Network Working Group P. Kim Internet-Draft Korea Polytechnic University Expires: Aug 24, 2006 Feb 24, 2006 Link Specified CoA Configuration for Heterogeneous Access Networks draft-pskim-link-specified-coa-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 August 22, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This specification defines newly the care-of addresss configuration specified by the new link of the mobile node for Mobile IPv6 handovers in heterogeneous access networks, which allows the correspondent node to know the new link of the mobile node. Using the link specified care-of address, the correspondent node can adjust quickly real-time traffics according to the available bandwidth to the mobile node. Kim Link Specified CoA Configuration [Page 1] Internet-Draft Link Specified CoA Configuration Feb 2006 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Forming Care-of Addresse Specified by New Link Type. . . . . . 4 3.1 New EUI-64 Format for Care-of Address. . . . . . . . . . . . 4 3.2 Adusting Real-time Traffics using Link Specified CoA . . . . 4 4. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 7 Intellectual Property and Copyright Statements . . . . . . . . 8 Kim Link Specified CoA Configuration [Page 2] Internet-Draft Link Specified CoA Configuration Feb 2006 1. Introduction Recently, many works have been proposed to support seamless mobility in future IPv6 based access networks [1]-[3]. One of the challenges in keeping connection with the Internet, as a mobile node moves, is to communicate efficiently on the move and to minimize to packet loss caused by a vertical handover in heterogeneous access network environment where more and more mobile nodes equipped with multiple interfaces for different L2 techonologies may reachable through different links at the same time or use each interface alternately depending on the network environment. In recent, to indicate the new link of the mobile node for vertical handovers in heterogeneous access networks environment, the draft [4] was introduced a new model for link characteristic information delivery from the mobile node to the correspondent node for Mobile IPv6. The ultimate purpose of this model was to let the correspondent node properly adjust its real-time traffics to the mobile node according to the new link of the mobile node. In this dratf, for vertical handovers in heterogeneous access networks environment, an alternative approach is suggested to allow the correspondent node to know the new link of the mobile node for Mobile IPv6. This draft gives a new method for mobile node to create a care-of address (CoA) which is specified by the new link. In this method, an EUI-64 identifier for the CoA configuration is made from an IEEE 48bit MAC identifier using the link type value. Then, the correspondent node can know the new link of the mobile node from the return routablility procedure including link specified CoA, whereas the previous approach in [4] can know it from the binding update procedure with additive mobility option. As proposed in [4], the correspondent node in the propsed approach can also adjust real-time traffics according to the newl link's available bandwidth to the mobile node using this link specified CoA. It is remarkable that the proposed approach can prepare more quickly to adjust real-time traffics than the previous approach in [4], since the return routability procedure precedes the binding update procedure. 2. Requirements 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]. Kim Link Specified CoA Configuration [Page 3] Internet-Draft Link Specified CoA Configuration Feb 2006 3. Forming Care-of Addresse Specified by New Link Type According to the Mobile IPv6 specification, a mobile node should generate a new primary care-of address (CoA) using normal IPv6 mechanisms, after detecting that it has moved to a foreign link. A mobile node can have only one primary CoA at a time (which is registered with its home agent), but it may have an additional CoA for any or all of the prefixes on its new link. Furthermore, since a wireless network interface may actually allow a mobile node to be reachable on more than one link at a time (i.e., within wireless transmitter range of routers on more than one separate link), a mobile node may have CoAs on more than one link at a time. In order to form a new CoA, a mobile node may use either stateless [5] or stateful (e.g., DHCPv6 [6]) address autoconfiguration. In case of the stateless address autoconfiguration, a mobile node can generate its CoAs using a combination of locally available information and information advertised by routers in foreign links. Routers advertise prefixes that identify the subnet(s) associated with a foreign link, while mobile nodes generate an "interface identifier" that uniquely identifies an interface on a subnet. An address is formed by combining the two. Generally, the CoA using stateless autoconfiguration has the following form: +---------------------------------+--------------------------------+ | subnet prefix for foreign link |interface ID (EUI-64 identifier)| +---------------------------------+--------------------------------+ 3.1 New EUI-64 