16ng BoF S. Jeong Internet-Draft ETRI Expires: August 29, 2006 H. Jang SAIT February 25, 2006 IPv6 Multicast Packet Delivery over IEEE 802.16 Networks draft-jeong-16ng-multicast-delivery-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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 August 29, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This memo describes transmission of IPv6 multicast packets over IEEE 802.16 networks, including the methods to deliver various scoped multicast packets. It also presents the methods of forming multicast CIDs on IEEE 802.16 networks. Jeong & Jang Expires August 29, 2006 [Page 1] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Assumption and Scope . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology and Abbreviations . . . . . . . . . . . . . . 4 2. Brief Description of Subnet Models . . . . . . . . . . . . . . 5 3. Subnet Model A . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1. Link Local scope Multicast Packet . . . . . . . . . . . . 6 3.2. Non-link Local scope Multicast Packet . . . . . . . . . . 6 4. Subnet Model B . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1. Link Local scope Multicast Packet . . . . . . . . . . . . 8 4.2. Non-link Local scope Multicast Packet . . . . . . . . . . 8 5. Subnet Model C . . . . . . . . . . . . . . . . . . . . . . . . 10 5.1. Link Local scope Multicast Packet . . . . . . . . . . . . 10 5.2. Non-link Local scope Multicast Packet . . . . . . . . . . 10 6. Subnet Model D . . . . . . . . . . . . . . . . . . . . . . . . 12 6.1. Link Local scope Multicast Packet . . . . . . . . . . . . 12 6.2. Non-link Local scope Multicast Packet . . . . . . . . . . 13 7. Considerations about MCID Format . . . . . . . . . . . . . . . 14 7.1. IPv6 scope-based MCID Format . . . . . . . . . . . . . . . 14 7.2. Distributed Link Local Multicast CID Format . . . . . . . 14 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 9. Security Considerations . . . . . . . . . . . . . . . . . . . 16 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18 Intellectual Property and Copyright Statements . . . . . . . . . . 19 Jeong & Jang Expires August 29, 2006 [Page 2] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 1. Introduction IEEE 802.16 networks support mobile stations (MSs) to access broadband wireless networks while moving at a vehicular speed [IEEE802.16e]. However, 802.16 networks do not provide link layer native multicast capability because of point-to-multipoint connection characteristic [IEEE802.16]. This feature restricts the adoption of protocols or applications that need IPv6 multicast capability. One of the prominent ways to solve the multicast support problem is to use the built-in LAN emulation feature of 802.16 which is based on Convergence Sublayer [I-D.jee-16ng-problem-statement]. There are several previous work that focused on the transport of link local scope multicast packets over 802.16 network [I-D.jeon-ipv6-ndp- ieee802.16][I-D.jang-16ng-llm]. However, the IPv6 multicast service requires not only the delivery of link local scope multicast packets, but also the delivery of non-link local scope multicast packets such as site local or global scope multicast packets. Since it is unclear for 802.16 networks what constitutes a subnet, we need to consider the transport of IPv6 multicast packets over various subnet models [I-D.madanapalli-nd-over-802.16-problems]. This memo describes how the IPv6 multicast packets with various scope can be delivered over four different types of subnet models. 1.1. Assumption and Scope This document describes how to provide IP CS based IPv6 multicast packets delivery over IEEE 802.16 networks. We will consider Ethernet CS based IPv6 multicast packet transport in the later version of this document. We classify the IPv6 multicast packet into link local scope and non- link local scope multicast packet. Node-local scope multicast packet is not considered in this memo. When a BS is separated from an access router (AR), we assume that the BS is connected to AR via Ethernet. If Ethernet is not used between BS and AR, tunneling may be used to apply our proposed approaches. Our approaches are based on the use of multicast CID (MCID) to distinguish between multicast and