RFC7849

From RFC-Wiki

Independent Submission D. Binet Request for Comments: 7849 M. Boucadair Category: Informational Orange ISSN: 2070-1721 A. Vizdal

                                                 Deutsche Telekom AG
                                                             G. Chen
                                                        China Mobile
                                                          N. Heatley
                                                                  EE
                                                         R. Chandler
                                                     eircom | meteor
                                                          D. Michaud
                                               Rogers Communications
                                                            D. Lopez
                                                      Telefonica I+D
                                                         W. Haeffner
                                                            Vodafone
                                                            May 2016
            An IPv6 Profile for 3GPP Mobile Devices

Abstract

This document defines a profile that is a superset of the connection to IPv6 cellular networks defined in the IPv6 for Third Generation Partnership Project (3GPP) Cellular Hosts document. This document defines a profile that is a superset of the connections to IPv6 cellular networks defined in "IPv6 for Third Generation Partnership Project (3GPP) Cellular Hosts" (RFC 7066).

Both mobile hosts and mobile devices with the capability to share their 3GPP mobile connectivity are in scope.

IESG Note

The consensus-based IETF description of IPv6 functionality for cellular hosts is described in RFC 7066.

Status of This Memo

This document is not an Internet Standards Track specification; it is published for informational purposes.

This is a contribution to the RFC Series, independently of any other RFC stream. The RFC Editor has chosen to publish this document at its discretion and makes no statement about its value for implementation or deployment. Documents approved for publication by the RFC Editor are not a candidate for any level of Internet Standard; see Section 2 of RFC 5741.

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7849.

Copyright Notice

Copyright (c) 2016 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.

3. Recommendations for Cellular Devices with LAN Capabilities . 11

Introduction

IPv6 deployment in 3GPP mobile networks is the only viable solution to the exhaustion of IPv4 addresses in those networks. Several mobile operators have already deployed IPv6 RFC2460 or are in the pre-deployment phase. One of the major hurdles as perceived by some mobile operators is the lack of availability of working IPv6 implementation in mobile devices (e.g., Section 3.3 of [OECD]).

RFC7066 lists a set of features to be supported by cellular hosts to connect to 3GPP mobile networks. In the light of recent IPv6 production deployments, additional features to facilitate IPv6-only deployments while accessing IPv4-only services should be considered.

This document fills this void. Concretely, this document lists means to ensure IPv4 service over an IPv6-only connectivity given the adoption rate of this model by mobile operators. Those operators require that no service degradation is experienced by customers serviced with an IPv6-only model compared to the level of service of customers with legacy IPv4-only devices.

This document defines an IPv6 profile for mobile devices listing specifications produced by various Standards Developing Organizations (including 3GPP, IETF, and the Global System for Mobile Communications Association (GSMA)). The objectives of this effort are as follows:

1. List in one single document a comprehensive list of IPv6 features

   for a mobile device, including both IPv6-only and dual-stack
   mobile deployment contexts.  These features cover various packet
   core architectures such as General Packet Radio Service (GPRS) or
   Evolved Packet Core (EPC).

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. Inform vendors of a set of features to allow for IPv6

   connectivity and IPv4 service continuity (over an IPv6-only
   transport).

The recommendations do not include 3GPP release details. For more information on the 3GPP release details, the reader may refer to Section 6.2 of RFC6459. More details can be found at [R3GPP].

Some of the features listed in this profile document could require that dedicated functions be activated at the network side. It is out of scope of this document to list these network-side functions.

A detailed overview of IPv6 support in 3GPP architectures is provided in RFC6459. IPv6-only considerations in mobile networks are further discussed in RFC6342.

This document is organized as follows:

o Section 2 lists generic recommendations, including functionalities

  to provide IPv4 service over an IPv6-only connectivity.

o Section 3 enumerates a set of recommendations for cellular devices

  with Local Area Network (LAN) capabilities (e.g., Customer Edge
  (CE) routers with cellular access link, dongles with tethering
  features).

o Section 4 identifies a set of advanced recommendations to fulfill

  requirements of critical services such as VoLTE (Voice over LTE).

Terminology

This document makes use of the terms defined in RFC6459. In addition, the following terms are used:

o 3GPP cellular host (or "cellular host" for short): denotes a 3GPP

  device that can be connected to 3GPP mobile networks.

o 3GPP cellular device (or "cellular device" for short): refers to a

  cellular host that supports the capability to share its 3GPP
  mobile connectivity.

o IPv4 service continuity: denotes the features used to provide

  access to IPv4-only services to customers serviced with an
  IPv6-only connectivity.  A typical example of IPv4 service
  continuity technique is Network Address and Protocol Translation
  from IPv6 Clients to IPv4 Servers (NAT64) RFC6146.

