASN.  However all the functions
   of an ASN such as the MIP4 FA, AAA, AR exist within the scope of an
   ASN.  The absence of the R6 interface is also a profile B specific
   characteristic.  The MS at the IPv6 layer is associated with the AR
   in the ASN.  The AR may be a function of the ASN-GW in the case of
   profiles A and C and is a function in the ASN in the case of profile
   B. When the BS and the AR are separate entities and linked via the R6
   interface, IPv6 packets between the BS and the AR are carried over a



Patil, et al.            Expires April 17, 2007                 [Page 7]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


   GRE tunnel.  The granularity of the GRE tunnel can be on a per flow
   basis, per MS basis or on a BS basis.  The protocol stack in WiMAX
   for IPv6 is shown below:


   |-------|
   | App   |- - - - - - - - - - - - - - - - - - - - - - - -(to app peer)
   |       |
   |-------|                                   /------      -------
   |       |                                  / IPv6 |      |     |
   | IPv6  |- - - - - - - - - - - - - - - -  /       |      |     |-->
   |       |      ---------------    -------/        |      | IPv6|
   |-------|      |    \Relay/  |    |      |        |- - - |     |
   |       |      |     \   /   |    | GRE  |        |      |     |
   |       |      |      \ /GRE | -  |      |        |      |     |
   |       |- - - |       |-----|    |------|        |      |     |
   | IPv6CS|      |IPv6CS | IP  | -  | IP   |        |      |     |
   | ..... |      |...... |-----|    |------|--------|      |-----|
   |  MAC  |      | MAC   | L2  | -  | L2   |  L2    |- - - | L2  |
   |-------|      |------ |-----|    |----- |--------|      |-----|
   |  PHY  |- - - | PHY   | L1  | -  | L1   |  L1    |- - - | L1  |
    --------      ---------------    -----------------      -------

      MS             BS                   AR/ASN-GW          CSN Rtr



                      Figure 3: WiMAX protocol stack

   As can be seen from the protocol stack description, the IPv6 end-
   points are constituted in the MS and the AR.  The BS provides lower
   layer connectivity for the IPv6 link.



















Patil, et al.            Expires April 17, 2007                 [Page 8]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


6.  IPv6 link in WiMAX

   The MS and the AR are connected via a combination of :

   1.  The transport connection which is identified by a Connection
       Identifier (CID) over the air interface, i.e the MS and BS and,

   2.  A GRE tunnel between the BS and AR which transports the IPv6
       packets

   From an IPv6 perspective the MS and the AR are connected by a point-
   to-point link.  The transport connection over the air interface and
   the GRE tunnel between the BS and AR create a tunnel at the layer
   below IPv6.  Each link has only an MS and an AR.  Each MS belongs to
   a different link.  No two MSs belong to the same link.  A different
   prefix should be assigned to a different link.  This link is fully
   consistent with a standard IP link, without exception and conforms
   with the definition of a point-to-point link in RFC2461 [RFC2461].

6.1.  IPv6 link establishment

   The mobile station performs initial network entry as specified in
   802.16e [Ref80216].  On succesful completion of the network entry
   procedure the ASN gateway/AR triggers the establishment of the
   initial service flow (ISF) for IPv6 towards the MS.  The ISF is a GRE
   tunnel between the ASN-GW/AR and the BS.  The BS in turn requests the
   MS to establish a transport connection over the air interface.  The
   end result is a transport connection over the air interface for
   carrying IPv6 packets and a GRE tunnel between the BS and AR for
   relaying the IPv6 packets.  On succesful completion of the
   establishment of the ISF, IPv6 packets can be sent and received
   between the MS and AR.  The ISF enables the MS to communicate with
   the AR for host configuration procedures.  After the establishment of
   the ISF, the AR can send a router advertisement to the MS.  An MS can
   establish multiple service flows with different QoS characteristics.
   The ISF can be considered as the primary service flow.