unicast packets, and to deliver the multicast packets. This memo presents MCID based transport of IPv6 multicast packet not only link local scope, but also non-link local scope. The initialization or distribution of MCID is not covered in this document, but we may guess that the MCID will be initialized during the establishment phase of host IP connectivity. Jeong & Jang Expires August 29, 2006 [Page 3] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 1.2. Terminology and Abbreviations In this memo, a link local multicast packet indicates a multicast packet with link local scope such as NS, RA, and so on. A non-link local multicast packet means that scope of the packet is neither node local nor link local. The non-link local multicast packet also includes a multicast data packet. AR (access router) BS (base station) CID (connection id) CS (convergence sublayer) MCID (multicast CID) : CID for IP multicast service MS (mobile station) Jeong & Jang Expires August 29, 2006 [Page 4] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 2. Brief Description of Subnet Models The relationship between BS and AR induces several IP subnet models in 802.16 networks. We may deduce following four IP subnet models from the IP prefix assignment method and the relationship of AR and BS [I-D.shin-v6ops-802.16-deployment-scenarios]. This document describes the transport of IPv6 multicast packets with IP CS over each subnet models. +--------+---------------------------+----------------------------+ | Subnet | Deployment architecture | Subnet components | | model | | | +--------+---------------------------+----------------------------+ | A | BS and AR are in same box | Single BS/AR, single MS | +--------+---------------------------+----------------------------+ | B | BS and AR are in same box | Single BS/AR, multiple MSs | +--------+---------------------------+----------------------------+ | C | BS is separated from AR | Single BS, single router, | | | | multiple MSs | +--------+---------------------------+----------------------------+ | D | BS is separated from AR | Multiple BSs, multiple MSs | +--------+---------------------------+----------------------------+ Figure 1: IP subnet models in 802.16 networks Jeong & Jang Expires August 29, 2006 [Page 5] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 3. Subnet Model A When BS and AR are integrated in the same box, there exist two cases of IPv6 prefix allocation method. The one is to assign an IPv6 prefix to each AR/BS box and the other is to allocate an IPv6 prefix to each MS, similar to 3GPP scenario [RFC 3314]. In this section, we discuss the delivery of IPv6 multicast packets over 'Subnet model A' depicted in Figure 2 where a BS is integrated with a router, composing one box in view of implementation. In this subnet model, each subnet consists of single BS/AR and only one MS. Thus, each MS has a unique IPv6 prefix. +-----+ | MS1 |<-------------+ +-----+ v +-----+ +-------+ +--------+ | MS2 |<---------->|BS/AR1 |---------| Edge | ISP +-----+ +-------+ | Router +==>Network +--------+ +-----+ +-------+ | | MS3 |<---------->|BS/AR2 |-----------+ +-----+ +-------+ <---> IP termination Figure 2: Subnet model A 3.1. Link Local scope Multicast Packet Since one MS exists in a subnet and the MS gets a unique IPv6 prefix, it is not needed to transmit IPv6 multicast packet by using MCID. A multicast packet sent from MS may be delivered to BS/AR by using unicast CID. BS/AR may transmit a multicast packet to MS by using unicast CID. 3.2. Non-link Local scope Multicast Packet There are two types of non-link local scope multicast packets, originated from MS and originated from other subnets or Internet. In both types, BS/AR should support both MLDv2 [RFC 3810] and IPv6 multicast routing protocols. 