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

Scope

A 3GPP mobile network can be used to connect various User Equipment (UE) such as a mobile telephone or a CE router. 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 mobile network. This document describes these functionalities.

The machine-to-machine (M2M) devices profile is out of scope.

This document is structured to provide the generic IPv6 recommendations that are valid for all nodes, whatever their function (e.g., host or CE router) or service (e.g., Session Initiation Protocol (SIP) RFC3261) capability. The document also contains sections covering specific functionalities for devices providing some LAN functions (e.g., mobile CE router or broadband dongles).

The recommendations listed below are valid for both 3GPP GPRS and 3GPP Evolved Packet System (EPS). For EPS, the term "PDN-Connection" is used instead of PDP-Context. Other non-3GPP accesses [TS.23402] are out of scope of this document.

This profile is a superset of that of the IPv6 profile for 3GPP Cellular Hosts RFC7066, which is in turn a superset of IPv6 Node Requirements RFC6434. It targets cellular nodes, including GPRS and EPC, that require features to ensure IPv4 service delivery over an IPv6-only transport in addition to the base IPv6 service. Moreover, this profile also covers cellular CE routers that are used in various mobile broadband deployments. Recommendations inspired from real deployment experiences (e.g., roaming) are included in this profile. Also, this profile sketches recommendations for the sake of deterministic behaviors of cellular devices when the same configuration information is received over several channels.

For conflicting recommendations in RFC7066 and RFC6434 (e.g., Neighbor Discovery Protocol), this profile adheres to RFC7066. Indeed, the support of Neighbor Discovery Protocol is mandatory in 3GPP cellular environment as it is the only way to convey an IPv6 prefix towards the 3GPP cellular device. In particular, Maximum Transmission Unit (MTU) communication via Router Advertisement (RA) must be supported since many 3GPP networks do not have a standard MTU setting.

This profile uses a stronger language for the support of Prefix Delegation compared to RFC7066. The main motivation is that cellular networks are more and more perceived as an alternative to fixed networks for home IP-based services delivery; especially with the advent of smartphones and 3GPP data dongles. There is a need for

an efficient mechanism to assign larger prefixes to cellular hosts so that each LAN segment can get its own /64 prefix and multi-link subnet issues to be avoided. The support of this functionality in both cellular and fixed networks is key for fixed-mobile convergence.

The use of address-family-dependent Application Programming Interfaces (APIs) or hard-coded IPv4 address literals may lead to broken applications when IPv6 connectivity is in use. As such, means to minimize broken applications when the cellular host is attached to an IPv6-only network should be encouraged. Particularly, (1) name resolution libraries (e.g., RFC3596) must support both IPv4 and IPv6; (2) applications must be independent of the underlying IP address family; and (3) applications relying upon Uniform Resource Identifiers (URIs) must follow RFC3986 and its updates. Note, some IETF specifications (e.g., SIP RFC3261) contains broken IPv6 Augmented Backus-Naur Form (ABNF) and rules to compare URIs with embedded IPv6 addresses; fixes (e.g., RFC5954) must be used instead.

The recommendations included in each section are listed in a priority order.

This document is not a standard, and conformance with it is not required in order to claim conformance with IETF standards for IPv6. Compliance with this profile does not require the support of all enclosed items. Obviously, the support of the full set of features may not be required in some deployment contexts. However, the authors believe that not supporting relevant features included in this profile (e.g., Customer-Side Translator (CLAT) RFC6877) may lead to a degraded level of service.

Connectivity Recommendations

This section identifies the main connectivity recommendations to be followed by a cellular host to attach to a network using IPv6 in addition to what is defined in RFC6434 and RFC7066. Both dual- stack and IPv6-only deployment models are considered. IPv4 service continuity features are listed in this section because these are critical for operators with an IPv6-only deployment model. These recommendations apply also for cellular devices (see Section 3).

C_REC#1: In order to allow each operator to select their own

         strategy regarding IPv6 introduction, the cellular host
         must support both IPv6 and IPv4v6 PDP-Contexts [TS.23060].
         IPv4, IPv6, or IPv4v6 PDP-Context request acceptance
         depends on the cellular network configuration.