6.2.  Maximum transmission unit

   The WiMAX forum [WMF] has specified the SDU size as 1522 octets.
   Hence the IPv6 path MTU can be 1500 octets.  However because of the
   overhead of the GRE tunnel used to transport IPv6 packets between the
   BS and AR and the 6 byte MAC header over the air interface, using a
   value of 1500 would result in fragmentation of packets.  It is
   recommended that the default MTU for IPv6 be set to 1400 octets for
   the MS.  Note that the 1522 octet specification is a WiMAX forum
   specification and not the size of the SDU that can be transmitted
   over 802.16d/e, which is higher.  RFC2461 [RFC2461] recommends that



Patil, et al.            Expires April 17, 2007                 [Page 9]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


   IPv6 nodes implement Path MTU discovery.  In such cases the default
   value can be over-ridden.  Additionally if the 802.16d/e MAC layer
   can provide an indication of the MTU size to be used, the MS can use
   that as the default MTU.















































Patil, et al.            Expires April 17, 2007                [Page 10]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


7.  IPv6 prefix assignment

   Each MS can be considered to be on a separate subnet as a result of
   the point-to-point cconnection.  While the MS can establish multiple
   service flows that map to corresponding transport connections over
   the air interface, the ISF and any other service flows established
   for IPv6 traffic should be treated as a single subnet.  A CPE type of
   device which serves multiple IPv6 hosts, may be the end point of the
   connection.  Hence one or more /64 prefixes should be assigned to an
   ISF.  The prefixes are advertised with the on-link (L-bit) flag set
   so that MSs may not make any asumption about the existence of on-link
   neighbors.







































Patil, et al.            Expires April 17, 2007                [Page 11]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


8.  Router Discovery

8.1.  Router Solictation

   On completion of the establishment of the IPv6 ISF, the MS may send a
   router solicitation message to solicit a Router Advertisement message
   from the AR to acquire necessary information as specified in RFC2461
   [RFC2461].  An MS that is network attached may also send router
   solicitations at any time.

8.2.  Router Advertisement

   The AR should send a number of router advertisements as soon as the
   IPv6 ISF is established to the MS.  The AR may send unsolicited
   router advertisements periodically as specified in RFC2461 [RFC2461].
   However to conserve the battery lifetime of hosts and to conserve
   radio resources over the air interface, unsolicited router
   advertisement transmission are not recommended.

8.3.  Router lifetime and periodic router advertisements

   The router lifetime should be set to a large value, preferably in
   hours. 802.16d/e hosts have the capability to transition to an Idle
   mode in which case the radio link between the BS and MS is torn down.
   Paging is required in case the network needs to deliver packets to
   the MS.  In order to avoid waking a mobile which is in Idle mode and
   consuming resources on the air interface, the interval between
   periodic router advertisements should be set quite high.  The
   MaxRtrAdvInterval should be configurable to a value which is greater
   than 1800 seconds.





















Patil, et al.            Expires April 17, 2007                [Page 12]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


9.  IPv6 addressing for hosts

   The addressing scheme for IPv6 hosts in WiMAX follows the IETFs
   recommendation for hosts specified in RFC 4294.  The IPv6 node
   requirements RFC RFC4294 [RFC4294] specifies a set of RFCs that are
   applicable for addressing.

9.1.  Interface Identifier

   The MS has a 48-bit MAC address as specified in 802.16e [802.16e].
   This MAC address is used to generate the 64 bit interface identifier
   which is used by the MS for address autoconfiguration.  The IID is
   generated by the MS as specified in RFC2464 [RFC2464].  For addresses
   that are based on privacy extensions, the MS may generate random IIDs
   as specified in RFC3041 [RFC3041].

9.2.  Duplicate address detection

   DAD is performed as per RFC2461 [RFC2461] and, RFC2462 [RFC2462].

9.3.  Stateless address autoconfiguration

   If the L-bit and A-bit in the prefix information option (PIO) are set
   the MS performs stateless address autoconfiguration as per RFC 2461,
   2462.  The AR in the ASN is the default router that advertises a
   unique /64 prefix (or prefixes) that is used by the MS to configure
   an address.

9.4.  Stateful address autoconfiguration

   The Stateful Address Autoconfiguration is invoked if the M-flag is
   set in the Router Advertisement.  Obtaining the IPv6 address through
   stateful address autoconfiguration method is specified in the RFC3315
   [RFC3315].

















Patil, et al.            Expires April 17, 2007                [Page 13]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


10.  IANA Considerations

   This draft does not require any actions from IANA.
















































Patil, et al.            Expires April 17, 2007                [Page 14]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


11.  Security Considerations

   This document does not introduce any new vulnerabilities to IPv6
   specifications or operation as a result of the 802.16d/e air
   interface or the WiMAX network architecture.














































Patil, et al.            Expires April 17, 2007                [Page 15]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


12.  Acknowledgments

   TBD.
















































Patil, et al.            Expires April 17, 2007                [Page 16]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


13.  References

13.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement  Levels", RFC 2119, March 1997,
              <ftp://ftp.isi.edu/in-notes/rfc2119>.

