V6OPS Working Group D. Binet
Internet-Draft M. Boucadair
Intended status: Informational France Telecom
Expires: September 12, 2013 A. Vizdal
Deutsche Telekom AG
C. Byrne
G. Chen
China Mobile
March 11, 2013

Internet Protocol Version 6 (IPv6) Profile for Mobile Devices


This document specifies an IPv6 profile for mobile devices. It lists the set of features a mobile device is to be compliant with to connect to an IPv6-only or dual-stack mobile network. The document identifies also features to ensure IPv4 service continuity over an IPv6-only transport.

Both Hosts and devices with LAN capabilities are in scope.

Status of This Memo

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

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/.

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."

This Internet-Draft will expire on September 12, 2013.

Copyright Notice

Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

Table of Contents

1. Introduction

[RFC3316] lists a set of features to be supported by cellular hosts to connect to 3GPP cellular networks. Since the publication of that document, new functions have been specified within the 3GPP and the IETF whilst others have been updated. Moreover, in the light of recent IPv6 production deployments, additional features to facilitate IPv6-only deployments while accessing IPv4-only service are to be considered.

A detailed overview of IPv6 support in 3GPP architectures is provided in [RFC6459].

This document makes use of the terms defined in [RFC6459].

PREFIX64 denotes an IPv6 prefix used to build IPv4-converted IPv6 addresses [RFC6052].

1.1. Why this document is needed?

IPv6 deployment in mobile networks is the only perennial solution to the exhaustion of IPv4 addresses in those networks. Several mobile operators already deployed IPv6 or are in the pre-deployment phase. One of the major hurdles encountered by mobile operators is the availability of non-broken IPv6 implementation in mobile devices. Some vendors are already proposing some mobile devices with a set of IPv6 features, but the majority of devices are still lacking IPv6 support.

This document specifies an IPv6 profile for mobile devices listing required specifications produced by various SDOs (in particular 3GPP and IETF). The objectives of this effort are:

  1. List in one single document all requirements a mobile device is to comply with to connect to an IPv6 or dual stack mobile network. These requirements cover various network types such as GPRS, EPC or Wi-Fi network.
  2. Help Operators with the detailed device requirement list preparation (to be exchanged with device suppliers). This is also a contribution to harmonize Operators’ requirements towards device vendors.
  3. Vendors to be aware of a minimal set of requirements to allow for IPv6 connectivity and IPv4 service continuity (over an IPv6- only transport).

This document lists the required features while [I-D.ietf-v6ops-rfc3316bis] is doing a good job in identifying issues and explaining how to implement basic IPv6 features in a mobile context. Some of the features discussed in [I-D.ietf-v6ops-rfc3316bis] are also listed in this document as a requirement: the main reason is to collect in one single document a comprehensive list of requirements with the required language.

1.2. Scope

Various types of nodes can be connected to 3GPP networks requiring specific functions. Indeed, a 3GPP network can be used to connect user equipment such as a mobile telephone, a CPE or a machine-to-machine (M2M) device. Because of this diversity of terminals, it is necessary to define a set of IPv6 functionalities valid for any node directly connecting to a 3GPP network. This document describes these functionalities.

This document is structured to initially provide the generic IPv6 requirements which are valid for all nodes, whatever their function or service (e.g., SIP [RFC3261]) capability. The document also contains, dedicated sections covering specific functionalities the specific device types must support (e.g., smartphones, devices providing some LAN functions (mobile CPE or broadband dongles)).

M2M devices profile is out of scope.

The requirements listed below are valid for both 3GPP GPRS and 3GPP EPS access. For EPS, "PDN type" terminology is used instead of "PDP context".

1.3. Special Language

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 RFC 2119 [RFC2119].

This document is not a standard. It uses the normative keywords only for precision.

2. Connectivity Requirements

The cellular host MUST support the IPv6 addressing architecture described in ([RFC4291]). For address representation, [RFC5952] MUST be supported.
The cellular host MUST support both IPv6 and IPv4v6 PDP Contexts.
The cellular host MUST comply with the behavior defined in [TS.23060] [TS.23401] [TS.24008] for requesting a PDP context type. In particular, the cellular host MUST request an IPv6 PDP context if the cellular host is IPv6-only and requesting an IPv4v6 PDP context if the cellular host is dual stack or when the cellular host is not aware of connectivity types requested by devices connected to it (e.g., cellular host with LAN capabilities):

The text above focuses on the specification part which explains the behavior for requesting IPv6-related PDP context(s). Understanding this behavior is important to avoid having broken IPv6 implementations in cellular devices.

