Network Working Group Seil Jeon Internet-Draft Soongsil University, Korea Expires: April 24, 2010 Younghan Kim Soongsil University, Korea October 24, 2009 Mobile Multicasting Support in Proxy Mobile IPv6 draft-sijeon-multimob-mms-pmip6-01.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/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 24, 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. Jeon, et al. Expires April 24, 2010 [Page 1] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 Abstract To support IP-based group communication such as mobile IPTV in mobile environment, IP multicasting is required. For minimized burden and modification on PMIPv6 components, multicasting architecture is required to determine where to locate the multicast router (MR) and how to operate IGMP/MLD action in PMIPv6 network. To deploy PMIPv6 multicasting, there are two possible approaches: tunnel forwarding and direct routing scenario. But, this draft focuses direct routing scenario based PMIPv6 multicasting architecture that do not require MR function within the LMA and handover mechanism and describes IGMP/MLD operation. Our solution is easy to deploy and save bandwidth usage. And it solves the tunnel convergence problem without PMIPv6 modification. Table of Contents 1. Introduction.....................................................3 2. Terminology and Functional Components............................4 3. Tunnel Forwarding Model..........................................5 4. Direct Routing Model.............................................5 4.1. Architecture.................................................5 4.2. Handover Operation...........................................7 5. Message Header...................................................9 5.1. MLD Query....................................................9 5.2. MLD Report...................................................9 5.3. Multicast Packet.............................................9 6. IANA Considerations.............................................10 7. Security Considerations.........................................10 8. References......................................................10 8.1. Normative References........................................10 8.2. Informative References......................................11 Author's Address...................................................12 Jeon, et al. Expires April 24, 2010 [Page 2] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 1. Introduction High performance of wireless technologies make multimedia streaming services possible, such as IPTV audio/video stream. These services are based on group communication, and IP multicasting is also required. Traditional IP multicast mechanisms, including multicast routing and membership management protocols, have been designed for static hosts [RFC2710][RFC3810]. Moreover, up to now, IP mobility protocol for mobile multicasting has depended on host-based Mobile IP variants (Mobile IP and Fast Mobile IPv6). However, the protocols require modifications to an applied solution on mobile device, as well as IP reconfiguration during handoff. The Proxy Mobile IPv6 (PMIPv6) in [RFC5213] does not require any mobility-related protocol, and IP reconfiguration in the same PMIPv6 domain. However, [RFC5213] is only targeting unicasting-based mobility management architecture and operation. To support PMIPv6 multicasting service, we need the solution to determine which PMIPv6 component should be operated as multicast router (MR). As a first step, if a MAG has an MR function, a LMA needs to have MR function. Then, the routing update overhead degrades the performance of PMIPv6 components due to the frequent movement of the MNs. Second, we can consider MR co-located LMA model that only LMA has an MR function and a MAG has IGMP/MLD forwarding. It has less complexity than former case. But, both cases introduce the tunnel convergence problem which wastes bandwidth and high handover latency. For minimized burden of multicasting operation for PMIPv6 components and tunnel convergence problem, we designed PMIPv6 multicasting solution using direct routing which local multicast router delivers multicast packets to the MAG based on multicast support scenario in [I-D.deng-multimob-pmip6-requirement]. In our solution, a MAG is operated as MLD forwarding proxy function using the IGMP/MLD forwarding proxy [RFC4605] presented by the IETF. Jeon, et al. Expires April 24, 2010 [Page 3] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 2. Terminology and Functional Components 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] o Mobile Node (MN) o Previous Mobile Access Gateway (P-MAG) - The MAG that manages mobility relaged signaling for a MN before handover. In this document, a MAG and Access Router (AR) are collocated o New Mobile Access Gateway (N-MAG) - The MAG that manages mobility related signaling for the MN after handover o Multicast Router (MR) o MLD Forwarding Proxy (MF-Proxy) o PMIPv6 Multicast Context Transfer (MCT) - It is transmitted by P- MAG forecasting MN's destination N-MAG. This message include MN ID, MN home network prefix and P-MAG IP address, and multicast group address of the MN executing handoff. Jeon, et al. Expires April 24, 2010 [Page 4] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 3. Tunnel Forwarding Scenario In this draft, a tunnel forwarding scenario means that only LMA has a MR function and a MAG has IGMP/MLD forwarding function. To transfer multicast data between MAG and LMA, PMIPv6 tunnel is used. However, this scenario introduces tunnel convergence problem because each MAG is connected to several LMAs. So, same tunneling packets from several LMAs is converged into a certain MAG. 4. Direct Routing Scenario 4.1. Architecture Multicast Tree : : || - PMIPv6 Tunnel +----------+ +----------+ | - Multicast Data Path | LMA | | Local MR | +----------+ +----------+ ||\\ /| || \\ / | || \\ / | || \\ / | || \\/ | || / \\ | || / \\ | || / \\ | +----------+ +----------+ | P-MAG | | N-MAG | |(MF-Proxy)| |(MF-Proxy)| +----------+ +----------+ : : +------+ +------+ | MN | -----> | MN | +------+ +------+ Figure 1. Direct Routing Scenario for PMIPv6 Multicasting Figure 1 shows the proposed direct routing scenario for PMIPv6 multicasting. There is no multicast routing function on the LMA. We Jeon, et