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Transmission of IP Packets over Overlay Multilink Network (OMNI) Interfaces
draft-templin-6man-omni-21

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
Authors Fred Templin , Tony Whyman
Last updated 2021-06-03 (Latest revision 2021-06-02)
Replaces draft-templin-6man-omni-interface
Replaced by draft-templin-intarea-omni
RFC stream Independent Submission
Formats
Additional resources
Stream ISE state In ISE Review
Consensus boilerplate Unknown
Document shepherd Eliot Lear
IESG IESG state I-D Exists
Telechat date (None)
Responsible AD (None)
Send notices to rfc-ise@rfc-editor.org
draft-templin-6man-omni-21
Internet-Draft          IPv6 over OMNI Interfaces              June 2021

   [RFC5175]  Haberman, B., Ed. and R. Hinden, "IPv6 Router
              Advertisement Flags Option", RFC 5175,
              DOI 10.17487/RFC5175, March 2008,
              <https://www.rfc-editor.org/info/rfc5175>.

   [RFC5213]  Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
              Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
              RFC 5213, DOI 10.17487/RFC5213, August 2008,
              <https://www.rfc-editor.org/info/rfc5213>.

   [RFC5214]  Templin, F., Gleeson, T., and D. Thaler, "Intra-Site
              Automatic Tunnel Addressing Protocol (ISATAP)", RFC 5214,
              DOI 10.17487/RFC5214, March 2008,
              <https://www.rfc-editor.org/info/rfc5214>.

   [RFC5558]  Templin, F., Ed., "Virtual Enterprise Traversal (VET)",
              RFC 5558, DOI 10.17487/RFC5558, February 2010,
              <https://www.rfc-editor.org/info/rfc5558>.

   [RFC5798]  Nadas, S., Ed., "Virtual Router Redundancy Protocol (VRRP)
              Version 3 for IPv4 and IPv6", RFC 5798,
              DOI 10.17487/RFC5798, March 2010,
              <https://www.rfc-editor.org/info/rfc5798>.

   [RFC5880]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
              (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010,
              <https://www.rfc-editor.org/info/rfc5880>.

   [RFC6081]  Thaler, D., "Teredo Extensions", RFC 6081,
              DOI 10.17487/RFC6081, January 2011,
              <https://www.rfc-editor.org/info/rfc6081>.

   [RFC6221]  Miles, D., Ed., Ooghe, S., Dec, W., Krishnan, S., and A.
              Kavanagh, "Lightweight DHCPv6 Relay Agent", RFC 6221,
              DOI 10.17487/RFC6221, May 2011,
              <https://www.rfc-editor.org/info/rfc6221>.

   [RFC6247]  Eggert, L., "Moving the Undeployed TCP Extensions RFC
              1072, RFC 1106, RFC 1110, RFC 1145, RFC 1146, RFC 1379,
              RFC 1644, and RFC 1693 to Historic Status", RFC 6247,
              DOI 10.17487/RFC6247, May 2011,
              <https://www.rfc-editor.org/info/rfc6247>.

   [RFC6355]  Narten, T. and J. Johnson, "Definition of the UUID-Based
              DHCPv6 Unique Identifier (DUID-UUID)", RFC 6355,
              DOI 10.17487/RFC6355, August 2011,
              <https://www.rfc-editor.org/info/rfc6355>.

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Internet-Draft          IPv6 over OMNI Interfaces              June 2021

   [RFC6438]  Carpenter, B. and S. Amante, "Using the IPv6 Flow Label
              for Equal Cost Multipath Routing and Link Aggregation in
              Tunnels", RFC 6438, DOI 10.17487/RFC6438, November 2011,
              <https://www.rfc-editor.org/info/rfc6438>.

   [RFC6543]  Gundavelli, S., "Reserved IPv6 Interface Identifier for
              Proxy Mobile IPv6", RFC 6543, DOI 10.17487/RFC6543, May
              2012, <https://www.rfc-editor.org/info/rfc6543>.

