Network Working Group M. Nam Internet-Draft E. Paik Expires: April 18, 2006 S. Kim S. Park Y. Park KT October 15, 2005 IPv6 Deployment Scenario over Mobile Broadband Wireless Networks draft-nam-ipv6-802-16e-00.txt 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 April 18, 2006. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document introduces a network structure for IEEE 802.16e, and IPv6 deployment scenario over IEEE 802.16e network with three phases. It lists considerations about mobility management aspect and network aspect that Internet Service Providers (ISPs) should consider when they start to provide IPv6 services. Nam, et al. Expires April 18, 2006 [Page 1] Internet-Draft IPv6 over IEEE 802.16e October 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Mobile Broadband Wireless Network Structure . . . . . . . . . 4 4. IPv6 deployment scenario over Mobile Broadband Wireless Access Network(IEEE 802.16e) . . . . . . . . . . . . . . . . . 5 4.1 Phase 1 . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2 Phase 2 . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.3 Phase 3 . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. Considerations . . . . . . . . . . . . . . . . . . . . . . . . 8 5.1 Mobility management aspect . . . . . . . . . . . . . . . . 8 5.2 Network aspect . . . . . . . . . . . . . . . . . . . . . . 9 6. Security considerations . . . . . . . . . . . . . . . . . . . 9 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 10 Intellectual Property and Copyright Statements . . . . . . . . 12 Nam, et al. Expires April 18, 2006 [Page 2] Internet-Draft IPv6 over IEEE 802.16e October 2005 1. Introduction New Mobile Broadband Wireless Access (MBWA) technology based on IEEE 802.16e has begun to attract much attention in industry. This is becoming a burning issue, and one of the key technologies which raises how to provide Internet access to mobile users. IEEE 802.16 specifies a new air interface and medium access control (MAC) protocol and provides high data rate as well as large cell coverage. In addition, IEEE 802.16e provides seamless mobility so that mobile users can use wireless Internet services while they are moving on vehicles. This document intruduces a network structure for IEEE 802.16e and IPv6 deployment scenario over the network structure. With the respect of Internet Service Providers (ISPs), this document describes requirements and considerations for deploying IPv6. It helps for enterprise administrators to refine their deployment scenarios and to make plans of deploying IPv6-based services. 2. Terminology This draft is based on the terminology defined in IEEE 802.16 and IEEE 802.16e . Subscriber station (SS): A generalized equipment set providing connectivity between subscriber equipment and a base station (BS). Mobile station (MS): A station in the mobile service intended to be used while in motion or during halts at unspecified points. A mobile station (MS) is always a subscriber station (SS) unless specifically excepted otherwise in this document. Base station (BS): A generalized equipment set providing connectivity, management, and control of the subscriber station (SS). A BS consists of one AR and several RASs. Nam, et al. Expires April 18, 2006 [Page 3] Internet-Draft IPv6 over IEEE 802.16e October 2005 AR: Access Router RAS: Radio Access Station ER: Edge router 3. Mobile Broadband Wireless Network Structure The network structure is shown in Fig. 1. Backbone Network consists of core routers, ERs, etc. A ER and a BS are connected directly. The BS consists of one AR and several RASs. Main functions of a BS are as follow: - Managing mobility of MS - Generating AAA information and sending them to AAA server - Supporting session connection, continuity and disconnection. These functions can be either handled in AR or in RAS according to implementation policy. Nam, et al. Expires April 18, 2006 [Page 4] Internet-Draft