C_REC#2: The cellular host must comply with the behavior defined in

         [TS.23060], [TS.23401], and [TS.24008] for requesting a
         PDP-Context type.
         In particular, the cellular host must request by default an
         IPv6 PDP-Context if the cellular host is IPv6-only and
         request 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., a cellular host with LAN capabilities as discussed
         in Section 3):
         *  If the requested IPv4v6 PDP-Context is not supported by
            the network but IPv4 and IPv6 PDP types are allowed,
            then the cellular host will be configured with an IPv4
            address or an IPv6 prefix by the network.  It must
            initiate another PDP-Context activation of the other
            address family in addition to the one already activated
            for a given Access Point Name (APN).  The purpose of
            initiating a second PDP-Context is to achieve dual-stack
            connectivity by means of two PDP-Contexts.
         *  If the subscription data or network configuration allows
            only one IP address family (IPv4 or IPv6), the cellular
            host must not request a second PDP-Context to the same
            APN for the other IP address family.
         The network informs the cellular host about allowed Packet
         Data Protocol (PDP) types by means of Session Management
         (SM) cause codes.  In particular, the following cause codes
         can be returned:
         *  cause #50 "PDP type IPv4 only allowed" - This cause code
            is used by the network to indicate that only PDP type
            IPv4 is allowed for the requested Public Data Network
            (PDN) connectivity.
         *  cause #51 "PDP type IPv6 only allowed" - This cause code
            is used by the network to indicate that only PDP type
            IPv6 is allowed for the requested PDN connectivity.
         *  cause #52 "single address bearers only allowed" - This
            cause code is used by the network to indicate that the
            requested PDN connectivity is accepted with the
            restriction that only single IP version bearers are
            allowed.
         The text above focuses on the specification (an excerpt
         from [TS.23060], [TS.23401], and [TS.24008]) that explains
         the behavior for requesting IPv6-related PDP-Context(s).

C_REC#3: The cellular host must support the Protocol Configuration

         Options (PCOs) [TS.24008] to retrieve the IPv6 address(es)
         of the Recursive DNS server(s).
            The 3GPP network communicates parameters by means of the
            protocol configuration options information element when
            activating, modifying, or deactivating a PDP-Context.
            PCO is a convenient method to inform the cellular host
            about various services, including DNS server
            information.  It does not require additional protocol to
            be supported by the cellular host and it is already
            deployed in IPv4 cellular networks to convey such DNS
            information.

C_REC#4: The cellular host must support IPv6-aware Traffic Flow

         Templates (TFTs) [TS.24008].
            Traffic Flow Templates are employing a packet filter to
            couple an IP traffic with a PDP-Context.  Thus, a
            dedicated PDP-Context and radio resources can be
            provided by the cellular network for certain IP traffic.

C_REC#5: If the cellular host receives the DNS information in

         several channels for the same interface, the following
         preference order must be followed:
            1.  PCO
            2.  RA
            3.  DHCPv6
         The purpose of this recommendation is to guarantee for a
         deterministic behavior to be followed by all cellular hosts
         when the DNS information is received in various channels.

C_REC#6: Because of potential operational deficiencies to be

         experienced in some roaming situations, the cellular host
         must be able to be configured with a home PDP-Context
         type(s) and a roaming PDP-Context type(s).  The purpose of
         the roaming profile is to limit the PDP type(s) requested
         by the cellular host when out of the home network.  Note
         that distinct PDP type(s) and APN(s) can be configured for
         home and roaming cases.
            A detailed analysis of roaming failure cases is included
            in RFC7445.
            The configuration can be either local to the device or
            be managed dynamically using, for example, Open Mobile
            Alliance (OMA) management.  The support of dynamic means
            is encouraged.

C_REC#7: In order to ensure IPv4 service continuity in an IPv6-only

         deployment context, the cellular host should support a
         method to learn PREFIX64(s).
            In the context of NAT64, IPv6-enabled applications
            relying on address referrals will fail because an
            IPv6-only client will not be able to make use of an IPv4
            address received in a referral.  This feature allows for
            solving the referral problem (because an IPv6-enabled
            application can construct IPv4-embedded IPv6 addresses
            RFC6052) and, also, for distinguishing between
            IPv4-converted IPv6 addresses and native IPv6 addresses.
            In other words, this feature contributes to offload both
            the CLAT module and NAT64 devices.  Refer to Section 3
            of RFC7051 for an inventory of the issues related to
            the discovery of PREFIX64(s).
            In environments based on the Port Control Protocol
            (PCP), cellular hosts should follow RFC7225 to learn
            the IPv6 Prefix used by an upstream PCP-controlled NAT64
            device.  If PCP is not enabled, the cellular host should
            implement the method specified in RFC7050 to retrieve
            the PREFIX64.

