Internet Engineering Task Force C. Zhou Internet-Draft T. Taylor Intended status: Standards Track Huawei Technologies Expires: April 21, 2014 Q. Sun China Telecom M. Boucadair France Telecom October 18, 2013 Attribute-Value Pairs For Provisioning Customer Equipment Supporting IPv4-Over-IPv6 Transitional Solutions draft-zhou-dime-4over6-provisioning-02 Abstract During the transition from IPv4 to IPv6, customer equipment may have to support one of the various transition methods that have been or are currently being defined for carrying IPv4 packets over IPv6. Work is currently in progress to enumerate the information that needs to be provisioned on a customer edge router to support a list of transition techniques based on tunneling IPv4 in IPv6, with a view to defining reusable components for a reasonable transition path between these techniques. To the extent that the provisioning is done dynamically, AAA support is needed to provide the information to the network server responsible for passing the information to the customer equipment. This document specifies Diameter attribute-value pairs to be used for that purpose. 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 April 21, 2014. Copyright Notice Zhou, et al. Expires April 21, 2014 [Page 1] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 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 . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Description of the Parameters Required By Each Transition Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Parameters For Dual-Stack Lite . . . . . . . . . . . . . 4 2.2. Public IPv4 Over IPv6 . . . . . . . . . . . . . . . . . . 4 2.3. Light Weight IPv4 Over IPv6 (LW4o6) . . . . . . . . . . . 5 2.4. Mapping of Address and Port with Encapsulation (MAP-E) . 5 2.5. Summing Up . . . . . . . . . . . . . . . . . . . . . . . 6 3. Attribute-Value Pair Definitions . . . . . . . . . . . . . . 6 3.1. DS-Lite Attributes . . . . . . . . . . . . . . . . . . . 6 3.1.1. ASM-Prefix64 . . . . . . . . . . . . . . . . . . . . 7 3.1.2. SSM-Prefix64 . . . . . . . . . . . . . . . . . . . . 7 3.1.3. Unicast-Prefix64 . . . . . . . . . . . . . . . . . . 8 3.2. Public Unshared IPv4 Address . . . . . . . . . . . . . . 8 3.3. Light-Weight 4over6 Attributes . . . . . . . . . . . . . 8 3.4. MAP-E Attributes . . . . . . . . . . . . . . . . . . . . 9 3.5. Mapping Rule . . . . . . . . . . . . . . . . . . . . . . 10 3.5.1. EA Field Length . . . . . . . . . . . . . . . . . . . 10 3.5.2. PSID Offset . . . . . . . . . . . . . . . . . . . . . 11 3.6. Border Router IPv6 Address . . . . . . . . . . . . . . . 11 3.7. IPv4 Prefix or Address . . . . . . . . . . . . . . . . . 11 3.8. IPv6 Prefix or Address . . . . . . . . . . . . . . . . . 11 3.9. Port Set Identifier . . . . . . . . . . . . . . . . . . . 11 3.10. Mesh Or Hub And Spoke . . . . . . . . . . . . . . . . . . 12 4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 6. Security Considerations . . . . . . . . . . . . . . . . . . . 12 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 7.1. Normative References . . . . . . . . . . . . . . . . . . 12 7.2. Informative References . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 Zhou, et al. Expires April 21, 2014 [Page 2] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 1. Introduction A number of transition technologies have been or are being defined to allow IPv4 packets to pass between hosts and IPv4 networks over an intervening IPv6 network while minimizing the number of public IPv4 addresses that need to be consumed by the hosts. Different operators will deploy different technologies, and sometimes one operator will use more than one technology, depending on what is supported by the available equipment and upon other factors both technical and economic. Each technique requires the provisioning of some subscriber-specific information on the customer edge device. The provisioning may be by DHCP or by some other method. This document is indifferent to the specific provisioning technique used, but assumes that the information originates in the AAA infrastructure because in some networks, the user configuration information may be managed by AAA (Authentication, Authorization, and Accounting) servers. In a fixed line