al. Expires April 24, 2010 [Page 5] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 call it direct routing scenario that is based on local routing scenario described in [I-D.deng-multimob-pmip6-requirement]. This solution can minimize PMIPv6 modification and solve tunnel convergence issue caused by a MAG receives same multicast packets from several LMAs. To relay IGMP/MLD signaling and multicast packets, a MAG needs only MLD forwarding proxy function defined in [RFC4605]. Our solution has more simple structure than tunnel forwarding scenario and easy to deploy because a LMA is separated from multicast operation. Jeon, et al. Expires April 24, 2010 [Page 6] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 4.2. Handover Operation Multicast MN P-MAG N-MAG LMA MR Tree | | | | | | | | | | | | |<----------|<-- MLD Query ------------------| | | | . | | | | | | . | | | | | | . | | | | Link->| Handover | | | | Disconnected Detection | | | | | | | | | | | |--PMIPv6-->| | | | | | Multicast | | | | | | Context | | | | | | Transfer | | | | | | | | | | | | |---- MLD Report --->| | | | | | | | |---- L2 Attachment --->| | | | | | | | | | | | | Proxy | | | | | |--Binding->| | | | | | Update | | | | | | | | | | | | | | | | | |<--Proxy --| | | | | | Binding | | | | | | Ack. | | | | | | | | | | | | | | | |<----------------------|<-- Multicast Data--|<-------| | | | | | | Figure 2. Handover Operation in Direct Routing Scenario Directly applying a PMIPv6 handover scheme to the proposed scenario, it leads to service disruption due to the latency caused by the IGMP/MLD action [IP-MM]. To solve this problem, we utilized the context transfer mechanism for seamless handover. Figure 2 shows the handover operation. When an MN hands off, the MAG with the MLD Jeon, et al. Expires April 24, 2010 [Page 7] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 forwarding proxy predicts an MN's movement direction and transfers the multicast context message, which includes the MN ID, the MN home network prefix, the current MAG address, and the multicast group address. The N-MAG then checks whether it is receiving a node of multicast data corresponding to the group requested by the P-MAG. If this is not the case, it joins the group by sending an MLD report to the local MR. Then, local MR delivers the multicast packets to the N- MAG regardless there is a receiving node or not for designated time. If the MN does not arrive at the N-MAG until the timer for specific channel expired, the N-MAG sends a MLD report to the MR for channel leave. When a MAG receives the multicast packets, it simply forwards the packets without tunnel encapsulation. Jeon, et al. Expires April 24, 2010 [Page 8] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 5. Message Formats This section describes source and destination address of MLD signaling messages. The interface A-B means that an interface on node A, which is connected to node B. 5.1. MLD Query +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Interface | Source Address | Destination Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MR-MAG | MR link local | [RFC2710], [RFC3810] | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAG-MN | MAG link local | [RFC2710], [RFC3810] | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5.2. MLD Report +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Interface | Source Address | Destination Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MN-MAG | MN link local | [RFC2710], [RFC3810] | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAG-MR | MAG link local | [RFC2710], [RFC3810] | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5.3. Multicast Packets +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Interface | Source Address | Destination Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MR-MAG | Streaming Source Addr. | Multicast Group Addr. | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAG-MN | Streaming Source Addr. | Multicast Group Addr. | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Jeon, et al. Expires April 24, 2010 [Page 9] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 6. IANA Considerations TBD. 7. Security Considerations This document does not discuss any special security concerns in detail. The protocol of this document is built on the assumption that all participating nodes are trusted each other as well as there is no adversary who modifies/injects false messages to corrupt the procedures. 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. [RFC2710] S. Deering, W. Fenner, B. Harberman, "Multicast Listener Discovery (MLD) for IPV6," IETF RFC 2710, October 1999. [RFC3810] R. Vida, and L. Costa, "Multicast Listener Discovery Version(MLDv2) for IPv6," IETF RFC 3810, June 2004. [RFC5213] S. Gundavelli, K. Leung, V. Devarapalli, K. Chowdhury, and B. Patil, "Proxy Mobile IPv6", IETF RFC 5213, Augurst 2008. [RFC4605] B. Fenner, H. He, B. Haberman, and H. Sandick, "Internet Group Management Protocol (IGMP) / Multicast Listener Discovery (MLD)-Based Multicast Forwarding ("IGMP/MLD Proxying")", IETF RFC 4605, August 2006. [I-D.deng-multimob-pmip6-requirement] H. Deng, T. Schmidt, P. Seite, and P. Yang, "Multicast Support Requirements for Proxy Mobile IPv6," draft-deng- multimob-pmip6-requirement-01.txt (work in progress), October 2008. Jeon, et al. Expires April 24, 2010 [Page 10] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 8.2 Informative References [IP-MM] I. Romdhani, M. Kellil, and H. Lach, "IP Mobile Multicast : Challenges and Solutions," IEEE Communications Surveys & Tutorials, vol. 6, no. 1, pp. 18-41, 2004. [PMIPv6-MS] Seil Jeon, Namhi Kang, and Younghan Kim, "Mobility Management based on Proxy Mobile IPv6 for Multicasting Services in Home Networks," IEEE Transactions on Consumer Electronics, vol. 5, no. 3, pp. 1227-1232, August 2009. Jeon, et al. Expires April 24, 2010 [Page 11] Internet-Draft Mobile Multicasting Support in PMIPv6 October 2009 Author's Addresses Seil Jeon Soongsil University 11F Hyungnam Engineering Bldg. 317, Sangdo-Dong, Dongjak-Gu, Seoul 156-743 Korea Phone: +82 2 814 0151 E-mail: sijeon@dcn.ssu.ac.kr Younghan Kim Soongsil University 11F Hyungnam Engineering Bldg. 317, Sangdo-Dong, Dongjak-Gu, Seoul 156-743 Korea Phone: +82 2 820 0904 E-mail: yhkim@dcn.ssu.ac.kr Jeon, et al. Expires April 24, 2010 [Page 12]