   [RFC6706]  Templin, F., Ed., "Asymmetric Extended Route Optimization
              (AERO)", RFC 6706, DOI 10.17487/RFC6706, August 2012,
              <https://www.rfc-editor.org/info/rfc6706>.

   [RFC6935]  Eubanks, M., Chimento, P., and M. Westerlund, "IPv6 and
              UDP Checksums for Tunneled Packets", RFC 6935,
              DOI 10.17487/RFC6935, April 2013,
              <https://www.rfc-editor.org/info/rfc6935>.

   [RFC6936]  Fairhurst, G. and M. Westerlund, "Applicability Statement
              for the Use of IPv6 UDP Datagrams with Zero Checksums",
              RFC 6936, DOI 10.17487/RFC6936, April 2013,
              <https://www.rfc-editor.org/info/rfc6936>.

   [RFC6980]  Gont, F., "Security Implications of IPv6 Fragmentation
              with IPv6 Neighbor Discovery", RFC 6980,
              DOI 10.17487/RFC6980, August 2013,
              <https://www.rfc-editor.org/info/rfc6980>.

   [RFC7042]  Eastlake 3rd, D. and J. Abley, "IANA Considerations and
              IETF Protocol and Documentation Usage for IEEE 802
              Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042,
              October 2013, <https://www.rfc-editor.org/info/rfc7042>.

   [RFC7084]  Singh, H., Beebee, W., Donley, C., and B. Stark, "Basic
              Requirements for IPv6 Customer Edge Routers", RFC 7084,
              DOI 10.17487/RFC7084, November 2013,
              <https://www.rfc-editor.org/info/rfc7084>.

   [RFC7323]  Borman, D., Braden, B., Jacobson, V., and R.
              Scheffenegger, Ed., "TCP Extensions for High Performance",
              RFC 7323, DOI 10.17487/RFC7323, September 2014,
              <https://www.rfc-editor.org/info/rfc7323>.

   [RFC7401]  Moskowitz, R., Ed., Heer, T., Jokela, P., and T.
              Henderson, "Host Identity Protocol Version 2 (HIPv2)",
              RFC 7401, DOI 10.17487/RFC7401, April 2015,
              <https://www.rfc-editor.org/info/rfc7401>.

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   [RFC7421]  Carpenter, B., Ed., Chown, T., Gont, F., Jiang, S.,
              Petrescu, A., and A. Yourtchenko, "Analysis of the 64-bit
              Boundary in IPv6 Addressing", RFC 7421,
              DOI 10.17487/RFC7421, January 2015,
              <https://www.rfc-editor.org/info/rfc7421>.

   [RFC7526]  Troan, O. and B. Carpenter, Ed., "Deprecating the Anycast
              Prefix for 6to4 Relay Routers", BCP 196, RFC 7526,
              DOI 10.17487/RFC7526, May 2015,
              <https://www.rfc-editor.org/info/rfc7526>.

   [RFC7542]  DeKok, A., "The Network Access Identifier", RFC 7542,
              DOI 10.17487/RFC7542, May 2015,
              <https://www.rfc-editor.org/info/rfc7542>.

   [RFC7739]  Gont, F., "Security Implications of Predictable Fragment
              Identification Values", RFC 7739, DOI 10.17487/RFC7739,
              February 2016, <https://www.rfc-editor.org/info/rfc7739>.

   [RFC7761]  Fenner, B., Handley, M., Holbrook, H., Kouvelas, I.,
              Parekh, R., Zhang, Z., and L. Zheng, "Protocol Independent
              Multicast - Sparse Mode (PIM-SM): Protocol Specification
              (Revised)", STD 83, RFC 7761, DOI 10.17487/RFC7761, March
              2016, <https://www.rfc-editor.org/info/rfc7761>.

   [RFC7847]  Melia, T., Ed. and S. Gundavelli, Ed., "Logical-Interface
              Support for IP Hosts with Multi-Access Support", RFC 7847,
              DOI 10.17487/RFC7847, May 2016,
              <https://www.rfc-editor.org/info/rfc7847>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8402]  Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
              July 2018, <https://www.rfc-editor.org/info/rfc8402>.