broadband network, the Broadband Network Gateways (BNGs) act as the access gateway of users. When the BR and BNG are co-located in one device, the approach defined in [I-D.ietf-softwire-map-radius] could be used to acquire the subscriber-specific information via RADIUS. In some deployments when the location of the BR is higher than BNG, the subscriber-specific information will be pushed from AAA server to the BR actively via Diameter [RFC6733]. To allow the information to be carried in Diameter , this document specifies a number of attribute-value pairs (AVPs) for the purpose. This document takes as its scope the set of transition methods provided for by [I-D.ietf-softwire-unified-cpe]. That document enumerates the information that must be provisioned in the customer edge router to support Dual-Stack Lite [RFC6333], Public IPv4 Over IPv6 [I-D.ietf-softwire-public-4over6], Light Weight IPv4 Over IPv6 (LW4o6) [I-D.ietf-softwire-lw4over6], and Mapping of Address and Port with Encapsulation (MAP-E) [I-D.ietf-softwire-map]. Several documents provide related specifications for RADIUS [RFC2865], for individual transition methods. Potentially there could be a reconciliation between the contents of those documents and the present one, but that has not been done in the present version of this document. 1.1. Requirements 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]. Zhou, et al. Expires April 21, 2014 [Page 3] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 2. Description of the Parameters Required By Each Transition Method This section reviews the parameters that need to be provisioned for each of the transition methods listed above. This enumeration provides the justification for the AVPs defined in the next section. Since most of the transition methods dealt with here are works in progress, this section is subject to modification in future versions. A means is required to indicate which transition method(s) a given subscriber is allowed to use. [I-D.ietf-softwire-unified-cpe] specifies how to infer the intended method from other DHCP parameters received. The approach taken in this document is to specify grouped AVPs specific to the individual transition methods. The operator can control which transition method a given subscriber uses by ensuring that AAA passes only the grouped AVP relevant to that method. 2.1. Parameters For Dual-Stack Lite Dual-Stack Lite is documented in [RFC6333]. It requires the following parameters to be provisioned at the B4 at the customer premises. This enumeration does not include the normal provisioning of an IPv6 prefix to the customer equipment. The section numbers shown are where these requirements are indicated in [RFC6333]. o IPv6 address of the border router (AFTR) (sec. 5.4); o IPv6 address of a DNS recursive server (sec. 5.5). This is probably supplied already independently of transition technology, so does not have to be covered here. o optionally, the IPv4 address of the B4 interface facing the tunnel, where the default value in the absence of provisioning is 192.0.0.2 and valid values are 192.0.0.2 through 192.0.0.7 (sec. 5.7). Provisioning this information through AAA is problematic because it is most likely used in a case where multiple B4 instances occupy the same device. This document therefore assumes that the B4 interface address is determined by other means (implementation- dependent or static assignment). 2.2. Public IPv4 Over IPv6 Public IPv4 Over IPv6 is described in [I-D.ietf-softwire-public-4over6]. Besides the usual IPv6 prefix or address information, it requires two parameters to be provisioned to the customer equipment: o a public IPv4 address; Zhou, et al. Expires April 21, 2014 [Page 4] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 o IPv6 address of the border router It also requires per-subscriber provisioning on the border router: o binding between the customer IPv4 address and the customer IPv6 prefix, for routing of incoming packets to the correct tunnel. 