3.2.1. Non-link Local Multicast Packet from MS In the Figure 2, when BS/AR1 receives a non-link local scope multicast packet from MS1, BS/AR1 looks up the multicast routing table and forwards the packet to the edge router according to lookup result. The packet forwarded by BS/AR1 is delivered to edge router Jeong & Jang Expires August 29, 2006 [Page 6] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 or BS/AR2 by means of regular IPv6 multicast packet transport procedure. If the packet is destined to BS/AR2's subnet, BS/AR2 transmits the packet to its downlinks with unicast CID. 3.2.2. Non-link Local Multicast Packet from Other Subnets or Internet When BS/AR receives a multicast packet from edge router, it looks up the multicast routing table and checks whether the packet is destined to its own subnet. If there exists a receiver in the subnet, BS/AR forwards the packet to its downlinks by using unicast CID. Jeong & Jang Expires August 29, 2006 [Page 7] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 4. Subnet Model B In this section, we discuss the delivery of IPv6 multicast packets over 'Subnet model B' depicted in Figure 3 where a BS is integrated with a router, composing one box, and a subnet consisting of only single BS/AR and multiple MSs. +-----+ | MS1 |<------+ +-----+ | +-----+ | +-------+ +--------+ | MS2 |<------+--->|BS/AR1 |---------| Edge | ISP +-----+ +-------+ | Router +==>Network +--------+ +-----+ +-------+ | | MS3 |<---------->|BS/AR2 |-----------+ +-----+ +-------+ <---> IP termination Figure 3: Subnet model B 4.1. Link Local scope Multicast Packet Link local scope multicast packets may be classified by packets originated from MS and from BS/AR integrated box. 4.1.1. Link Local Multicast Packet from MS In the Figure 3, when BS/AR1 receives a link local scope multicast packet from MS1, BS/AR1 multicasts the packet onto its downlinks by using MCID. 4.1.2. Link Local Multicast Packet from BS/AR When BS/AR needs to send a multicast packet to MSs in the subnet, BS/AR transmits the packet to its downlinks with MCID. 4.2. Non-link Local scope Multicast Packet There are two types of non-link local scope multicast packets, originated from MS and from other subnets or Internet. In both types, BS/AR should support both MLDv2 and IPv6 multicast routing protocols. 4.2.1. Non-link Local Multicast Packet from MS In the Figure 3, when MS1 sends a non-link local scope multicast packet, BS/AR1 receives the packet and transmits the packet to its Jeong & Jang Expires August 29, 2006 [Page 8] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 downlinks by using MCID. After then, BS/AR1 looks up the multicast routing table and forwards the packet to the edge router according to the lookup result. The packet forwarded by BS/AR1 is delivered to BS/AR2 or edge router by means of regular IPv6 multicast packet transport procedure. If the packet is destined to BS/AR2's subnet, BS/AR2 transmits the packet to its downlinks with MCID. 4.2.2. Non-link Local Multicast Packet from Other Subnets or Internet When BS/AR receives a multicast packet from edge router, it looks up the multicast routing table and checks whether the packet is destined to its own subnet. If there exists a receiver in the subnet, BS/AR sends the packet to its downlinks by using MCID. Jeong & Jang Expires August 29, 2006 [Page 9] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 5. Subnet Model C In this section, we discuss the transport of IPv6 multicast packets over the 'Subnet model C' shown in Figure 4 where a BS is separated from an AR and a subnet consists of multiple BSs and multiple MSs. +-----+ | MS1 |<------+ +-----+ | +-----+ | +-----+ +-----+ +--------+ | MSs |<------+----| BS1 |---->| AR |----| Edge | ISP +-----+ +-----+ +-----+ | Router +==>Network ^ +--------+ +-----+ +-----+ | | Mss |<-----------| BS2 |--------+ +-----+ +-----+ <---> IP termination Figure 4: Subnet model C 5.1. Link Local scope Multicast Packet Link local scope multicast packets may be classified by packets originated from MS and from AR. 5.1.1. Link Local Multicast Packet from MS In the Figure 4, when BS1 receives a link local scope multicast packet originated from MS1, BS1 multicasts the packet onto its downlinks by using MCID. After then, BS1 converts the IEEE 802.16 MAC frame format to IEEE 802.3 Ethernet frame and transmits the frame into the link connected to AR. 5.1.2. Link Local Multicast Packet from AR When BS receives an Ethernet frame sent from AR, it examines the IPv6 destination address. If the destination address is link local scope multicast address, BS transmits the packet to its downlinks with MCID. 5.2. Non-link Local scope Multicast Packet Non-link local scope multicast packets can be classified