The cellular host MUST support the PCO (Protocol Configuration Options) [TS.24008] to retrieve the IPv6 address(es) of the Recursive DNS server(s).
The cellular host MUST support IPv6 aware Traffic Flow Templates (TFT) [TS.24008].
The cellular host MUST support ICMPv6 ([RFC4443]).
The device MUST support the Neighbor Discovery Protocol ([RFC4861] and [RFC5942]).
The cellular host MUST support IPv6 Stateless Address Autoconfiguration ([RFC4862]) apart from the exceptions noted in [TS.23060] (3G) and [TS.23401] (LTE):
The cellular host SHOULD support Router Advertisement Options [RFC6106] for DNS configuration.
The cellular host SHOULD embed a DHCPv6 client [RFC3736].
The cellular host SHOULD support a method to locally construct IPv4-embedded IPv6 addresses [RFC6052]. A method to learn PREFIX64 SHOULD be supported by the cellular host.
The cellular host SHOULD implement the Customer Side Translator (CLAT, [I-D.ietf-v6ops-464xlat]) function which is compliant with [RFC6052][RFC6145][RFC6146].
The cellular device SHOULD embed a DNS64 function [RFC6147].
The cellular host SHOULD support PCP [I-D.ietf-pcp-base].
When the cellular host is dual stack connected, it SHOULD support means to prefer native IPv6 connection over connection established through translation devices (e.g., NAT44 and NAT64).
The cellular host SHOULD support Happy Eyeballs procedure defined in [RFC6555].
The cellular host SHOULD NOT perform Duplicate Address Detection (DAD) for these Global IPv6 addresses (as the GGSN or PDN-GW must not configure any IPv6 addresses using the prefix allocated to the cellular host). Refer to Section 4 for DAD considerations on the LAN interface when the 3GPP connection is shared.
The cellular device MAY embed a BIH function [RFC6535] facilitating the communication between an IPv4 application and an IPv6 server.

2.1. WiFi Connectivity

It is increasingly common for cellular hosts have a Wi-Fi interface in addition to their cellular interface. These hosts are likely to be connected to private or public hotspots. Below are listed some generic requirements:

IPv6 MUST be supported on the Wi-Fi interface. In particular, IPv6-only connectivity MUST be supported over the Wi-Fi interface.
DHCPv6 client SHOULD be supported on Wi-Fi interface ([RFC3736]).
Wi-Fi interface SHOULD support Router Advertisement Options for DNS configuration ([RFC6106]). If the device receives the DNS information in several channels for the same interface, the following preference order MUST be followed:
  1. RA
  2. DHCPv6

3. Advanced Requirements

The cellular host MUST support Path MTU discovery ([RFC1981]). If the MTU used by cellular hosts is larger than 1280 bytes, they can rely on Path MTU discovery function to discover the real path MTU.
The cellular host SHOULD support the Privacy Extensions for Stateless Address Autoconfiguration in IPv6 ([RFC4941]).
The cellular host SHOULD support ROHC for IPv6 ([RFC5795]).
The cellular host SHOULD support IPv6 Router Advertisement Flags Options ([RFC5175]).
The cellular host SHOULD support Router Advertisement extension for communicating default router preferences and more-specific routes as described in [RFC4191].

4. Cellular Devices with LAN Capabilities

This section focuses on cellular devices (e.g., CPE, smartphones or dongles with tethering features) which provide IP connectivity to other devices connected to them. In such case, all connected devices are sharing the same GPRS, UMTS or EPS connection. In addition to the generic requirements listed in Section 2, these cellular devices have to meet the requirements listed below.

The cellular device MUST support Prefix Delegation capabilities [RFC3633] and MUST support Prefix Exclude Option for DHCPv6-based Prefix Delegation as defined in [RFC6603]. Particularly, it MUST behave as a Requesting Router.
The cellular device MUST be compliant with the CPE requirements specified in [RFC6204].
Prefix delegation which allows to allocate a shorter prefix to a cellular host is only available since 3GPP Release 10. For deployments requiring to share the same /64 prefix, the cellular device SHOULD support [I-D.ietf-v6ops-64share] to enable sharing a /64 prefix between the 3GPP interface towards the GGSN (WAN interface) and the LAN interfaces.
The cellular device SHOULD support the Customer Side Translator (CLAT) [I-D.ietf-v6ops-464xlat].
If a RA MTU is advertised from the 3GPP network, the cellular device SHOULD relay that upstream MTU information to the downstream attached LAN devices in RA.

