Netext WG X. Zhou Internet-Draft ZTE Corporation Intended status: Standards Track J. Korhonen Expires: April 22, 2013 Nokia Siemens Networks C. Williams Consultant S. Gundavelli Cisco CJ. Bernardos UC3M October 19, 2012 Prefix Delegation for Proxy Mobile IPv6 draft-ietf-netext-pd-pmip-04 Abstract Proxy Mobile IPv6 enables IP mobility for a host without requiring its participation in any mobility signaling, being the network responsible for managing IP mobility on behalf of the host. However, Proxy Mobile IPv6 does not support assigning a prefix to a router and managing its IP mobility. This document specifies an extension to Proxy Mobile IPv6 protocol for supporting network mobility using DHCPv6-based Prefix Delegation. 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 22, 2013. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. Zhou, et al. Expires April 22, 2013 [Page 1] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 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 2. Convention and Terminology . . . . . . . . . . . . . . . . . . 4 3. DHCPv6 Prefix Delegation for Proxy Mobile IPv6 . . . . . . . . 5 3.1. Assumptions . . . . . . . . . . . . . . . . . . . . . . . 5 3.2. Network Mobility Service . . . . . . . . . . . . . . . . . 5 3.3. Binding association with the delegated prefix . . . . . . 6 3.3.1. Mobile Router initiated prefix delegation in PMIPv6 . 6 3.3.2. Refreshing the Delegated Prefix in Proxy Mobile IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.3.3. Deletion of the Delegated Prefix in Proxy Mobile IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.4. Mobile Access Gateway Operation . . . . . . . . . . . . . 8 3.4.1. Extension to Binding Update List Entry Data Structure . . . . . . . . . . . . . . . . . . . . . . 8 3.4.2. Forwarding . . . . . . . . . . . . . . . . . . . . . . 8 3.4.3. Handover . . . . . . . . . . . . . . . . . . . . . . . 9 3.5. Local Mobility Anchor Operation . . . . . . . . . . . . . 9 3.5.1. Extension to Binding Cache Entry Data Structure . . . 9 3.5.2. Forwarding . . . . . . . . . . . . . . . . . . . . . . 9 4. Message formats . . . . . . . . . . . . . . . . . . . . . . . 11 4.1. Home Mobile Network Prefix Option . . . . . . . . . . . . 11 5. Security Considerations . . . . . . . . . . . . . . . . . . . 13 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 8.1. Normative References . . . . . . . . . . . . . . . . . . . 17 8.2. Informative References . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18 Zhou, et al. Expires April 22, 2013 [Page 2] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 1. Introduction Proxy Mobile IPv6 [RFC5213] enables an IPv6 host to move within a PMIPv6-Domain without requiring its participation in any IP mobility signaling. However, PMIPv6 does not support providing a network- based mobility service to a complete network which is roaming within a PMIPv6-Domain without requiring the mobile router of that network to run the Network Mobility Basic Support protocol [RFC3963]. In order to support network mobility in Proxy Mobile IPv6, the IPv6 prefix used by the mobile network should be topologically anchored by the local mobility anchor. DHCPv6 Prefix Delegation [RFC3633] (DHCPv6-PD) can be used to assign mobile network prefix(es) to a mobile router (MR) as specified in DHCPv6 Prefix Delegation for Network Mobility (NEMO) [RFC6276]. However, Proxy Mobile IPv6, as specified in [RFC5213], does not provide mobility support to a network behind a mobile router attached to a PMIPv6-Domain, as the PMIPv6 network entities (i.e., mobile access gateway and local mobility anchor) are not aware of the prefix(es) used by the nodes behind the mobile router. This document describes how DHCPv6 prefix delegation can be used by a mobile router attached to a PMIPv6-Domain to obtain prefix(es) managed by the local mobility anchor, and the extensions required to PMIPv6 to support the mobility of the prefix(es). Zhou, et al. Expires April 22, 2013 [Page 3] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 2. Convention and Terminology 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 [RFC2119]. All the mobility related terms used in this document are to be interpreted as defined in Mobile IPv6 (MIPv6) [RFC6275], Proxy Mobile IPv6 specification [RFC5213], DHCPv6-PD for NEMO [RFC6276], DHCPv6-PD [RFC3633] and Mobility Related Terminology [RFC3753]. This document also provides a context-specific explanation to the following terms used in this document. Mobile Router (MR) Throughout this document, the term mobile router is used to refer to an IP router whose mobility is managed by the network while being attached to a PMIPv6-Domain. The mobile