IPv6 over IEEE 802.16e October 2005 +----------------------------+ | BackBone | | Network | | +--+ +--+ | +-|ER|------------------|ER|-+ +--+ +--+ | | BS | | +--------------------+ +-------------------+ | +---+ | | +---+ | | |AR | | | |AR | | | +---+ | | +---+ | | / | \ | | / | \ | | / | \ | | / | \ | | / | \ | | / | \ | | +---+ +---+ +---+ | | +---+ +---+ +---+ | | |RAS| |RAS| |RAS| | | |RAS| |RAS| |RAS| | | +---+ +---+ +---+ | | +---+ +---+ +---+ | | | | | +--------------------+ +-------------------+ +--+ |MN|-----> ------> --------> +--+ Figure 1. Network Structure 4. IPv6 deployment scenario over Mobile Broadband Wireless Access Network(IEEE 802.16e) IPv6 service should be provided without affecting IPv4 service. An ISP can prepare IPv6 deployment by following three phases. 4.1 Phase 1 In phase 1, Mobile Broadband Wireless Access(MBWA) Internet Service is launched based on IPv4. While backbone network equipments (core routers, etc) support IPv4-only, new access network equipments (BSs and ERs) support IPv6 with dual stack. However dual stack in access network equipments is not enabled during phase 1. Tunneling protocol among ERs is defined but not be used. In this phase, the network delivers IPv4 traffic only. And MSs are based on IPv4. Nam, et al. Expires April 18, 2006 [Page 5] Internet-Draft IPv6 over IEEE 802.16e October 2005 +----------------------------+ | BackBone | | Network | --- tunneling protocol(disable) | +---+ +---+ | +-|ER |----------------|ER |-+ +---+ +---+ --- IPv4/IPv6 dual stack(disable) | | | | +-----+ +-----+ | BS | | BS | -- IPv4/IPv6 dual stack(disable) +-----+ +-----+ +--+ -- IPv4 |MN|-----> +--+ Figure 2. Phase 1 scenario 4.2 Phase 2 In phase 2, the ISP starts offering IPv6 service over MBWA. Access network equipments and ERs enable IPv4/IPv6 dualstack. IPv4 and IPv6 traffic is delivered independantly. IPv4 traffic is delivered as same as in phase 1. IPv6 traffic is delivered through tunnels between ERs in backbone network. because, core routers in the backbone network does not support IPv6. Before phase 2, mobility management protocol for IPv6 should be decided and be prepared for its requirements. - Link extention for Generic IP , Mobile IP, etc. - Home agent o Deployment or not o Requirements o Management of HAs We assume some MSs support IPv4/IPv6 dual stack. Nam, et al. Expires April 18, 2006 [Page 6] Internet-Draft IPv6 over IEEE 802.16e October 2005 +----------------------------+ | BackBone | | Network | --- tunneling protocol(enable) | +---+ +---+ | +-|ER |----------------|ER |-+ +---+ +---+ --- IPv4/IPv6 dual stack(enable) | | | | +-----+ +-----+ | BS | | BS | --- IPv4/IPv6 dual stack(enable) +-----+ +-----+ +--+ -- IPv4, IPv4/IPv6 dual stack |MN|-----> +--+ Figure 3. Phase 2 scenario 4.3 Phase 3 In phase 3, the ISP provides stable IPv6 service. Core routers in backbone network deliver IPv6 traffic without IPv4-IPv6 tunneling protocol. IPv4/IPv6 dual stack is enabled not only in edge routers but also in core routers. IPv4/IPv6 dual stack in BSs is enabled too. There are IPv4-only MSs, IPv4/IPv6 dual stack MSs and IPv6-olny MSs. Nam, et al. Expires April 18, 2006 [Page 7] Internet-Draft IPv6 over IEEE 802.16e October 2005 +----------------------------+ | BackBone | | Network | --- IPv4/IPv6 dual stack(enable) | +---+ +---+ | +-|ER |----------------|ER |-+ +---+ +---+ --- IPv4/IPv6 dual stack(enable) | | | | +-----+ +-----+ | BS | | BS | --- IPv4/IPv6 dual stack(enable) +-----+ +-----+ +--+ -- IPv6, IPv4/IPv6 dual stack, IPv4 |MN|-----> +--+ Figure 4. Phase 3 scenario 5. Considerations Some issues arise when implementing IPv6 over IEEE 802.16e. With the respect of ISPs, these can be devided into two main topics. 