5. APIs & Applications

Name resolution libraries MUST support both IPv4 and IPv6.
Applications MUST be independent of the underlying IP address family.
Applications using URIs MUST follow [RFC3986]. For example, SIP applications MUST follow the correction defined in [RFC5954].

6. Security Considerations

The security considerations identified in [RFC3316] are to be taken into account.

If the cellular device provides LAN features, it SHOULD be compliant with the security requirements specified in [RFC6092].

7. IANA Considerations

This document does not require any action from IANA.

8. Acknowledgements

Many thanks to H. Soliman, H. Singh, L. Colliti, T. Lemon, B. Sarikaya, J. Korhonen, M. Mawatari, M. Abrahamsson, P. Vickers, V. Kuarsingh and J. Woodyatt for the discussion in the v6ops mailing list.

9. References

9.1. Normative References

[RFC1981] McCann, J., Deering, S. and J. Mogul, "Path MTU Discovery for IP version 6", RFC 1981, DOI 10.17487/RFC1981, August 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, DOI 10.17487/RFC3261, June 2002.
[RFC3596] Thomson, S., Huitema, C., Ksinant, V. and M. Souissi, "DNS Extensions to Support IP Version 6", RFC 3596, DOI 10.17487/RFC3596, October 2003.
[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, DOI 10.17487/RFC3633, December 2003.
[RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol (DHCP) Service for IPv6", RFC 3736, DOI 10.17487/RFC3736, April 2004.
[RFC3986] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005.
[RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and More-Specific Routes", RFC 4191, DOI 10.17487/RFC4191, November 2005.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, DOI 10.17487/RFC4291, February 2006.
[RFC4443] Conta, A., Deering, S. and M. Gupta, "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", RFC 4443, DOI 10.17487/RFC4443, March 2006.
[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.
[RFC4862] Thomson, S., Narten, T. and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, DOI 10.17487/RFC4862, September 2007.
[RFC4941] Narten, T., Draves, R. and S. Krishnan, "Privacy Extensions for Stateless Address Autoconfiguration in IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007.
[RFC5175] Haberman, B. and R. Hinden, "IPv6 Router Advertisement Flags Option", RFC 5175, DOI 10.17487/RFC5175, March 2008.
[RFC5795] Sandlund, K., Pelletier, G. and L-E. Jonsson, "The RObust Header Compression (ROHC) Framework", RFC 5795, DOI 10.17487/RFC5795, March 2010.
[RFC5942] Singh, H., Beebee, W. and E. Nordmark, "IPv6 Subnet Model: The Relationship between Links and Subnet Prefixes", RFC 5942, DOI 10.17487/RFC5942, July 2010.
[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6 Address Text Representation", RFC 5952, DOI 10.17487/RFC5952, August 2010.
[RFC5954] Gurbani, V., Carpenter, B. and B. Tate, "Essential Correction for IPv6 ABNF and URI Comparison in RFC 3261", RFC 5954, DOI 10.17487/RFC5954, August 2010.
[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M. and X. Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, DOI 10.17487/RFC6052, October 2010.
[RFC6106] Jeong, J., Park, S., Beloeil, L. and S. Madanapalli, "IPv6 Router Advertisement Options for DNS Configuration", RFC 6106, DOI 10.17487/RFC6106, November 2010.
[RFC6145] Li, X., Bao, C. and F. Baker, "IP/ICMP Translation Algorithm", RFC 6145, DOI 10.17487/RFC6145, April 2011.
[RFC6146] Bagnulo, M., Matthews, P. and I. van Beijnum, "Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers", RFC 6146, DOI 10.17487/RFC6146, April 2011.
[RFC6147] Bagnulo, M., Sullivan, A., Matthews, P. and I. van Beijnum, "DNS64: DNS Extensions for Network Address Translation from IPv6 Clients to IPv4 Servers", RFC 6147, DOI 10.17487/RFC6147, April 2011.
[RFC6535] Huang, B., Deng, H. and T. Savolainen, "Dual-Stack Hosts Using "Bump-in-the-Host" (BIH)", RFC 6535, DOI 10.17487/RFC6535, February 2012.
[RFC6555] Wing, D. and A. Yourtchenko, "Happy Eyeballs: Success with Dual-Stack Hosts", RFC 6555, DOI 10.17487/RFC6555, April 2012.
[RFC6603] Korhonen, J., Savolainen, T., Krishnan, S. and O. Troan, "Prefix Exclude Option for DHCPv6-based Prefix Delegation", RFC 6603, DOI 10.17487/RFC6603, May 2012.
[RFC6724] Thaler, D., Draves, R., Matsumoto, A. and T. Chown, "Default Address Selection for Internet Protocol Version 6 (IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012.