   [RFC2461]  Narten, T., Nordmark, E., and W. Simpson, "Neighbor
              Discovery for IP Version 6 (IPv6)", RFC 2461,
              December 1998, <ftp://ftp.isi.edu/in-notes/rfc2461>.

   [RFC2462]  Thomson, S. and T. Narten, "IPv6 Stateless Address
              Autoconfiguration", RFC 2462, December 1998,
              <ftp://ftp.isi.edu/in-notes/rfc2462>.

   [RFC2464]  Crawford, M., "Transmission of IPv6 Packets over Ethernet
              Networks", RFC 2464, December 1998,
              <ftp://ftp.isi.edu/in-notes/rfc2464>.

   [RFC3041]  Narten, T. and R. Draves, "Privacy Extensions for
              Stateless Address Autoconfiguration in IPv6", RFC 3041,
              January 2001, <ftp://ftp.isi.edu/in-notes/rfc3041>.

   [RFC3314]  Wasserman, Ed., M., "Recommendations for IPv6 in Third
              Generation Partnership Project (3GPP) Standards",
              RFC 3314, September 2002,
              <ftp://ftp.isi.edu/in-notes/rfc3314>.

   [RFC3315]  Droms, Ed., R., Bound, J., Volz, B., Lemon, T., Perkins,
              C., and M. Carney, "Dynamic Host Configuration Protocol
              for IPv6 (DHCPv6)", RFC 3315, July 2003,
              <ftp://ftp.isi.edu/in-notes/rfc3315>.

   [RFC3756]  Nikander, P., Kempf, J., and E.  Nordmark, "IPv6 Neighbor
              Discovery (ND) Trust Models and Threats", RFC 3756,
              May 2004, <ftp://ftp.isi.edu/in-notes/rfc3756 >.

   [RFC4294]  Loughney, Ed., J., "IPv6 Node requirements", RFC 4294,
              April 2006, <ftp://ftp.isi.edu/in-notes/rfc4294>.

   [RFC4921]  Hinden, R. and S.  Deering, "IP Version 6 Addressing
              Architecture", RFC 4921, February  2006,
              <ftp://ftp.isi.edu/in-notes/rfc4291>.







Patil, et al.            Expires April 17, 2007                [Page 17]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


13.2.  Informative References

   [802.16e]  "IEEE Std 802.16e: IEEE Standard for Local and
              metropolitan area networks, Amendment for Physical and
              Medium Access Control Layers for Combined Fixed and Mobile
              Operation in Licensed Bands", October 2005.

   [WMF]      "http://www.wimaxforum.org".

   [WiMAXArch]
              "WiMAX End-to-End Network Systems Architecture
              http://www.wimaxforum.org/technology/documents",
              August 2006.






































Patil, et al.            Expires April 17, 2007                [Page 18]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


Authors' Addresses

   Basavaraj Patil
   Nokia
   6000 Connection Drive
   Irving, TX  75039
   USA

   Email: basavaraj.patil@nokia.com


   Frank Xia
   Huawei USA
   1700 Alma Dr. Suite 100
   Plano, TX  75075

   Email: xiayangsong@huawei.com


   Behcet Sarikaya
   Huawei USA
   1700 Alma Dr. Suite 100
   Plano, TX  75075

   Email: sarikaya@ieee.org


   Syam Madanapalli
   LogicaCMG
   125 Yemlur P.O.
   Off Airport Road
   Bangalore, India  560037

   Email: smadanapalli@gmail.com


   JinHyeock Choi
   Samsung AIT
   Networking Technology Lab
   P.O.Box 111
   Suwon, Korea  440-600

   Email: jinchoe@samsung.com








Patil, et al.            Expires April 17, 2007                [Page 19]

Internet-Draft         IPv6 over IPv6 CS in WiMAX           October 2006


Full 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.

   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.


Intellectual Property

   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.


Acknowledgment

   Funding for the RFC Editor function is provided by the IETF
   Administrative Support Activity (IASA).





Patil, et al.            Expires April 17, 2007                [Page 20]


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