2.3. Light Weight IPv4 Over IPv6 (LW4o6) Light Weight IPv4 Over IPv6 (LW4o6) is documented in [I-D.ietf-softwire-lw4over6]. Its provisioning requirements are exactly the same as those for Public 4over6 with one addition: o both the customer equipment and the border router are provided with a port set identifier identifying the set of ports to which the subscriber's incoming and outgoing packets on the public side are restricted. The port selection algorithm and port set identifier as such are not discussed in the draft. For the present version of this document, it is assumed that the algorithm is known in advance and the port set identifier has the form of an index ranging from zero to the number of subscribers sharing a given address less 1. This is similar to the port set identifier in MAP-E, described next. 2.4. Mapping of Address and Port with Encapsulation (MAP-E) Mapping of Address and Port with Encapsulation (MAP-E) is described in [I-D.ietf-softwire-map]. MAP-E requires the provisioning of the following per-subscriber information at the customer edge device: o whether the device is to operate in mesh or hub-and-spoke mode; o the IPv6 address of one or more border routers; o the specially constructed End-user IPv6 prefix for the customer edge device. [I-D.ietf-softwire-map] suggests that this would be supplied as part of normal IPv6 provisioning, so it can be ignored as a requirement here. o the Basic Mapping Rule for the customer edge device. This includes the following parameters: * the rule IPv6 prefix and length; * the rule IPv4 prefix and length; * the number of "Extended Address" (EA) bits included in the End- user IPv6 prefix; Zhou, et al. Expires April 21, 2014 [Page 5] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 * of those Extended Address bits, the number that precede the port set identifier. The default value is 6. o in mesh mode only, zero or more Forwarding Mapping Rules, containing the same parameters as the Basic Mapping rule. o optionally, the port set identifier if the EA bits do not carry it. The border router needs to be configured with the superset of the Forwarding MAP Rules passed to the customer sites it serves. Since this is not subscriber-specific, even though it introduces no new requirements to this document, it is out of scope. 2.5. Summing Up It appears that the following items are common to two or more methods and the corresponding AVPs to carry them can be reused: o the IPv6 address of the border router; o an IPv4 prefix and length (could be a /32); o a port set identifier. The remaining requirements are method-specific: o for Public 4over6 and LW4o6, a binding between a customer IPv6 prefix or address and an IPv4 address; o for MAP-E, the indication of whether mesh mode or hub-and-spoke mode is to be used; o for MAP-E, a Grouped AVP expressing a MAP Rule. 3. Attribute-Value Pair Definitions This section provides the specifications for the AVPs needed to meet the requirements summarized in Section 2.5. Within the context of their usage, all of these AVPs MUST have the M bit set and the V bit cleared. 3.1. DS-Lite Attributes The DS-Lite-Attributes AVP is of type Grouped. It contains the IPv6 address of the AFTR and optionally the multicast-related prefixes needed for providing native IPv4 multicast over IPv6 using DS-Lite, as specified in [I-D.softwire-dslite-multicast]. Zhou, et al. Expires April 21, 2014 [Page 6] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 DS-Lite-Attributes ::= < AVP Header: TBD01 > { Border-Router-IPv6-Address } 0*1[ ASM-Prefix64 ] 0*1[ SSM-Prefix64 ] 0*1[ Unicast-Prefix64 ] *[ AVP ] Figure 1 The Border-Router-IPv6-Address AVP is defined in Section 3.6. Within the DS-Lite-Attributes AVP, it provides the IPv6 address of the AFTR. This AVP MUST be present. The remaining AVPs are defined in this section, and MAY be included if the subscriber is to receive native IPv4 multicast service over IPv6 using DS-Lite. If either ASM-Prefix64 or SSM-Prefix64 or both are present, Unicast-Prefix64 MUST also be present. 3.1.1. ASM-Prefix64 The ASM-Prefix64 AVP (AVP Code TBD02) is derived from base type OctetString. It is a discriminated union representing the combination of the prefix length (number of bits) in the first octet, followed by the prefix itself, most significant octet first, padded with zeroes at the low-order end to an octet boundary. Valid values of the prefix length are from 0 to 96, where 0 indicates that the prefix is absent. This AVP conveys the IPv6 multicast prefix to be used to synthesize the IPv4-embedded IPv6 addresses of the multicast groups in the Any- Source Multicast (ASM) mode. The conveyed multicast IPv6 prefix MUST belong to the ASM range. 