C_REC#8: In order to ensure IPv4 service continuity in an IPv6-only

         deployment context, the cellular host should implement the
         CLAT RFC6877 function in compliance with RFC6052,
         RFC6145, and RFC6146.
            The CLAT function in the cellular host allows for
            IPv4-only application and IPv4 referrals to work on an
            IPv6-only connectivity.  The more applications are
            address family independent, the less the CLAT function
            is solicited.  The CLAT function requires a NAT64
            capability RFC6146 in the network.
            The cellular host should only invoke CLAT in the absence
            of IPv4 connectivity on the cellular side, i.e., when
            the network does not assign an IPv4 address on the
            cellular interface.  Note, NAT64 assumes an IPv6-only
            mode RFC6146.
            The IPv4 Service Continuity Prefix used by CLAT is
            defined in RFC7335.
            CLAT and/or NAT64 do not interfere with native IPv6
            communications.
            CLAT may not be required in some contexts, e.g., if
            other solutions such as Bump-in-the-Host (BIH) RFC6535
            are supported.
            The cellular device can act as a CE router connecting
            various IP hosts on a LAN segment; this is also the case
            with using WLAN (Wireless LAN) tethering or a WLAN
            hotspot from the cellular device.  Some of these IP
            hosts can be dual-stack, others are IPv6-only or
            IPv4-only.  IPv6-only connectivity on the cellular
            device does not allow IPv4-only sessions to be
            established for hosts connected on the LAN segment of
            the cellular device.  IPv4 session establishment
            initiated from hosts located on the LAN segment side and
            destined for IPv4 nodes must be maintained.  A solution
            is to integrate the CLAT function to the LAN segment in
            the cellular device.

C_REC#9: The cellular host may be able to be configured to limit PDP

         type(s) for a given APN.  The default mode is to allow all
         supported PDP types.  Note, C_REC#2 discusses the default
         behavior for requesting PDP-Context type(s).
            This feature is useful to drive the behavior of the UE
            to be aligned with (1) service-specific constraints such
            as the use of IPv6-only for VoLTE, (2) network
            conditions with regard to the support of specific PDP
            types (e.g., IPv4v6 PDP-Context is not supported), (3)
            IPv4 sunset objectives, (4) subscription data, etc.
            Note, a cellular host changing its connection between an
            IPv6-specific APN and an IPv4-specific APN will
            interrupt related network connections.  This may be
            considered as a brokenness situation by some
            applications.
            The configuration can be either local to the device or
            be managed dynamically using, for example, OMA
            management.  The support of dynamic means is encouraged.

Recommendations for Cellular Devices with LAN Capabilities

This section focuses on cellular devices (e.g., CE routers, smartphones, or dongles with tethering features) that provide IP connectivity to other devices connected to them. In this case, all connected devices are sharing the same 2G, 3G, or LTE connection. In addition to the generic recommendations listed in Section 2, these cellular devices have to meet the recommendations listed below.

L_REC#1: For deployments that require that the same /64 prefix be

         shared, the cellular device should support RFC7278 to
         enable sharing a /64 prefix between the LAN and the WAN
         interfaces.  The WAN interface is the one towards the
         Gateway GPRS Support Node (GGSN) / Packet Data Network
         Gateway (PGW).
            Prefix Delegation (refer to L_REC#2) is the target
            solution for distributing prefixes in the LAN side but,
            because the device may attach to earlier 3GPP release
            networks, a means to share a /64 prefix is also
            recommended RFC7278.
            RFC7278 must be invoked only if Prefix Delegation is
            not in use.

L_REC#2: The cellular device must support Prefix Delegation

         capabilities RFC3633 and must support the Prefix Exclude
         Option for DHCPv6-based Prefix Delegation as defined in
         RFC6603.  Particularly, it must behave as a Requesting
         Router.
            Cellular networks are more and more perceived as an
            alternative to fixed broadband networks for home IP-
            based services delivery; especially with the advent of
            smartphones and 3GPP data dongles.  There is a need for
            an efficient mechanism to assign larger prefixes (other
            than /64s) to cellular hosts so that each LAN segment
            can get its own /64 prefix and multi-link subnet issues
            to be avoided.
            In case a prefix is delegated to a cellular host using
            DHCPv6, the cellular device will be configured with two
            prefixes:
            (1)  one for the 3GPP link allocated using the Stateless
                 Address Autoconfiguration (SLAAC) mechanism and
            (2)  another one delegated for LANs acquired during the
                 Prefix Delegation operation.
            Note that the 3GPP network architecture requires both
            the WAN and the delegated prefix to be aggregatable so
            the subscriber can be identified using a single prefix.
            Without the Prefix Exclude Option, the delegating router
            (GGSN/PGW) will have to ensure compliance with RFC3633
            (e.g., halving the delegated prefix and assigning the
            WAN prefix out of the first half and the prefix to be
            delegated to the terminal from the second half).
            Because Prefix Delegation capabilities may not be
            available in some attached networks, L_REC#1 is strongly
            recommended to accommodate early deployments.

