NETLMM Working Group Zhi-wei Yan Internet Draft Hong-ke Zhang Expires: January 2009 Hua-Chun Zhou Jian-Feng Guan Si-Dong Zhang Beijing Jiaotong University July 29, 2009 Consideration of Network Mobility in PMIPv6 draft-zhang-netlmm-nemo-00.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on January,2010. Copyright Notice Copyright (c) 2009 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract The NetLMM WG is specifying Proxy Mobile IPv6 (PMIPv6) for network- based localized mobility management (NetLMM), taking basic support for registration, de-registration and handover of signal Mobile Node (MN) into account in the RFC 5213 [1]. When a whole network moves into the PMIPv6 domain through the Mobile Router (MR), the scheme should be considered to provide and maintain the connectivity for the Mobile Network Node (MNN) in the mobile network (NEMO). This document discusses the deployment consideration of NEMO support in PMIPv6 network and proposes the possible solution accordingly. Zhang et al. Expires January 1, 2010 [Page 1] Internet-Draft Consideration of NEMO in PMIPv6 July 2009 Conventions used in this document 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 [1]. Table of Contents 1. Introduction...................................................1 2. Problem statement of NEMO in PMIPv6 network....................2 3. Possible solution for the NEMO in PMIPv6 network...............2 4. Possible solution for the nested NEMO in PMIPv6 network........3 5. Requirements of the newly defined messages.....................4 6. Security Considerations........................................4 7. References.....................................................4 Authors' Addresses................................................5 1. Introduction As the extension of basic MIPv6 specification [2], NEMO [3] was proposed to support the network mobility in MIPv6 network. The protocol procedure of MIPv6-NEMO is compatible with basic MIPv6 protocol and the prefix of network is maintained by HA to support the redirection of packets to and from the mobile network. However, the mobility of MIPv6-NEMO is managed by the MR as the MN does in basic MIPv6. Be different with MIPv6, the PMIPv6 was proposed to support the network-based mobility supporting. The entities in the PMIPv6 have the responsibility to track the MN, update the location of MN and redirect the packets to and from MN. However, the basic PMIPv6 protocol only consider the mobility management for the signal MN, the mobility supporting for a whole network is not considered. This document discusses the deployment consideration of NEMO in PMIPv6 network noted as PMIPv6-NEMO. As a default router of the whole mobile network, a PMIPv6-MR should not only send and receive the packets for MNN, but also manage the mobility of MNN. Zhang et al. Expires January 1, 2010 [Page 2] Internet-Draft Consideration of NEMO in PMIPv6 July 2009 2. Problem statement of NEMO in PMIPv6 network At least there are two problems should be considered when deploying NEMO in PMIPv6 network. The first one is the mobility management of the whole network. The second one is the nested NEMO supporting consideration. For the first problem, the binding process and packets interception scheme of basic PMIPv6 must be extended to manage the MR and its related Mobile Network Prefix (MNP). The Local Mobility Anchor (LMA) must not only intercept and redirect the packets for MR, but also intercept and redirect the packets for the nodes belonging to the MNP. For the second problem, we should consider who manages the mobility of NEMO. When the mobility of NEMO is managed by MR itself, it follows the procedure in RFC 3963 and the advantages of network-based manner disappear. When the mobility of NEMO is managed by network, the MR should not involve in the mobility management process. Then the mobility of nested MRs should also be managed by network and not the MRs themself. 3. Possible solution for the NEMO in PMIPv6 network In PMIPv6, the MN-HNP is a prefix assigned to the link between the mobile node and the Mobile Access Gateway (MAG). More than one prefix can be assigned to the link between the mobile node and the mobile access gateway, in which case, all of the assigned prefixes are managed as a set associated with a mobility session. The mobile node configures its interface with one or more addresses from its home network prefix(es). After the first binding process between MAG and LMA, the address of MN remains when MN roams in the same PMIPv6 domain. The address of currently attached MAG is the Proxy Care-of Address (Proxy-CoA) of MN. The mapping information of MN' prefix and Proxy-CoA is maintained and updated by LMA. When the NEMO is deployed, the binding process must be extended. The indication information of MR' access should be carried in the PBU and PBA messages. Besides, the following information must be maintained by LMA in the binding cache entries. o R flag indicating whether or not this Binding Cache entry is created for a mobile router or a signal node. This flag is set to value 1 for Binding Cache entries for MRs and is set to value 0 for the signal nodes. o A list of IPv6 mobile network prefixes in the mobile network. The mobile network prefix(es) may have been statically configured in the Zhang et al. Expires January 1, 2010 [Page 3] Internet-Draft Consideration of NEMO in PMIPv6 July 2009 mobile router's policy profile, or, they may have been dynamically allocated by the LMA. Each one of these prefix entries will also include the corresponding prefix length. 