3.1.2. SSM-Prefix64 The SSM-Prefix64 AVP (AVP Code TBD03) is derived from base type OctetString. It is a discriminated union representing the combination of the prefix length (number of bits) in the first octet, followed by the prefix itself, most significant octet first, padded with zeroes at the low-order end to an octet boundary. Valid values of the prefix length are 0 and 96, where 0 indicates that the prefix is absent. This AVP conveys the IPv6 multicast prefix to be used to synthesize the IPv4-embedded IPv6 addresses of the multicast groups in the Source-Specific Multicast [RFC4607] mode. The conveyed multicast IPv6 prefix MUST belong to the SSM range. This prefix is likely to be a /96. Zhou, et al. Expires April 21, 2014 [Page 7] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 3.1.3. Unicast-Prefix64 The Unicast-Prefix64 AVP (AVP Code TBD04) is derived from base type OctetString. It is a discriminated union representing the combination of the prefix length (number of bits) in the first octet, followed by the prefix itself, most significant octet first, padded with zeroes at the low-order end to an octet boundary. Valid values of the prefix length are 0, 32, 48, 56, 64 and 96, where 0 indicates that the prefix is absent. This AVP conveys the IPv6 unicast prefix to be used in SSM mode for constructing the IPv4-embedded IPv6 addresses representing the IPv4 multicast sources in the IPv6 domain. Unicast-Prefix64 may also be used to extract the IPv4 address from the received multicast data flows. The address mapping must follow the guidelines documented in [RFC6052]. 3.2. Public Unshared IPv4 Address The Public-Unshared-IPv4-Address AVP (AVP Code TBD05) is of type Address as defined in Section 4.3 of [RFC6733]. It provides an unshared IPv4 address assigned to the customer edge device. It applies to Public 4over6 (always) and to LW4o6 and MAP-E in the case of 1-1 mapping. The recipient of this AVP can determine which of the transition methods is applicable from the presence or absence of LW4o6-specific or MAP-E-specific additional attributes. Since the content is an IPv4 address, the AVP Length MUST be set to 14 and the first two octets MUST contain 0x0001 (IPv4). 3.3. Light-Weight 4over6 Attributes The Light-Weight-4over6-Attributes AVP (AVP Code TBD06) is of type Grouped. It contains the IPv6 address of the Border Router, optionally the IPv6 prefix assigned to the customer edge device, and optionally the port set identifier assigned to the customer edge device. Light-Weight-4over6-Attributes ::= < AVP Header: TBD06 > { Border-Router-IPv6-Address } 0*1[ IPv6-Prefix-Or-Addr ] 0*1[ Port-Set-Identifier ] *[ AVP ] Figure 2 Zhou, et al. Expires April 21, 2014 [Page 8] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 The Border-Router-IPv6-Address AVP is defined in Section 3.6 and provides the IPv6 address of the Border Router. This AVP MUST be present. The IPv6-Prefix-Or-Addr AVP is defined in Section 3.8. Within the Light-Weight-4over6-Attributes AVP, it provides the IPv6 prefix assigned to the customer edge device. If this AVP is absent, it is assumed that the same information is conveyed to the recipient of the Light-Weight-4over6-Attributes AVP by another AVP in the subscriber profile. The Port-Set-Identifier AVP is defined in Section 3.9. It identifies the specific set of ports assigned to the customer edge device. This AVP MUST be present except when 1-1 mapping mode is being provisioned, when it MUST NOT be present. In this version of this document it is assumed that the algorithm and parameters used to derive individual port values from the port set identifier are already known to the recipient. 