into two cases, packets sent from MS and sent from other subnets in the same site or Internet. In both cases, AR should support both MLDv2 and IPv6 multicast routing protocols. Jeong & Jang Expires August 29, 2006 [Page 10] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 5.2.1. Non-link Local Multicast Packet from MS In the Figure 4, when MS1 sends a non-link local scope multicast packet, BS1 performs the same operation as link local scope case. When AR receives the packet transmitted by BS1, it performs the multicast routing table lookup and forwarding. The packet forwarded by AR is delivered to BS2 or edge router according to regular IPv6 multicast packet transport procedure. If the packet is destined to MSs in BS2's subnet, BS2 transmits the received packet to its downlinks with predefined MCID. 5.2.2. Non-link Local Multicast Packet from Other Subnets or Internet When AR receives a packet from edge router, it looks up the multicast routing table and checks whether there exists a receiver of the packet in AR's subnets. If there exists a receiver, AR sends the packet to appropriate BSs in the downlinks. When BS receives the multicast packet sent from AR, it checks the IPv6 destination address. If the destination address is non-link local scope multicast address, BS multicasts the packet to its downlinks with MCID. Jeong & Jang Expires August 29, 2006 [Page 11] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 6. Subnet Model D In this section, we discuss the transport of IPv6 multicast packets over the 'Subnet model D' shown in the Figure 5 where a BS is separated from a router, and a subnet consists of multiple BS and multiple MSs. +-----+ +-----+ +-----+ ISP 1 | MS1 |<-----+ +->| AR1 |----| ER1 |===>Network +-----+ | | +-----+ +-----+ +-----+ | +-----+ | | MS2 |<-----+-----| BS1 |--| +-----+ +-----+ | +-----+ +-----+ ISP 2 +->| AR2 |----| ER2 |===>Network +-----+ +-----+ | +-----+ +-----+ | MS3 |<-----------| BS2 |--+ +-----+ +-----+ <---> IP termination Figure 5: Subnet model D 6.1. Link Local scope Multicast Packet Link local scope multicast packets may be classified by packets originated from MS and from AR. 6.1.1. Link Local Multicast Packet from MS In the Figure 5, when BS1 receives a link local scope multicast packet originated from MS1, BS1 multicasts the packet onto its downlinks by using MCID. After then, BS1 converts the IEEE 802.16 MAC frame format to IEEE 802.3 Ethernet frame and transmits the frame into the link connected to AR according to the destination address. BS2 which is on the same link as BS1, receives the Ethernet frame sent from BS1 and examines the IPv6 destination address. If the destination address is link local multicast address, BS2 multicasts the packet to its downlinks with predefined MCID. If the destination address is unicast, the received packet goes through IPv6 unicast packet handling process. 6.1.2. Link Local Multicast Packet from AR When BS receives an Ethernet frame sent from AR, it examines the IPv6 destination address. If the destination address is link local scope multicast address, BS transmits the packet to its downlinks with MCID. Jeong & Jang Expires August 29, 2006 [Page 12] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 6.2. Non-link Local scope Multicast Packet Non-link local scope multicast packets can be classified into two cases, packets sent from MS and sent from other subnets in the same site or Internet. In both cases, AR should support both MLDv2 and IPv6 multicast routing protocols. 6.2.1. Non-link Local Multicast Packet from MS In the Figure 5, when MS1 sends a non-link local scope multicast packet, BS1 and BS2 perform same operation as link local scope case. When AR1 receives the packet transmitted by BS1, it performs the multicast routing table lookup and forwarding. The packet forwarded by AR1 is delivered to AR2 or edge router according to regular IPv6 multicast packet transport procedure. If the packet is destined to AR2's subnet, AR2 transmits the packet to its downlinks. BS which is on the downlinks of AR2, receives the Ethernet frame sent from AR2 and examines the IPv6 destination address. If the destination address is link local multicast address, BS multicasts the packet to its downlinks with predefined