   [RFC8726]  Farrel, A., "How Requests for IANA Action Will Be Handled
              on the Independent Stream", RFC 8726,
              DOI 10.17487/RFC8726, November 2020,
              <https://www.rfc-editor.org/info/rfc8726>.

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   [RFC8754]  Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
              Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
              (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
              <https://www.rfc-editor.org/info/rfc8754>.

   [RFC8892]  Thaler, D. and D. Romascanu, "Guidelines and Registration
              Procedures for Interface Types and Tunnel Types",
              RFC 8892, DOI 10.17487/RFC8892, August 2020,
              <https://www.rfc-editor.org/info/rfc8892>.

   [RFC8899]  Fairhurst, G., Jones, T., Tuexen, M., Ruengeler, I., and
              T. Voelker, "Packetization Layer Path MTU Discovery for
              Datagram Transports", RFC 8899, DOI 10.17487/RFC8899,
              September 2020, <https://www.rfc-editor.org/info/rfc8899>.

   [RFC8900]  Bonica, R., Baker, F., Huston, G., Hinden, R., Troan, O.,
              and F. Gont, "IP Fragmentation Considered Fragile",
              BCP 230, RFC 8900, DOI 10.17487/RFC8900, September 2020,
              <https://www.rfc-editor.org/info/rfc8900>.

   [RFC8981]  Gont, F., Krishnan, S., Narten, T., and R. Draves,
              "Temporary Address Extensions for Stateless Address
              Autoconfiguration in IPv6", RFC 8981,
              DOI 10.17487/RFC8981, February 2021,
              <https://www.rfc-editor.org/info/rfc8981>.

Appendix A.  OAL Checksum Algorithm

   The OAL Checksum Algorithm adopts the 8-bit Fletcher Checksum
   Algorithm specified in Appendix I of [RFC1146] as also analyzed in
   [CKSUM].  [RFC6247] declared [RFC1146] historic for the reason that
   the algorithms had never seen widespread use with TCP, however this
   document adopts the 8-bit Fletcher algorithm for a different purpose.
   Quoting from Appendix I of [RFC1146], the OAL Checksum Algorithm
   proceeds as follows:

      "The 8-bit Fletcher Checksum Algorithm is calculated over a
      sequence of data octets (call them D[1] through D[N]) by
      maintaining 2 unsigned 1's-complement 8-bit accumulators A and B
      whose contents are initially zero, and performing the following
      loop where i ranges from 1 to N:

         A := A + D[i]

         B := B + A

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      It can be shown that at the end of the loop A will contain the
      8-bit 1's complement sum of all octets in the datagram, and that B
      will contain (N)D[1] + (N-1)D[2] + ... + D[N]."

   To calculate the OAL checksum, the above algorithm is applied over
   the N-octet concatenation of the OAL pseudo-header, the encapsulated
   IP packet and the two-octet trailing checksum field initialized to 0.
   Specifically, the algorithm is first applied over the 40 octets of
   the OAL pseudo-header as data octets D[1] through D[40], then
   continues over the entire length of the original IP packet as data
   octets D[41] through D[N-2] and finally concludes with the two
   trailing 0 octets as data octets D[N-1] and D[N].

Appendix B.  VDL Mode 2 Considerations

   ICAO Doc 9776 is the "Technical Manual for VHF Data Link Mode 2"
   (VDLM2) that specifies an essential radio frequency data link service
   for aircraft and ground stations in worldwide civil aviation air
   traffic management.  The VDLM2 link type is "multicast capable"
   [RFC4861], but with considerable differences from common multicast
   links such as Ethernet and IEEE 802.11.

   First, the VDLM2 link data rate is only 31.5Kbps - multiple orders of
   magnitude less than most modern wireless networking gear.  Second,
   due to the low available link bandwidth only VDLM2 ground stations
   (i.e., and not aircraft) are permitted to send broadcasts, and even
   so only as compact layer 2 "beacons".  Third, aircraft employ the
   services of ground stations by performing unicast RS/RA exchanges
   upon receipt of beacons instead of listening for multicast RA
   messages and/or sending multicast RS messages.