3.4. MAP-E Attributes The MAP-E-Attributes AVP (AVP Code TBD07) is of type Grouped. It contains the addresses of one or more Border Routers in the same MAP-E domain as the customer edge device, an indicator of whether mesh mode or hub-and-spoke mode is used in the domain, optionally the end-user IPv6 prefix assigned to the customer edge device, and one or more mapping rules. MAP-E-Attributes ::= < AVP Header: TBD07 > 1*{ Border-Router-IPv6-Address } { Mesh-Or-Hub-And-Spoke } 0*1[ IPv6-Prefix-Or-Addr ] 1*{ Mapping-Rule } *[ AVP ] Figure 3 The Border-Router-IPv6-Address AVP is defined in Section 3.6 and provides the IPv6 address of the Border Router. At least one instance of this AVP MUST be present. The Mesh-Or-Hub-And-Spoke AVP is defined in Section 3.10. It indicates whether the the MAP-E domain supports mesh mode or hub-and- spoke mode. This AVP MUST be present. The IPv6-Prefix-Or-Addr AVP is defined in Section 3.8. Within the MAP-E-Attributes AVP, it provides the IPv6 prefix assigned to the customer edge device. If this AVP is absent, it is assumed that the Zhou, et al. Expires April 21, 2014 [Page 9] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 same information is conveyed to the recipient of the MAP-E-Attributes AVP by another AVP in the subscriber profile. The Mapping-Rule AVP is defined in Section 3.5. At least one instance of this AVP MUST be present. If the MAP-E domain supports mesh mode, additional Mapping-Rule instances MAY be present. If the MAP-E domain is operating in hub-and-spoke mode, additional Mapping- Rule instances MUST NOT be present. 3.5. Mapping Rule The Mapping-Rule AVP (AVP Code TBD08) is of type Grouped, and is used only in conjunction with MAP-based transition methods (MAP-E and potentially 4rd and MAP-T). Mapping rules are required both by the Border Router and by the customer edge device. The components of the Mapping-Rule AVP are the rule IPv4 prefix or address, the rule IPv6 prefix, the length in bits of the Extended Address field in the End- User IPv6 Prefix assigned to the customer edge device, and optionally the offset in a port number beyond which the port set identifier begins. The syntax of the Mapping-Rule AVP is as follows: Mapping-Rule ::= < AVP Header: TBD08 > { IPv4-Prefix-Or-Addr } { IPv6-Prefix-Or-Addr } { EA-Field-Length } [ PSID-Offset ] *[ AVP ] Figure 4 The IPv4-Prefix-Or-Addr AVP and IPv6-Prefix-Or-Addr AVPs are defined in sections Section 3.7 and Section 3.8 respectively. They MUST be present within the Mapping-Rule AVP. The EA-Field-Length AVP and PSID-Offset AVP are defined in this section. 3.5.1. EA Field Length The EA-Field-Length AVP (AVP Code TBD09) is of type Unsigned32. The valid range for EA-Field-Length extends from 0 to a maximum value defined by [I-D.ietf-softwire-map]. If EA-Field-Length is 0, the subscriber profile MUST also provide an instance of the Public- Unshared-IPv4-Address AVP (AVP Code TBD05). The EA-Field-Length AVP MUST be present within the Mapping-Rule AVP. AVP Length for the EA- Field-Length AVP MUST be set to 12. Zhou, et al. Expires April 21, 2014 [Page 10] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 3.5.2. PSID Offset The PSID-Offset AVP (AVP Code TBD10) is of type Unsigned32. The valid range for PSID-Offset extends from 0 to 15, with a default value given by [I-D.ietf-softwire-map] if the parameter is absent. AVP Length for the PSID-Offset AVP MUST be set to 12. 3.6. Border Router IPv6 Address The Border-Router-IPv6-Address (AVP Code TBD11) is of type Address as defined in Section 4.3 of [RFC6733] and contains the IPv6 address of a border router supporting an IPv6 transition method which will be used by the customer edge device on which this address is provisioned. The address MAY be an anycast address. Since the content is an IPv6 address, the AVP Length MUST be set to 26 and the first two octets MUST contain 0x0002 (IPv6). 3.7. IPv4 Prefix or Address The IPv4-Prefix-Or-Addr (AVP Code TBD12) is derived from base type OctetString. It is a discriminated union representing the combination of the prefix length (number of bits) in the first octet, followed by the prefix itself, most significant octet first, padded with zeroes at the low-order end to an octet boundary. Valid values of the prefix length are from 0 to 32, where 0 indicates that the prefix is absent and 32 indicates a complete address. Correspondingly, the AVP Length can range from 9 to 14. 