L_REC#3: The cellular CE router must be compliant with the

         requirements specified in RFC7084.
            There are several deployments, particularly in emerging
            countries, that rely on mobile networks to provide
            broadband services (e.g., customers are provided with
            mobile CE routers).
            Note, this profile does not require IPv4 service
            continuity techniques listed in Section 4.4 of RFC7084
            because those are specific to fixed networks.  IPv4
            service continuity techniques specific to the mobile
            networks are included in this profile.
            This recommendation does not apply to handsets with
            tethering capabilities; it is specific to cellular CE
            routers in order to ensure the same IPv6 functional
            parity for both fixed and cellular CE routers.  Note,
            modern CE routers are designed with advanced functions
            such as link aggregation that consists in optimizing the
            network usage by aggregating the connectivity resources
            offered via various interfaces (e.g., Digital Subscriber
            Line (DSL), LTE, WLAN, etc.) or offloading the traffic
            via a subset of interfaces.  Ensuring IPv6 feature
            parity among these interface types is important for the
            sake of specification efficiency, service design
            simplification, and validation effort optimization.

L_REC#4: If an RA MTU is advertised from the 3GPP network, the

         cellular device should send RAs to the downstream attached
         LAN devices with the same MTU as seen on the mobile
         interface.
            Receiving and relaying RA MTU values facilitates a more
            harmonious functioning of the mobile core network where
            end nodes transmit packets that do not exceed the MTU
            size of the mobile network's tunnels that use the GPRS
            Tunneling Protocol (GTP).
            [TS.23060] indicates providing a link MTU value of 1358
            octets to the 3GPP cellular device will prevent the IP
            layer fragmentation within the transport network between
            the cellular device and the GGSN/PGW.  More details
            about link MTU considerations can be found in Annex C of
            [TS.23060].

Advanced Recommendations

This section identifies a set of advanced recommendations to fulfill requirements of critical services such as VoLTE. These recommendations apply for mobile hosts, including mobile devices.

A_REC#1: The cellular host must support the RObust Header

         Compression (ROHC) RTP Profile (0x0001) and the ROHC UDP
         Profile (0x0002) for IPv6 RFC5795.  Other ROHC profiles
         may be supported.
            Bandwidth in cellular networks must be optimized as much
            as possible.  ROHC provides a solution to reduce
            bandwidth consumption and to reduce the impact of having
            bigger packet headers in IPv6 compared to IPv4.
            The "RTP/UDP/IP" ROHC profile (0x0001) to compress RTP
            packets and the "UDP/IP" ROHC profile (0x0002) to
            compress Real-time Transport Control Protocol (RTCP)
            packets are required for VoLTE by Section 4.1 of
            IR.92.7.0 [IR92].  Note, [IR92] indicates that the host
            must be able to apply the compression to packets that
            are carried over the voice-media-dedicated radio bearer.

A_REC#2: The cellular host should support PCP RFC6887.

            The support of PCP is seen as a driver to save battery
            consumption exacerbated by keep-alive messages.  PCP
            also gives the possibility of enabling incoming
            connections to the cellular device.  Indeed, because
            several stateful devices may be deployed in wireless
            networks (e.g., NAT64 and/or IPv6 Firewalls), PCP can be
            used by the cellular host to control network-based NAT64
            and IPv6 Firewall functions that will reduce per-
            application signaling and save battery consumption.
            According to [Power], the consumption of a cellular
            device with a keep-alive interval equal to 20 seconds
            (which is the default value in RFC3948, for example)
            is 29 mA (2G) / 34 mA (3G).  This consumption is reduced
            to 16 mA (2G) / 24 mA (3G) when the interval is
            increased to 40 seconds, to 9.1 mA (2G) / 16 mA (3G) if
            the interval is equal to 150 seconds, and to 7.3 mA (2G)
            / 14 mA (3G) if the interval is equal to 180 seconds.
            When no keep-alive is issued, the consumption would be
            5.2 mA (2G) / 6.1 mA (3G).  The impact of keepalive
            messages would be more severe if multiple applications
            are issuing those messages (e.g., SIP, IPsec, etc.).
            Deploying PCP allows cellular hosts to manage protocols
            that convey IP addresses and/or port numbers (see
            Section 2.2 of RFC6889) without requiring Application
            Level Gateways (ALGs) to be enabled at the network side
            (e.g., NAT64).  Avoiding soliciting ALGs makes it easier
            to develop a service without any adherence with the
            underlying transport network.