9.2. Informative References

[I-D.ietf-behave-nat64-discovery-heuristic] Savolainen, T., Korhonen, J. and D. Wing, "Discovery of the IPv6 Prefix Used for IPv6 Address Synthesis", Internet-Draft draft-ietf-behave-nat64-discovery-heuristic-17, April 2013.
[I-D.ietf-mif-happy-eyeballs-extension] Chen, G., Williams, C., Wing, D. and A. Yourtchenko, "Happy Eyeballs Extension for Multiple Interfaces", Internet-Draft draft-ietf-mif-happy-eyeballs-extension-09, February 2016.
[I-D.ietf-pcp-base] Wing, D., Cheshire, S., Boucadair, M., Penno, R. and P. Selkirk, "Port Control Protocol (PCP)", Internet-Draft draft-ietf-pcp-base-29, November 2012.
[I-D.ietf-pcp-nat64-prefix64] Boucadair, M., "Learning NAT64 PREFIX64s using Port Control Protocol (PCP)", Internet-Draft draft-ietf-pcp-nat64-prefix64-06, February 2014.
[I-D.ietf-v6ops-464xlat] Mawatari, M., Kawashima, M. and C. Byrne, "464XLAT: Combination of Stateful and Stateless Translation", Internet-Draft draft-ietf-v6ops-464xlat-10, February 2013.
[I-D.ietf-v6ops-64share] Byrne, C., Drown, D. and V. Ales, "Extending an IPv6 /64 Prefix from a 3GPP Mobile Interface to a LAN link", Internet-Draft draft-ietf-v6ops-64share-10, April 2014.
[I-D.ietf-v6ops-rfc3316bis] Korhonen, J., Arkko, J., Savolainen, T. and S. Krishnan, "IPv6 for 3GPP Cellular Hosts", Internet-Draft draft-ietf-v6ops-rfc3316bis-06, September 2013.
[RFC3314] Wasserman, M., "Recommendations for IPv6 in Third Generation Partnership Project (3GPP) Standards", RFC 3314, DOI 10.17487/RFC3314, September 2002.
[RFC3316] Arkko, J., Kuijpers, G., Soliman, H., Loughney, J. and J. Wiljakka, "Internet Protocol Version 6 (IPv6) for Some Second and Third Generation Cellular Hosts", RFC 3316, DOI 10.17487/RFC3316, April 2003.
[RFC6092] Woodyatt, J., "Recommended Simple Security Capabilities in Customer Premises Equipment (CPE) for Providing Residential IPv6 Internet Service", RFC 6092, DOI 10.17487/RFC6092, January 2011.
[RFC6204] Singh, H., Beebee, W., Donley, C., Stark, B. and O. Troan, "Basic Requirements for IPv6 Customer Edge Routers", RFC 6204, DOI 10.17487/RFC6204, April 2011.
[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, DOI 10.17487/RFC6459, January 2012.
[TS.23060] 3GPP, , "General Packet Radio Service (GPRS); Service description; Stage 2", September 2011.
[TS.23401] 3GPP, , "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access", September 2011.
[TS.24008] 3GPP, , "Mobile radio interface Layer 3 specification; Core network protocols; Stage 3", June 2011.

Authors' Addresses

David Binet France Telecom Rennes, France EMail: david.binet@orange.com
Mohamed Boucadair France Telecom Rennes, 35000 France EMail: mohamed.boucadair@orange.com
Ales Vizdal Deutsche Telekom AG EMail: ales.vizdal@t-mobile.cz
Cameron Byrne T-Mobile USA EMail: Cameron.Byrne@T-Mobile.com
Gang Chen China Mobile EMail: phdgang@gmail.com