   This beacon-oriented unicast RS/RA approach is necessary to conserve
   the already-scarce available link bandwidth.  Moreover, since the
   numbers of beaconing ground stations operating within a given spatial
   range must be kept as sparse as possible, it would not be feasible to
   have different classes of ground stations within the same region
   observing different protocols.  It is therefore highly desirable that
   all ground stations observe a common language of RS/RA as specified
   in this document.

   Note that links of this nature may benefit from compression
   techniques that reduce the bandwidth necessary for conveying the same
   amount of data.  The IETF lpwan working group is considering possible
   alternatives: [https://datatracker.ietf.org/wg/lpwan/documents].

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Appendix C.  MN / AR Isolation Through L2 Address Mapping

   Per [RFC4861], IPv6 ND messages may be sent to either a multicast or
   unicast link-scoped IPv6 destination address.  However, IPv6 ND
   messaging should be coordinated between the MN and AR only without
   invoking other nodes on the *NET.  This implies that MN / AR control
   messaging should be isolated and not overheard by other nodes on the
   link.

   To support MN / AR isolation on some *NET links, ARs can maintain an
   OMNI-specific unicast L2 address ("MSADDR").  For Ethernet-compatible
   *NETs, this specification reserves one Ethernet unicast address TBD3
   (see: Section 25).  For non-Ethernet statically-addressed *NETs,
   MSADDR is reserved per the assigned numbers authority for the *NET
   addressing space.  For still other *NETs, MSADDR may be dynamically
   discovered through other means, e.g., L2 beacons.

   MNs map the L3 addresses of all IPv6 ND messages they send (i.e.,
   both multicast and unicast) to MSADDR instead of to an ordinary
   unicast or multicast L2 address.  In this way, all of the MN's IPv6
   ND messages will be received by ARs that are configured to accept
   packets destined to MSADDR.  Note that multiple ARs on the link could
   be configured to accept packets destined to MSADDR, e.g., as a basis
   for supporting redundancy.

   Therefore, ARs must accept and process packets destined to MSADDR,
   while all other devices must not process packets destined to MSADDR.
   This model has well-established operational experience in Proxy
   Mobile IPv6 (PMIP) [RFC5213][RFC6543].

Appendix D.  Change Log

   << RFC Editor - remove prior to publication >>

   Differences from draft-templin-6man-omni-20 to draft-templin-6man-
   omni-21:

   o  Final editorial review pass resulting in multiple changes.
      Document now submit for final approval (with reference to rfcdiff
      from previous version).

   Differences from draft-templin-6man-omni-19 to draft-templin-6man-
   omni-20:

   o  Final editorial review pass resulting in multiple changes.
      Document now submit for final approval (with reference to rfcdiff
      from previous version).

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   Differences from draft-templin-6man-omni-18 to draft-templin-6man-
   omni-19:

   o  Final editorial review pass resulting in multiple changes.
      Document now submit for final approval (with reference to rfcdiff
      from previous version).

   Differences from draft-templin-6man-omni-17 to draft-templin-6man-
   omni-18:

   o  Final editorial review pass resulting in multiple changes.
      Document now submit for final approval (with reference to rfcdiff
      from previous version).

   Differences from draft-templin-6man-omni-16 to draft-templin-6man-
   omni-17:

   o  Final editorial review pass resulting in multiple changes.
      Document now submit for final approval (with reference to rfcdiff
      from previous version).

   Differences from draft-templin-6man-omni-15 to draft-templin-6man-
   omni-16:

   o  Final editorial review pass resulting in multiple changes.
      Document now submit for final approval.

   Differences from draft-templin-6man-omni-14 to draft-templin-6man-
   omni-15:

   o  Text restructuring to remove ambiguities, eliminate extraneous
      text and improve readability.

   o  Clarified that the OMNI link model is NBMA and that link-scoped
      multicast is through iterative unicast.