A_REC#3: In order for host-based validation of DNS Security

         Extensions (DNSSEC) to continue to function in an IPv6-only
         connectivity with NAT64 deployment context, the cellular
         host should embed a DNS64 function (RFC6147).
            This is called "DNS64 in stub-resolver mode" in
            RFC6147.
            As discussed in Section 5.5 of RFC6147, a security-
            aware and validating host has to perform the DNS64
            function locally.
            Because synthetic AAAA records cannot be successfully
            validated in a host, learning the PREFIX64 used to
            construct IPv4-converted IPv6 addresses allows the use
            of DNSSEC RFC4033 RFC4034 RFC4035.  Means to
            configure or discover a PREFIX64 are required on the
            cellular device as discussed in C_REC#7.
            RFC7051 discusses why a security-aware and validating
            host has to perform the DNS64 function locally and why
            it has to be able to learn the proper PREFIX64(s).

A_REC#4: When the cellular host is dual-stack connected (i.e.,

         configured with an IPv4 address and IPv6 prefix), it should
         support means to prefer a native IPv6 connection over a
         connection established through translation devices (e.g.,
         NAT44 and NAT64).
            When both IPv4 and IPv6 DNS servers are configured, a
            dual-stack host must first contact its IPv6 DNS server.
            This preference allows it to offload IPv4-only DNS
            servers.
            Cellular hosts should follow the procedure specified in
            RFC6724 for source address selection.

Security Considerations

The security considerations identified in RFC7066 and RFC6459 are to be taken into account.

In the case of cellular CE routers, compliance with L_REC#3 entails compliance with RFC7084, which in turn recommends compliance with Recommended Simple Security Capabilities in Customer Premises Equipment (CPE) for Providing Residential IPv6 Internet Service RFC6092. Therefore, the security considerations in Section 6 of RFC6092 are relevant. In particular, it bears repeating here that the true impact of stateful filtering may be a reduction in security and that the IETF makes no statement, expressed or implied, as to whether using the capabilities described in any of these documents ultimately improves security for any individual users or for the Internet community as a whole.

The cellular host must be able to generate IPv6 addresses that preserve privacy. The activation of the privacy extension (e.g., using RFC7217) makes it more difficult to track a host over time when compared to using a permanent Interface Identifier. Tracking a host is still possible based on the first 64 bits of the IPv6 address. Means to prevent against such tracking issues may be enabled in the network side. Note, privacy extensions are required by regulatory bodies in some countries.

Host-based validation of DNSSEC is discussed in A_REC#3 (see Section 4).

References

Normative References

[IR92] GSMA, "IMS Profile for Voice and SMS", Official Document

          IR.92 - IMS Profile for Voice and SMS, V7.0, March 2013,
          <http://www.gsma.com/newsroom/wp-content/uploads/2013/04/
          IR.92-v7.0.pdf>.

RFC2460 Deering, S. and R. Hinden, "Internet Protocol, Version 6

          (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460,
          December 1998, <http://www.rfc-editor.org/info/rfc2460>.

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,
          <http://www.rfc-editor.org/info/rfc3596>.

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,
          <http://www.rfc-editor.org/info/rfc3633>.

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,
          <http://www.rfc-editor.org/info/rfc3986>.

RFC5795 Sandlund, K., Pelletier, G., and L-E. Jonsson, "The RObust

          Header Compression (ROHC) Framework", RFC 5795,
          DOI 10.17487/RFC5795, March 2010,
          <http://www.rfc-editor.org/info/rfc5795>.

RFC5954 Gurbani, V., Ed., Carpenter, B., Ed., and B. Tate, Ed.,

          "Essential Correction for IPv6 ABNF and URI Comparison in
          RFC 3261", RFC 5954, DOI 10.17487/RFC5954, August 2010,
          <http://www.rfc-editor.org/info/rfc5954>.

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,
          <http://www.rfc-editor.org/info/rfc6052>.

RFC6603 Korhonen, J., Ed., Savolainen, T., Krishnan, S., and O.

          Troan, "Prefix Exclude Option for DHCPv6-based Prefix
          Delegation", RFC 6603, DOI 10.17487/RFC6603, May 2012,
          <http://www.rfc-editor.org/info/rfc6603>.

RFC7066 Korhonen, J., Ed., Arkko, J., Ed., Savolainen, T., and S.

          Krishnan, "IPv6 for Third Generation Partnership Project
          (3GPP) Cellular Hosts", RFC 7066, DOI 10.17487/RFC7066,
          November 2013, <http://www.rfc-editor.org/info/rfc7066>.