router is not required to participate in any IP mobility related signaling for achieving mobility for an IPv6 prefix that is obtained in that Proxy Mobile IPv6 domain. Home Mobile Network Prefix (HMNP) The HMNP is a prefix delegated to a mobile router and advertised in the mobile network. More than one Home Mobile Network Prefix could be delegated to a mobile router. The HMNP is topologically anchored by the local mobility anchor. While used by the mobile router, the mobile access gateway and local mobility anchor provide mobility service to the mobile router for the HMNP(s). Zhou, et al. Expires April 22, 2013 [Page 4] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 3. DHCPv6 Prefix Delegation for Proxy Mobile IPv6 3.1. Assumptions This specification extends Proxy Mobile IPv6 (PMIPv6) to assign a (home) mobile network prefix to a mobile router (MR) for supporting network mobility. The specification assumes that a mobile router is a regular IPv6 router without mobility management support. The mobile router forwards outgoing packets from its mobile network to the mobile access gateway (MAG), and the MAG delivers the incoming packets to the mobile network via the MR. In order to use DHCPv6-PD as home mobile network prefix assignment mechanism in a PMIPv6-Domain, this specification makes the following assumptions. o The mobile router MUST be able to function as a requesting router (RR; acts as a DHCPv6 client). o The delegating router (DR; acts as a DHCPv6 server) function MUST be co-located with the LMA. o A DHCPv6 Relay Agent (DRA) function (as described in [RFC5213]) MUST be used by the mobile access gateway to be able to intercept the related DHCPv6 message sourced from the mobile router. o The mobile router MUST have obtained a Home Network Prefix (HNP) from the PMIPv6-Domain before initiating a DHCPv6-PD procedure. In case of stateful address configuration, the prefix delegation MAY be performed simultaneously while configuring the Mobile Node Home Address (MN-HoA). o The MR (acting as a RR) SHOULD support Prefix Exclude Option for DHCPv6-PD as described in [RFC6603]. 3.2. Network Mobility Service The network mobility service of a mobile router is indicated by the policy profile defined in [RFC5213]. During the mobile router's initial attachment procedure, the mobile access gateway MUST identify the mobile router and SHOULD acquire the policy profile to determine whether the network mobility service is offered to the mobile router. If the network mobility service needs to be offered to the mobile router, the mobile access gateway MUST set the Mobile Router Flag (R) when sending the Proxy Binding Update (PBU) message to the local mobility anchor. Zhou, et al. Expires April 22, 2013 [Page 5] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 3.3. Binding association with the delegated prefix 3.3.1. Mobile Router initiated prefix delegation in PMIPv6 +-----+ +-----+ + ----+ | MR | | MAG | | LMA | |(RR) | |(DRA)| |(DR) | +-----+ +-----+ +-----+ | | | | |o========================o| 1) | | PMIPv6 tunnel | | |o========================o| 2) |-- Solicit ------>| | | | | 3) | |----------PBU------------>| | | | 4) | |<---------PBA (HMNP)------| | | | 5) | |--- Solicit ------------->| - - - <---+ 6) | |<-- Advertise ------------| | | | | | 7) |<- Advertise -----| | | | | | Optional 8) |-- Request ------>| | | | | | | 9) | |--- Request ------------->| | - - - <---+ 10) | |<-- Reply (HMNP) ---------| | | | 11) |<-- Reply (HMNP) -| | | | | Figure 1: Prefix Delegation in PMIPv6 during the initial attachment to the PMIPv6 Domain The steps required to complete the delegation of IPv6 prefix(es) to a mobile router that is provided with network mobility service are the following (see Figure 1): 1. The PMIPv6 tunnel is set up between the MAG and the LMA as described in [RFC5213]. This requires the MAG to send a regular PBU to the LMA to register the location of the mobile router and set-up the bi-directional tunnel. The LMA binds the allocated home network prefix (HNP) to the Proxy-CoA of the mobile router (i.e., the address of the mobile access gateway where the MR is attached to). Zhou, et al. Expires April 22, 2013 [Page 6] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 2. The mobile router, acting as a "Requesting Router" as described in [RFC3633], sends a DHCPv6 SOLICIT message including one or more IA_PD option(s) to the mobile access gateway (which has a "DHCPv6 Relay Agent" function) to acquire the delegated prefix(es). 