   Differences from draft-templin-6man-omni-13 to draft-templin-6man-
   omni-14:

   o  Brought back the optional two-message exchange feature.

   o  Added TCP RST flag and new (OPT, PNG) flags to the OMNI option
      header.

   o  Require the OAL node that initiates the symmetric connection to
      include its (future) receive window size in the initial SYN.

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   o  Require OAL nodes to select new ISS values that are outside of the
      current SND.WND.

   o  Text clarifications for improved readability.

   Differences from draft-templin-6man-omni-12 to draft-templin-6man-
   omni-13:

   o  Complete revision of OAL Identification Window Maintenance section
      to incorporate well-known protocol conventions and terminology.

   Differences from draft-templin-6man-omni-11 to draft-templin-6man-
   omni-12:

   o  Expanded on details of symmetric window synchronization.

   Differences from draft-templin-6man-omni-10 to draft-templin-6man-
   omni-11:

   o  Included an Ordinal Number field in the Compressed Header format
      for non-final fragments

   o  Clarified that the window coordination protocol is based on the
      IPv6 ND connectionless protocol using TCP constructs, and not
      based on the TCP connection-oriented protocol.

   o  Removed unneeded fields from the OMNI option header.

   Differences from draft-templin-6man-omni-09 to draft-templin-6man-
   omni-10:

   o  Fixed sizing considerations for OMNI option fields.

   o  Updated handling of multiple OMNI options in the same IPv6 ND
      message.  Only the first option includes the header, while all
      other options include only sub-options.

   Differences from draft-templin-6man-omni-08 to draft-templin-6man-
   omni-09:

   o  Included reference to RFC3366 and updated section on Fragment
      Retransmission.

   o  Added "ordinal number" marking in Fragment Header reserved field.

   Differences from draft-templin-6man-omni-07 to draft-templin-6man-
   omni-08:

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   o  Included TCP state variables; window scale

   Differences from draft-templin-6man-omni-06 to draft-templin-6man-
   omni-07:

   o  Moved Interface Attributes, Type 1 and Type 2 to historic status.

   o  Incorporated Traffic Selector into Interface Attributes, Type 4.

   Differences from draft-templin-6man-omni-05 to draft-templin-6man-
   omni-06:

   o  Adopted TCP as an OAL packet-based connection-oriented protocol.

   o  Three-Way handshake for establishing symmetric send/receive
      windows

   o  Window length specified, plus "current" and "previous" windows

   o  New appendix on checksum algorithm, with citations changed

   o  Security architecture considerations.

   o  More details on HIP message signatures.

   o  Require firewalls at OAL destinations.

   o  Removed "equal-length" requirement for OAL non-final fragments.

   Differences from draft-templin-6man-omni-04 to draft-templin-6man-
   omni-05:

   o  Change to S/T-omIndex definition.

   Differences from draft-templin-6man-omni-03 to draft-templin-6man-
   omni-04:

   o  Changed reference citations to "draft-templin-6man-aero".

   o  Included introductory description of the "6M's".

   o  Included new OMNI sub-option for PIM-SM.

   Differences from draft-templin-6man-omni-02 to draft-templin-6man-
   omni-03:

   o  Added citation of RFC8726.

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   Differences from draft-templin-6man-omni-01 to draft-templin-6man-
   omni-02:

   o  Updated IANA registration policies for OMNI registries.

   Differences from draft-templin-6man-omni-00 to draft-templin-6man-
   omni-01:

   o  Changed intended document status to Informational, and removed
      documents from "updates" category.

   o  Updated implementation status.

   o  Minor edits to HIP message specifications.

   o  Clarified OAL and *NET IP header field settings during
      encapsulation and re-encapsulation.

   Differences from earlier versions to draft-templin-6man-omni-00:

   o  Established working baseline reference.

Authors' Addresses

   Fred L. Templin (editor)
   The Boeing Company
   P.O. Box 3707
   Seattle, WA  98124
   USA

   Email: fltemplin@acm.org

   Tony Whyman
   MWA Ltd c/o Inmarsat Global Ltd
   99 City Road
   London  EC1Y 1AX
   England

   Email: tony.whyman@mccallumwhyman.com

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