[TS.23060]

          3GPP, "General Packet Radio Service (GPRS); Service
          description; Stage 2", 3GPP TS 23.060 13.6.0, March 2016,
          <http://www.3gpp.org/DynaReport/23060.htm>.

[TS.23401]

          3GPP, "General Packet Radio Service (GPRS) enhancements
          for Evolved Universal Terrestrial Radio Access Network
          (E-UTRAN) access", 3GPP TS 23.401 13.6.1, March 2016,
          <http://www.3gpp.org/DynaReport/23401.htm>.

[TS.24008]

          3GPP, "Mobile radio interface Layer 3 specification; Core
          network protocols; Stage 3", 3GPP TS 24.008 13.5.0, March
          2016, <http://www.3gpp.org/DynaReport/24008.htm>.

Informative References

[OECD] Organisation for Economic Co-operation and Development

          (OECD), "The Economics of the Transition to Internet
          Protocol version 6 (IPv6)", DOI 10.1787/5jxt46d07bhc-en,
          November 2014, <http://www.oecd.org/officialdocuments/publ
          icdisplaydocumentpdf/?cote=DSTI/ICCP/CISP%282014%293/
          FINAL&docLanguage=En>.

[Power] Haverinen, H., Siren, J., and P. Eronen, "Energy

          Consumption of Always-On Applications in WCDMA Networks",
          Proceedings of IEEE 65: Vehicular Technology
          Conference, VTC2007-Spring, pp 964-968,
          DOI 10.1109/VETECS.2007.207, April 2007,
          <http://ieeexplore.ieee.org/xpl/
          articleDetails.jsp?arnumber=4212635>.

[R3GPP] 3GPP, "The Mobile Broadband Standard: Releases", 2016,

          <http://www.3gpp.org/specifications/67-releases>.

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,
          <http://www.rfc-editor.org/info/rfc3261>.

RFC3948 Huttunen, A., Swander, B., Volpe, V., DiBurro, L., and M.

          Stenberg, "UDP Encapsulation of IPsec ESP Packets",
          RFC 3948, DOI 10.17487/RFC3948, January 2005,
          <http://www.rfc-editor.org/info/rfc3948>.

RFC4033 Arends, R., Austein, R., Larson, M., Massey, D., and S.

          Rose, "DNS Security Introduction and Requirements",
          RFC 4033, DOI 10.17487/RFC4033, March 2005,
          <http://www.rfc-editor.org/info/rfc4033>.

RFC4034 Arends, R., Austein, R., Larson, M., Massey, D., and S.

          Rose, "Resource Records for the DNS Security Extensions",
          RFC 4034, DOI 10.17487/RFC4034, March 2005,
          <http://www.rfc-editor.org/info/rfc4034>.

RFC4035 Arends, R., Austein, R., Larson, M., Massey, D., and S.

          Rose, "Protocol Modifications for the DNS Security
          Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
          <http://www.rfc-editor.org/info/rfc4035>.

RFC6092 Woodyatt, J., Ed., "Recommended Simple Security

          Capabilities in Customer Premises Equipment (CPE) for
          Providing Residential IPv6 Internet Service", RFC 6092,
          DOI 10.17487/RFC6092, January 2011,
          <http://www.rfc-editor.org/info/rfc6092>.

RFC6145 Li, X., Bao, C., and F. Baker, "IP/ICMP Translation

          Algorithm", RFC 6145, DOI 10.17487/RFC6145, April 2011,
          <http://www.rfc-editor.org/info/rfc6145>.

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, <http://www.rfc-editor.org/info/rfc6146>.

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,
          <http://www.rfc-editor.org/info/rfc6147>.

RFC6342 Koodli, R., "Mobile Networks Considerations for IPv6

          Deployment", RFC 6342, DOI 10.17487/RFC6342, August 2011,
          <http://www.rfc-editor.org/info/rfc6342>.

RFC6434 Jankiewicz, E., Loughney, J., and T. Narten, "IPv6 Node

          Requirements", RFC 6434, DOI 10.17487/RFC6434, December
          2011, <http://www.rfc-editor.org/info/rfc6434>.

RFC6459 Korhonen, J., Ed., 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,
          <http://www.rfc-editor.org/info/rfc6459>.

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,
          <http://www.rfc-editor.org/info/rfc6535>.

RFC6724 Thaler, D., Ed., Draves, R., Matsumoto, A., and T. Chown,

          "Default Address Selection for Internet Protocol Version 6
          (IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012,
          <http://www.rfc-editor.org/info/rfc6724>.

RFC6877 Mawatari, M., Kawashima, M., and C. Byrne, "464XLAT:

          Combination of Stateful and Stateless Translation",
          RFC 6877, DOI 10.17487/RFC6877, April 2013,
          <http://www.rfc-editor.org/info/rfc6877>.