3. Upon receiving the DHCPv6 SOLICIT message, the mobile access gateway sends a proxy binding update (PBU) message to the local mobility anchor, including one (or more) Home Mobile Network Prefix (HMNP) mobility option. All the considerations from Section 5.3.1 of [RFC5213] MUST be applied on the encapsulated Proxy Binding Update message. If the mobile access gateway does not know the delegated prefix(es), then the home mobile network prefix in the HMNP option(s) MUST be set to the unspecified address "::" and the prefix length to 0. The local mobility anchor either assigns the MR new delegated prefix(es) or returns the existing one(s). 4. On reception of the proxy binding update, the local mobility anchor returns the assigned prefix(es) in the HMNP option(s) conveyed in a proxy binding acknowledgment (PBA) message sent to the mobile access gateway, unless the prefix(es) included in the PBU was the IPv6 unspecified address "::". The assigned prefix(es) MUST be the same one(s) which will be assigned via DHCPv6PD in step 6. The prefix(es) MUST be added to the delegated prefix(es) in the local mobility anchor binding cache which is extended as described in Section 3.5.1. 5. The DHCPv6 Relay Agent function on the mobile access gateway relays the DHCPv6 SOLICIT message to the delegating router (as described in [RFC3633] ). The delegating router inserts one or more IA_PD option(s) including the delegated prefix(es) in the reply message. Note: steps 6 to 9 are not present if DHCPv6 Rapid Commit is used. 6. The delegating router sends the delegated prefix(es) in one or more IA_PD(s) to the mobile access gateway (acting as "DHCPv6 Relay Agent") inside the DHCPv6 ADVERTISE message. 7. The mobile access gateway relays the DHCPv6 ADVERTISE message to the mobile router. 8. The mobile router sends the DHCPv6 REQUEST message with the IA_PD option(s) received from previous message to the mobile access gateway (which is acting as "DHCPv6 Relay Agent"). Zhou, et al. Expires April 22, 2013 [Page 7] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 9. The DRA function on the mobile access gateway relays the DHCPv6 REQUEST message to the DR. 10. The DR function on the local mobility anchor responds to the REQUEST from the mobile access gateway with a DHCPv6 REPLY message. 11. The RR function on the mobile router receives one or more IA_PD prefix(es) in the DHCPv6 REPLY message sent by the mobile access gateway. 3.3.2. Refreshing the Delegated Prefix in Proxy Mobile IPv6 When the mobile router sends DHCPv6 Renew messages to extend the lifetime of the delegated prefix, these messages are also intercepted by the mobile access gateway (acting as "DHCPv6 Relay Agent") and are relayed to the local mobility anchor (which is acting as "Delegating Router"). 3.3.3. Deletion of the Delegated Prefix in Proxy Mobile IPv6 If the lifetime of the delegated prefix (included in the IA_PD Prefix Option carried by the DHCPv6 Reply message) is set to zero, the mobile access gateway MUST send a proxy binding update message to remove the binding for that home mobile network prefix. 3.4. Mobile Access Gateway Operation 3.4.1. Extension to Binding Update List Entry Data Structure In order to support this specification, the conceptual Binding Update List Entry (BULE) data structure needs to be extended with a new prefix information field as [RFC3963] does. This field is used to store the home mobile network prefix assigned to the mobile router, which is included in the proxy binding acknowledgment. 3.4.2. Forwarding Forwarding packets sent to the MR's home mobile network prefix: o On receiving a packet from the bi-directional tunnel established with the local mobility anchor, the mobile access gateway MUST first decapsulate the packet (removing the outer header) and then use the destination address of the (inner) packet to forward it on the interface through which the destination home mobile network prefix is reachable. Forwarding packets sent by the mobile router: Zhou, et al. Expires April 22, 2013 [Page 8] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 o On receiving packets from a mobile router connected to one access link, the mobile access gateway MUST ensure that there is an established binding for the mobile router and the local mobility anchor for the source home mobile network prefix before tunneling the packet to the MR's local mobility anchor. Other considerations from Section 6.10.5 of [RFC5213] also apply here. 3.4.3. Handover When the mobile router moves from the previously attached mobile access gateway to the target MAG, the newly attached mobile access gateway MAY know the home mobile network prefix(es) which were assigned to the mobile router during the previous attachment. It is out of scope of this specification how the new mobile access gateway could obtain the previously assigned home mobile network prefix(es) (e.g., from some