3.8. IPv6 Prefix or Address The IPv6-Prefix-Or-Addr (AVP Code TBD13) is derived from base type OctetString. It is a discriminated union representing the combination of the prefix length (number of bits) in the first two octets, followed by the prefix itself, most significant octet first, padded with zeroes at the low-order end to an octet boundary. Valid values of the prefix length are from 0 to 128, where 0 indicates that the prefix is absent and 128 indicates a complete address. Correspondingly, the AVP Length can range from 10 to 26. 3.9. Port Set Identifier The Port-Set-Identifier AVP (AVP Code TBD14) is of type Unsigned32 and indicates a set of ports defined by an otherwise-specified algorithm. For a given shared address, each Port-Set-Identifier value MUST identify a separate set of ports. AVP Length for the Port-Set-Identifier AVP MUST be set to 12. Zhou, et al. Expires April 21, 2014 [Page 11] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 3.10. Mesh Or Hub And Spoke The Mesh-Or-Hub-And-Spoke AVP (AVP Code TBD15) is of type Enumerated. It indicates whether the MAP-E domain operates in mesh or hub-and- spoke mode. The possible values are: (1) mesh mode; (2) hub-and-spoke mode. 4. Acknowledgements TBD 5. IANA Considerations This memo requests to IANA to register the following Diameter AVP codes: +-------+--------------------------------+---------------+ | Code | Attribute Name | Reference | +-------+--------------------------------+---------------+ | TBD01 | DS-Lite-Attributes | This document | | TBD02 | ASM-Prefix64 | This document | | TBD03 | SSM-Prefix64 | This document | | TBD04 | Unicast-Prefix64 | This document | | TBD05 | Public-Unshared-IPv4-Address | This document | | TBD06 | Light-Weight-4over6-Attributes | This document | | TBD07 | MAP-E-Attributes | This document | | TBD08 | Mapping-Rule | This document | | TBD09 | EA-Field-Length | This document | | TBD10 | PSID-Offset | This document | | TBD11 | Border-Router-IPv6-Address | This document | | TBD12 | IPv4-Prefix-Or-Addr | This document | | TBD13 | IPv6-Prefix-Or-Addr | This document | | TBD14 | Port-Set-Identifier | This document | +-------+--------------------------------+---------------+ Table 1 6. Security Considerations To come. 7. References 7.1. Normative References Zhou, et al. Expires April 21, 2014 [Page 12] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 [I-D.ietf-softwire-lw4over6] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I. Farrer, "Lightweight 4over6: An Extension to the DS-Lite Architecture (work in progress)", July 2013. [I-D.ietf-softwire-map-radius] Jiang, Sheng., Fu, Yu., Liu, Bing., and Peter. Deacon, "RADIUS Attribute for MAP (work in progress)", June 2013. [I-D.ietf-softwire-map] Troan, O., Dec, W., Li, X., Bao, C., Matsushima, S., Murakami, T., and T. Taylor, "Mapping of Address and Port with Encapsulation (MAP) (work in progress)", August 2013. [I-D.ietf-softwire-public-4over6] Cui, Y., Wu, J., Wu, P., Vautrin, O., and Y. Lee, "Public IPv4 over IPv6 Access Network (work in progress)", July 2013. [I-D.ietf-softwire-unified-cpe] Boucadair, M. and I. Farrer, "Unified IPv4-in-IPv6 Softwire CPE (work in progress)", May 2013. [I-D.softwire-dslite-multicast] Qin, J., Boucadair, M., Jacquenet, C., Lee, Y., and Q. Wang, "Delivery of IPv4 Multicast Services to IPv4 Clients over an IPv6 Multicast Network (work in progress)", October 2013. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- Stack Lite Broadband Deployments Following IPv4 Exhaustion", RFC 6333, August 2011. [RFC6733] Fajardo, V., Arkko, J., Loughney, J., and G. Zorn, "Diameter Base Protocol", RFC 6733, October 2012. 7.2. Informative References [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000. Zhou, et al. Expires April 21, 2014 [Page 13] Internet-Draft AVPs For 4over6 CPE Provisioning October 2013 [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC4607] Holbrook, H. and B. Cain, "Source-Specific Multicast for IP", RFC 4607, August 2006. [RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X. Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, October 2010. Authors' Addresses Cathy Zhou Huawei Technologies Bantian, Longgang District Shenzhen 518129 P.R. China Email: cathy.zhou@huawei.com T. Taylor Huawei Technologies Ottawa Canada Email: tom.taylor.stds@gmail.com Qiong Sun China Telecom P.R.China Phone: 86 10 58552936 Email: sunqiong@ctbri.com.cn M. Boucadair France Telecom Rennes 35000 France Email: mohamed.boucadair@orange.com Zhou, et al. Expires April 21, 2014 [Page 14]