RFC6887 Wing, D., Ed., Cheshire, S., Boucadair, M., Penno, R., and

          P. Selkirk, "Port Control Protocol (PCP)", RFC 6887,
          DOI 10.17487/RFC6887, April 2013,
          <http://www.rfc-editor.org/info/rfc6887>.

RFC6889 Penno, R., Saxena, T., Boucadair, M., and S. Sivakumar,

          "Analysis of Stateful 64 Translation", RFC 6889,
          DOI 10.17487/RFC6889, April 2013,
          <http://www.rfc-editor.org/info/rfc6889>.

RFC7050 Savolainen, T., Korhonen, J., and D. Wing, "Discovery of

          the IPv6 Prefix Used for IPv6 Address Synthesis",
          RFC 7050, DOI 10.17487/RFC7050, November 2013,
          <http://www.rfc-editor.org/info/rfc7050>.

RFC7051 Korhonen, J., Ed. and T. Savolainen, Ed., "Analysis of

          Solution Proposals for Hosts to Learn NAT64 Prefix",
          RFC 7051, DOI 10.17487/RFC7051, November 2013,
          <http://www.rfc-editor.org/info/rfc7051>.

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,
          <http://www.rfc-editor.org/info/rfc7084>.

RFC7217 Gont, F., "A Method for Generating Semantically Opaque

          Interface Identifiers with IPv6 Stateless Address
          Autoconfiguration (SLAAC)", RFC 7217,
          DOI 10.17487/RFC7217, April 2014,
          <http://www.rfc-editor.org/info/rfc7217>.

RFC7225 Boucadair, M., "Discovering NAT64 IPv6 Prefixes Using the

          Port Control Protocol (PCP)", RFC 7225,
          DOI 10.17487/RFC7225, May 2014,
          <http://www.rfc-editor.org/info/rfc7225>.

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,
          DOI 10.17487/RFC7278, June 2014,
          <http://www.rfc-editor.org/info/rfc7278>.

RFC7335 Byrne, C., "IPv4 Service Continuity Prefix", RFC 7335,

          DOI 10.17487/RFC7335, August 2014,
          <http://www.rfc-editor.org/info/rfc7335>.

RFC7445 Chen, G., Deng, H., Michaud, D., Korhonen, J., and M.

          Boucadair, "Analysis of Failure Cases in IPv6 Roaming
          Scenarios", RFC 7445, DOI 10.17487/RFC7445, March 2015,
          <http://www.rfc-editor.org/info/rfc7445>.

[TS.23402]

          3GPP, "Architecture enhancements for non-3GPP accesses",
          3GPP TS 23.401 13.5.0, March 2016,
          <http://www.3gpp.org/DynaReport/23402.htm>.

Acknowledgements

Many thanks to C. Byrne, H. Soliman, H. Singh, L. Colliti, T. Lemon, B. Sarikaya, M. Mawatari, M. Abrahamsson, P. Vickers, V. Kuarsingh, E. Kline, S. Josefsson, A. Baryun, J. Woodyatt, T. Kossut, B. Stark, and A. Petrescu for the discussion in the v6ops mailing list and for the comments.

Thanks to A. Farrel, B. Haberman, and K. Moriarty for the comments during the IESG review.

Special thanks to T. Savolainen, J. Korhonen, J. Jaeggli, F. Baker, L.M. Contreras Murillo, and M. Abrahamsson for their detailed reviews and comments.

Authors' Addresses

David Binet Orange Rennes France

Email: [email protected]

Mohamed Boucadair Orange Rennes 35000 France

Email: [email protected]

Ales Vizdal Deutsche Telekom AG Tomickova 2144/1 Prague, 148 00 Czech Republic

Email: [email protected]

Gang Chen China Mobile 29, Jinrong Avenue Xicheng District, Beijing 100033 China

Email: [email protected], [email protected]

Nick Heatley EE The Point, 37 North Wharf Road, London W2 1AG United Kingdom

Email: [email protected]

Ross Chandler eircom | meteor 1HSQ St. John's Road Dublin 8 Ireland

Email: [email protected]

Dave Michaud Rogers Communications 8200 Dixie Rd. Brampton, ON L6T 0C1 Canada

Email: [email protected]

Diego R. Lopez Telefonica I+D Don Ramon de la Cruz, 82 Madrid 28006 Spain

Phone: +34 913 129 041 Email: [email protected]

Walter Haeffner Vodafone D2 GmbH Ferdinand-Braun-Platz 1 Duesseldorf 40549 Germany

Email: [email protected]