network element such as the previous MAG). After moving to the new MAG, a proxy binding update message including the assigned home mobile network prefix(es) (if available) MUST be sent by the MAG to the LMA. The local mobility anchor MUST check the home mobile network prefix(es) included in the PBU message and return the same assigned home mobile network prefix(es) in the proxy binding acknowledgment message. If the previously assigned mobile network prefix(es) are not known by new MAG, the mobile network prefix(es) MUST be set to unspecified address "::" and the prefix length MUST be set to 0 in the proxy binding update message sent by the new mobile access gateway to the local mobility anchor. In this case, the local mobility anchor MUST return the same previously assigned mobile network prefix(es) in proxy binding acknowledgment message. 3.5. Local Mobility Anchor Operation 3.5.1. Extension to Binding Cache Entry Data Structure In order to support this specification, the conceptual Binding Cache Entry (BCE) data structure needs to be extended with a new prefix information field as [RFC3963] does. This field is used to store the delegated home mobile network prefix(es) assigned to the mobile router and included in the proxy binding update (as described in Section 3.2). 3.5.2. Forwarding Intercepting packets sent to the MR's home mobile network prefix: o When the local mobility anchor is serving the mobile router, it MUST be able to receive/intercept packets destined to the network Zhou, et al. Expires April 22, 2013 [Page 9] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 behind the mobile router. In order to receive these packets, the local mobility anchor MUST be the topological anchor of the MR's home mobile network prefix(es). Forwarding packets to the mobile router: o On receiving a packet from a correspondent node with the destination address matching the MR's home mobile network prefix(es), the local mobility anchor MUST forward the packet through the bi-directional tunnel set up with the mobile router. Other considerations from Section 5.6.2 of [RFC5213] also apply here. Zhou, et al. Expires April 22, 2013 [Page 10] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 4. Message formats This section defines extensions to the Proxy Mobile IPv6 [RFC5213] protocol messages. 4.1. Home Mobile Network Prefix Option A new Home Mobile Network Prefix option is defined for use with the Proxy Binding Update and Proxy Binding Acknowledgment messages exchanged between a local mobility anchor and a mobile access gateway. This option is used for exchanging the mobile router's home mobile network prefix information. There can be multiple Home Mobile Network Prefix options present in the message. The Home Mobile Network Prefix option has an alignment requirement of 8n+2. Its format is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length |K| Reserved | Prefix Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | GRE Key Identifier (optional) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Home Mobile Network Prefix + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type To be assigned by IANA. Length 8-bit unsigned integer indicating the length of the option in octets, excluding the type and length fields. Key present (K) If the Key Present bit is set to 1, then it indicates that the GRE Key Identifier field includes a valide GRE Key. Otherwise, the value of the GRE Key Identifier field MUST be ignored by the Zhou, et al. Expires April 22, 2013 [Page 11] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 receiver. Reserved This field is unused for now. The value MUST be initialized to 0 by the sender and MUST be ignored by the receiver. Prefix Length 8-bit unsigned integer indicating the prefix length of the prefix contained in the option. Generic Routing Encapsulation (GRE) Key Identifier A four-byte optional field containing the GRE key tag as specified in [RFC2890]. If the Key Present flag is set to 0, this field MUST be initialized to 0 by the sender and MUST be ignored by the receiver. This option MAY be used by the LMA to provide differentiated a service to different clients attached to the same mobile router. Home Mobile Network Prefix A sixteen-byte field containing the mobile router's IPv6 Home Mobile Network Prefix. Zhou, et al. Expires April 22, 2013 [Page 12] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 5. Security Considerations This document describes extensions to the Proxy Mobile IPv6 protocol for supporting network mobility using DHCPv6-based Prefix Delegation. The security considerations for DHCPv6 described in the "Security Considerations" section of the DHCPv6 base specification [RFC3315], the "Security Considerations" of the DHCPv6 Prefix Delegation specification [RFC3633], and the security considerations from the base Proxy Mobile IPv6 [RFC5213] apply when using the extensions defined in this document. The use of DHCPv6, as described in this document, requires message integrity protection and source authentication. The IPsec security mechanism mandated by Proxy Mobile IPv6 [RFC5213] SHOULD be used to secure the DHCPv6 signaling between the mobile access gateway and the local mobility anchor. In the following, we describe the Security Policy Database (SPD) and Security Association Database (SAD) entries necessary to protect the DHCPv6 signaling. We use the same format used by [RFC4877]. The SPD and SAD entries are only example configurations. A particular mobile access gateway implementation and a local mobility anchor implementation could configure different SPD and SAD entries as long as they provide the required security of the DHCPv6 signaling messages. For the examples described in this document, a mobile access gateway with address "mag_address_1", and a local mobility anchor with address "lma_address_1" are assumed. mobile access gateway SPD-S: - IF local_address = mag_address_1 & remote_address = lma_address_1 & proto = UDP & local_port = any & remote_port = DHCP Then use SA1 (OUT) and SA2 (IN) mobile access gateway SAD: - SA1(OUT, spi_a, lma_address_1, ESP, TRANSPORT): local_address = mag_address_1 & remote_address = lma_address_1 & proto = UDP & remote_port = DHCP - SA2(IN, spi_b, mag_address_1, ESP, TRANSPORT): local_address = lma_address_1 & remote_address = mag_address_1 & proto = UDP & local_port = DHCP local mobility anchor SPD-S: - IF local_address = lma_address_1 & remote_address = mag_address_1 & proto = UDP & local_port = DHCP & remote_port = any Zhou, et al. Expires April 22, 2013 [Page 13] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 Then use SA2 (OUT) and SA1 (IN) local mobility anchor SAD: - SA2(OUT, spi_b, mag_address_1, ESP, TRANSPORT): local_address = lma_address_1 & remote_address = mag_address_1 & proto = UDP & local_port = DHCP - SA1(IN, spi_a, lma_address_1, ESP, TRANSPORT): local_address = mag_address_1 & remote_address = lma_address_1 & proto = UDP & remote_port = DHCP Zhou, et al. Expires April 22, 2013 [Page 14] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 6. IANA Considerations This document defines a new mobility option that require IANA actions. Zhou, et al. Expires April 22, 2013 [Page 15] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 7. Acknowledgments The work of Carlos J. Bernardos has also been partially supported by the European Community's Seventh Framework Programme (FP7-ICT-2009-5) under grant agreement n. 258053 (MEDIEVAL project) and by the Ministry of Science and Innovation of Spain under the QUARTET project (TIN2009-13992-C02-01). Zhou, et al. Expires April 22, 2013 [Page 16] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2890] Dommety, G., "Key and Sequence Number Extensions to GRE", RFC 2890, September 2000. [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. [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, December 2003. [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005. [RFC4877] Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation with IKEv2 and the Revised IPsec Architecture", RFC 4877, April 2007. [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008. [RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC 6275, July 2011. [RFC6276] Droms, R., Thubert, P., Dupont, F., Haddad, W., and C. Bernardos, "DHCPv6 Prefix Delegation for Network Mobility (NEMO)", RFC 6276, July 2011. [RFC6603] Korhonen, J., Savolainen, T., Krishnan, S., and O. Troan, "Prefix Exclude Option for DHCPv6-based Prefix Delegation", RFC 6603, May 2012. 8.2. Informative References [RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology", RFC 3753, June 2004. Zhou, et al. Expires April 22, 2013 [Page 17] Internet-Draft Prefix Delegation for Proxy Mobile IPv6 October 2012 Authors' Addresses Xingyue Zhou ZTE Corporation No.50 Software Avenue, Yuhuatai District Nanjing China Phone: +86-25-8801-4634 Email: zhou.xingyue@zte.com.cn Jouni Korhonen Nokia Siemens Networks Linnoitustie 6 Espoo FIN-02600 Finland Email: jouni.nospam@gmail.com Carl Williams Consultant San Jose, CA USA Email: carlw@mcsr-labs.org Sri Gundavelli Cisco 170 West Tasman Drive San Jose, CA 95134 USA Email: sgundave@cisco.com Carlos J. Bernardos Universidad Carlos III de Madrid Av. Universidad, 30 Leganes, Madrid 28911 Spain Phone: +34 91624 6236 Email: cjbc@it.uc3m.es URI: http://www.it.uc3m.es/cjbc/ Zhou, et al. Expires April 22, 2013 [Page 18]