MCID 6.2.2. Non-link Local Multicast Packet from Other Subnets or Internet When AR receives the packet from edge router, it looks up the multicast routing table and checks whether there exist receivers of the packet in AR's subnet. If there exists a receiver, AR sends the packet to BSs in the downlinks. Each BS in the subnet receives the packet sent from AR and checks the IPv6 destination address. If the destination address is non-link local scope multicast address, BS multicasts the packet to its downlinks with MCID. Jeong & Jang Expires August 29, 2006 [Page 13] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 7. Considerations about MCID Format The allocation of MCID to IPv6 multicast packets needs to be considered in IEEE. However, in this memo, we present a few candidates. 7.1. IPv6 scope-based MCID Format This section specifies a modification to the CID format as follows. | 11 | 1 | 4 | +------------------------------+---+----------+ | MCID prefix | M | scop | +------------------------------+---+----------+ Figure 6: IPv6 Scope based MCID Format MCID consists of MCID prefix, M, and scope field. MCID prefix is used to indicate that a multicast packet is embedded in IEEE 802.16 frame. M field implies that IP CS is used to encapsulate the IPv6 packet. When M field is 1, scope field be set to the same value as the scope field of encapsulated IPv6 destination address. When M field is 0, scope field is reserved for future use and should be 0. 7.2. Distributed Link Local Multicast CID Format This format is proposed in [I-D.jang-16ng-llm]. When IEEE 802.16 network interface is initialized, a MS generates a set of corresponding link local multicast CIDs by affixing well-known prefix n bit for IPv6 link local multicast, to the 16-n bit of the IPv6 multicast address. The well-known prefix will be allocated by IEEE later and 'n' will be decided with much consideration in later version. Jeong & Jang Expires August 29, 2006 [Page 14] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 8. IANA Considerations This document requests no action by IANA. Jeong & Jang Expires August 29, 2006 [Page 15] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 9. Security Considerations TBD 10. References [IEEE802.16] "IEEE 802.16-2004, IEEE standard for Local and metropolitan area networks, Part 16:Air Interface for fixed broadband wireless access systems", October 2004. [IEEE802.16e] "IEEE 802.16e/D10 Draft, IEEE Standard for Local and metropolitan area networks, Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems Amendment for Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands", August 2005. [I-D.jee-16ng-problem-statement] Jee, J., "16ng Problem Statement", draft-jee-16ng-problem-statement-02 (work in progress), October 2005. [I-D.jeon-ipv6-ndp-ieee802.16] Jeon, H. and J. Jee, "IPv6 NDP for Common Prefix Allocation in IEEE 802.16", draft-jeon-ipv6-ndp-ieee802.16-00 (work in progress), October 2005. [I-D.jang-16ng-llm] Jang, H., "Link-local Multicast Packet Transmission in 802.16 Networks", February 2006. [I-D.madanapalli-nd-over-802.16-problems] Madanapalli, S., "IPv6 Neighbor Discovery over 802.16: Problems and Goals", draft-madanapalli-nd-over-802.16-problems-00 (work in progress), December 2005. [I-D.shin-v6ops-802.16-deployment-scenarios] Shin, M-K., "ISP IPv6 Deployment Scenarios in Wireless Broadband Access Networks", February 2006. [RFC3314] Wasserman, M., "Recommendations for IPv6 in Third Generation Partnership Project (3GPP) Standards", RFC 3314, September 2002. Jeong & Jang Expires August 29, 2006 [Page 16] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 [RFC3810] Vida, R. and L. Costa, "Multicast Listener Discovery Version 2 (MLDv2) for IPv6", RFC 3810, June 2004. Jeong & Jang Expires August 29, 2006 [Page 17] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 Authors' Addresses Sangjin Jeong ETRI 161 Gajeong-dong, Yusung-gu Daejeon, 305-350 Korea Phone: +82 42 860 1877 Email: sjjeong@gmail.com Heejin Jang SAIT P.O. Box 111 Suwon 440-600 Korea Email: heejin.jang@samsung.com Jeong & Jang Expires August 29, 2006 [Page 18] Internet-Draft IPv6 Multicast over IEEE 802.16 February 2006 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Jeong & Jang Expires August 29, 2006 [Page 19]