64share-V2                                                     C. Byrne
Internet Draft                                             T-Mobile USA
Intended status: Informational                         November 9, 2020
Expires: May 2021



                                64share-V2
                    draft-byrne-v6ops-64sharev2-00.txt


Abstract

   In a 3GPP wireless network, the IPv6 radio interfaces must be
   provided as an off-link /64 using RA.  This memo updates that
   requirement, through liaison with the 3GPP, to allow any legitimate
   prefix size less than or equal to /64 be allocated from the 3GPP
   network gateway to the UE using RA. This modification allows a UE to
   assign and delegate prefixes to attached and downstream networks.

Status of this Memo

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

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Table of Contents


   1. Introduction...................................................2
   2. Delegating IPv6 Prefixes to a 3GPP UE via Router Advertisements3
   3. Consuming, Assigning, and Delegating the RA Assigned Prefix....3
   4. Security Considerations........................................3
   5. IANA Considerations............................................3
   6. Summary and Conclusions........................................3
   7. Acknowledgments................................................4
   8. References.....................................................4
      8.1. Normative References......................................4
      8.2. Informative References....................................4

   1. Introduction

   3GPP wireless networks assign an IPv6 /64 off-link prefix to each
   user equipment (UE) attachment [RFC 6459].  This has enabled the
   widely deployed sharing of the 3GPP wireless link prefix to hosts on
   an attached LAN [RFC 7278].  This model is limited to a single /64
   and is therefore not fit for anything more than the simplest of
   scenarios.

   While DHCPv6 Prefix Delegation (PD) [RFC 3633] is optionally
   supported in the 3GPP standard for providing larger IPv6 prefix
   allocations to UEs, it has not seen any a commercial deployment in
   3GPP networks.  This memo does not speculate on the challenges of


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   deploying DHCPv6 PD, it simply acknowledges that another way may
   result in quicker and broader deployment of larger more useful IPv6
   allocations.

   2. Delegating IPv6 Prefixes to a 3GPP UE via Router Advertisements

   As described in [RFC 6459], the 3GPP network may only assign a single
   off-link /64 per bearer attachment.  This assignment is passed from
   the gateway to the UE using a router advertisement (RA)[RFC 4861].
   This memo requests the 3GPP to change this requirement to allow any
   prefix size less than or equal to 64 be advertised by the 3GPP
   gateway RA.

   This change allows the UE to be given a prefix such as a /56 using
   RA, which is consider sufficient for a home network.  As wireless
   networks are playing a larger role in delivery home broadband as well
   as other complex network scenarios, the need to deliver greater than
   a single /64 is imperative.

   3. Consuming, Assigning, and Delegating the RA Assigned Prefix

   Once the UE has received the off-link less than 64 bit prefix, it may
   use the prefix in any legitimate manner.  For example, the host
   configuration may have defined configuration rules that state if a
   /56 is received from the 3GPP network, it will assign a /64 to the
   wireless LAN interface, another /64 is to be used for a CLAT [RFC
   6877], and the remainder of addresses will create a pool of prefixes
   that are assigned to downstream DHCPv6 PD clients.

   4. Security Considerations

   TBD

   5. IANA Considerations

   TBD

   6. Summary and Conclusions

   This memo requests that the 3GPP modify its IPv6 assignment
   restrictions to facilitate RA assignment of IPv6 prefixes less than
   or equal to /64.  It also guides UE deployments to use these larger
   allocations of IPv6 addresses to assign and delegate to downstream
   systems.





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   7. Acknowledgments

   TBD.



8. References

8.1. Normative References

   [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
             "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
             DOI 10.17487/RFC4861, September 2007,
             <https://www.rfc-editor.org/info/rfc4861>.

8.2. Informative References

   [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
             Host Configuration Protocol (DHCP) version 6", RFC 3633,
             December 2003, <http://www.rfc-editor.org/info/rfc3633>.

   [RFC6459] Korhonen, J., Soininen, J., Patil, B., Savolainen, T.,
             Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
             Partnership Project (3GPP) Evolved Packet System (EPS)",
             RFC 6459, January 2012, <http://www.rfc-
             editor.org/info/rfc6459>.

   [RFC6877] Mawatari, M., Kawashima, M., and C. Byrne, "464XLAT:
             Combination of Stateful and Stateless Translation",
             RFC 6877, DOI 10.17487/RFC6877, April 2013,
             <https://www.rfc-editor.org/info/rfc6877>.

   [RFC7278] Byrne, C., Drown, D., and A. Vizdal, "Extending an IPv6
             /64 Prefix from a Third Generation Partnership Project
             (3GPP) Mobile Interface to a LAN Link", RFC 7278, June
             2014, <http://www.rfc-editor.org/info/rfc7278>.



Authors' Addresses

   Cameron Byrne
   T-Mobile USA
   Bellevue, WA




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