5.1 Mobility management aspect - Location management(location update) Identifying MS exact location is a key factor of location based services which will be one of the major service in the near future. Reducing control signals for location update are also important. Network Mobility (NEMO) and Hierarchical Mobile IPv6 protocol (HMIPv6) will be useful for location management. - Handover To support seamless connectivity, handover scheme is needed. Simple handover scheme will reduce handover overhead of network operation and maintenance (OAM) and those of MSs. Not only complexity but also latency of handover scheme should be considered. Handover latency is recommended within 150ms for real-time services such as VoIP and streamming media. Link extention for generic IP and/or MIPv4(MIPv6) can be considered for both IPv4 and IPv6 service as mobility Nam, et al. Expires April 18, 2006 [Page 8] Internet-Draft IPv6 over IEEE 802.16e October 2005 management schemes. In case of MIPv4(MIPv6), Fast Handovers will be useful. 5.2 Network aspect - Home agent location To support MSs mobility, Mobile IPv6 protocol can be considered as a mobility management protocol. Home Agent (HA) location has an influence on efficiency of mobility management, simplicity of servers management, distribution of traffic and routing optimazation and so on. The HA location is decided based on the anlysis of user mobility patterns during Phase 1. - IP allocation policy ISPs are reusing IP address with dynamic allocation because of lacking of IPv4 address space. With IPv6, this problem will be solved. ISPs do not need to worry about lack of IP address. ISPs focus on how efficient and simple to assign IP address to MSs and subnet. Static allocation, DHCP and auto-configuration are taken into account for IPv6 allocation. Service failure rate caused by user's IP address mis-configuration and server management cost will be decision factors of IP allocation policy. 6. Security considerations We do not consider any security issues in this draft. 7. References [1] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. [2] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004. [3] Lind, M., Ksinant, V., Park, S., Baudot, A., and P. Savola, "Mobility Support in IPv6", RFC 4029, March 2005. [4] Droms, Ed., R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [5] Thomson, S. and T. Narten, "IPv6 Stateless Address Autoconfiguration", RFC 2462, December 1998. Nam, et al. Expires April 18, 2006 [Page 9] Internet-Draft IPv6 over IEEE 802.16e October 2005 [6] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005. [7] Koodli, Ed., R., "Fast Handovers for Mobile IPv6", RFC 4068, July 2005. Authors' Addresses Minji Nam KT Portable Internet Team, Convergence Business Unit, KT 17 Woomyeon-dong, Seocho-gu Seoul 137-792 Korea Phone: +82-2-526-6121 Fax: +82-2-526-5200 Email: mjnam@kt.co.kr URI: http://mmlab.snu.ac.kr/~mjnam/ Eunkyoung Paik KT Portable Internet Team, Convergence Business Unit, KT 17 Woomyeon-dong, Seocho-gu Seoul 137-792 Korea Phone: +82-2-526-5233 Fax: +82-2-526-5200 Email: euna@kt.co.kr URI: http://mmlab.snu.ac.kr/~eun/ Sung Il Kim KT Portable Internet Team, Convergence Business Unit, KT 17 Woomyeon-dong, Seocho-gu Seoul 137-792 Korea Phone: +82-2-526-6118 Fax: +82-2-526-5200 Email: semperor@kt.co.kr Nam, et al. Expires April 18, 2006 [Page 10] Internet-Draft IPv6 over IEEE 802.16e October 2005 Se Jun Park KT Portable Internet Team, Convergence Business Unit, KT 17 Woomyeon-dong, Seocho-gu Seoul 137-792 Korea Phone: +82-2-526-6116 Fax: +82-2-526-5200 Email: sjpark@kt.co.kr Yu-seon Park KT Portable Internet Team, Convergence Business Unit, KT 17 Woomyeon-dong, Seocho-gu Seoul 137-792 Korea Phone: +82-2-526-6290 Fax: +82-2-526-5200 Email: yseonkim@kt.co.kr Nam, et al. Expires April 18, 2006 [Page 11] Internet-Draft IPv6 over IEEE 802.16e October 2005 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. 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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 (2005). 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. Nam, et al. Expires April 18, 2006 [Page 12]