4. Possible solution for the nested NEMO in PMIPv6 network The Router Advertisement message must be sent out by the MR in the point-to-point manner as the MAG does. When another MR2 or MN attaches to the MR1 whose connection has been established, the attachment should be discovered by MR1 through the Link layer information. But the MR1 should not involve in the mobility management process as MAG does. In the process of PMIPv6, the MAG who discovers the attachment of MN will authenticate the MN and require its related information, such as the MN' identifier and its LMA address. Then the MAG initiates the binding process to establish a tunnel with the LMA for the MN. In the PMIPv6-NEMO, the authentication and binding process should be triggered by the attached MR and executed by the MAG attached by root MR. The process is illustrated in figure 1. +------+ +-----+ +-----+ +-----+ | MR2 | | MR1 | | MAG | | LMA | +------+ +-----+ +-----+ +-----+ |-- Attach ->| | | |--RtSol---->| | | | |----PAQ--->| | | | |------PBU--->| | | | Accept PBU | | (Allocate MR-HNP(s), Setup BCE and Tunnel) | | | | | | |<-----PBA----| | |<----PAP---| | |<----RA-----| | | |-----data-->| | | | |----data-->| | | | |====data====>| | | |<====data====| | |<----data--| | |<-----data--| | | | | | | Figure 1: Solution for nested NEMO There are two newly defined signaling messages: PAQ is the Proxy Authentication Request message sent by the attached MR to the upper Zhang et al. Expires January 1, 2010 [Page 4] Internet-Draft Consideration of NEMO in PMIPv6 July 2009 layer MR or the MAG, PAP is the Proxy Authentication Reply message which is the response message of PAQ. When the MR1 attaches to the MAG, a tunnel is established for MR1 between MAG and LMA. When another MR2 attaches to MR1, the MR1 sends out the PAQ message to MAG and the MAC address of MR2 is carried in PAQ. Then the MAG authenticates the MR2 and sends out the PBU message to the LMA of MR2 as illustrated in section 3. When the LMA receives the PBU message, it establishes a tunnel with MAG and sends back the PBA message. After this process, the tunnel is established for MR2 and the MAG sends a PAP message to MR1 which is the response message to PAQ. When the PAP message arrives at MR1, the proper policy is established and the following packets to and from MR2 can be redirected by MR1. 5. Requirements of the newly defined messages In the newly defined PAQ and PAP messages, some necessary information must be carried. In the PAQ message, only the MAC address of MNN should be carried. While in the PAP message, the following information should be carried, o R flag indicating whether or not this authentication is executed for a mobile router or a signal node. This flag is set to value 1 for for MRs and is set to value 0 for the signal nodes. o A list of IPv6 Home Network Prefixes(HNP). The home network prefix(es) may have been statically configured for the mobile router, or, they may have been dynamically allocated by the local mobility anchor. Each one of these prefix entries will also include the corresponding prefix length. 6. Security Considerations The HNP of the nested MR may be different with the prefix the attached MR broadcasts. So the attached MR must check whether the packets belong to the MNN in its mobile network. To eliminate the threats on the interface between the mobile access gateway and the MR, this specification requires an established trust between the mobile access gateway and the MR node and to authenticate and authorize the MR before it is allowed to access the network. 7. References [1] Gundavelli, et al., "Proxy Mobile Ipv6", RFC5213, August 2008. Zhang et al. Expires January 1, 2010 [Page 5] Internet-Draft Consideration of NEMO in PMIPv6 July 2009 [2] David B. Johnson, Charles E. Perkins and Jari Arkko. "Mobility Support in IPv6", RFC 3775, June 2004. [3] Vijay Devarapalli, Ryuji Wakikawa, Alexandru Petrescu, and Pascal Thubert. "NEMO Basic Support Protocol", RFC 3963, January 2005. Author's Addresses Zhi-Wei Yan , Hong-Ke Zhang,Hua-Chun Zhou, Jian-Feng Guan, Si-Dong Zhang NGI Research Center Beijing Jiaotong University of China Phone: +861051685677 Email:06120232@bjtu.edu.cn hkzhang@bjtu.edu.cn hchzhou@bjtu.edu.cn guanjian8632@163.com sdzhang@center.njtu.edu.cn