Format for Care-of Address To indicate the currently active link of the mobile node for vertical handovers in heterogeneous access networks environment, this draft gives a new method to create a CoA which is specified by the new link. In this method. a EUI-64 identifier is made from an IEEE 48bit MAC identifier using the link type value as shown in Table 1. As shown in [7], in order to make 64 bits EUI-64 from 48 bits MAC, two hexadecimal values of 0xFF and 0xFE is added in the middle of the 48 bit MAC (between the company_id and vendor supplied id). To create link specified CoA, the second hexadcimal value "0xFE" will be replaced by the link type value defined as follows. Table.1 Link Type Values -------------------------------------------------------- link type value IEEE link type -------------------------------------------------------- 0xFD 802.11b (WLAN) 0xFC 802.11a (WLAN) 0xFB 802.11g (WLAN) 0xFA 802.11n (WLAN) 0xE0 802.3 (LAN) 0xD0-DF IEEE 802.16 Family Networks 0xC0-CF IEEE 802.15 Family Networks 0xB0-BF Reserved for IEEE 802 Extensions -------------------------------------------------------- Kim Link Specified CoA Configuration [Page 4] Internet-Draft Link Specified CoA Configuration Feb 2006 For example, IEEE 802.11b WLAN has the 48 bit MAC as follow: |0 1|1 3|3 4| |0 5|6 1|2 7| +----------------+----------------+----------------+ |cccccc0gcccccccc|ccccccccmmmmmmmm|mmmmmmmmmmmmmmmm| +----------------+----------------+----------------+ where "c" are the bits of the assigned company_id, "0" is the value of the universal/local bit to indicate global scope, "g" is individual/group bit, and "m" are the bits of the manufacturer- selected extension identifier. The link type value of IEEE 802.11b WLAN is "0xFD", then the interface identifier with 64 bits EUI-64 for the link specified CoA is of the following form: |0 1|1 3|3 4|4 6| |0 5|6 1|2 7|8 3| +----------------+----------------+----------------+----------------+ |cccccc1gcccccccc|cccccccc11111111|11111101mmmmmmmm|mmmmmmmmmmmmmmmm| +----------------+----------------+----------------+----------------+ As another example, the link type value of IEEE 802.16e WLAN is assumed to be "0xD0", then the interface identifier with 64 bits EUI-64 for the link specified CoA is of the following form: |0 1|1 3|3 4|4 6| |0 5|6 1|2 7|8 3| +----------------+----------------+----------------+----------------+ |cccccc1gcccccccc|cccccccc11111111|11010000mmmmmmmm|mmmmmmmmmmmmmmmm| +----------------+----------------+----------------+----------------+ 3.2 Adusting Real-time Traffics using Link Specified CoA It is shown that the correspondent node can adjust real-time traffics according to the new link's available bandwidth to the mobile node using the link specified CoA, when the mobile node is on the vertical handover in heterogeneous access networks environment. Assume that the mobile node communicates with the corresponding node using available bandwidth for the current link. In real-time communication, when the mobile node moves to the new link, it creates a link specified CoA using the new link's interface identifier. Then, the mobile node performs the binding procedure with its's home agent to register its link specified CoA. Then, for the binding procedure between the mobile node and the correspondent node, the return routability procedure is performed to enable the correspondent node to obtain some reasonable assurance that the mobile node is in fact addressable at its claimed link specified CoA as well as at its home address. Only with this assurance is the correspondent node able to accept binding update from the mobile node which would then instruct the correspondent node to direct that mobile node's data traffic to its claimed link specified CoA. For the return routablility, the Home Test Init (HoTI) and Care-of Test Init (CoTI) messages are sent at the same time. Kim Link Specified CoA Configuration [Page 5] Internet-Draft Link Specified CoA Configuration Feb 2006 The procedure requires very little processing at the correspondent node, and the Home Test (HoT) and Care-of Test (CoT) messages can be returned quickly, perhaps nearly simultaneously. As shown in Figure 1, the CoTI message uses the link specified CoA as the source address and the CoT messgage uses the link specified CoA as the destination address. Thus, the correspondent node can recognize the new link of the mobile node from CoTI message and can prepare to adjust real-time traffics with the mobile node using available bandwith of the new link. After authorized binding procedure with the mobile node, the correspondent node can adjust real-time traffic amount or pattern sent to the mobile node according to the new link's available bandwidth. As mentioned in [4], the specific traffic control method is also out of the scope of this document. As mentioned before, the correspondent node can know the new link of the mobile node from the return routablility procedure including link specified CoA, whereas the previous approach in [4] can know it from the binding update procedure with additive mobility option. Therefore, the proposed approach can prepare more quickly to adjust real-time traffics than the previous approach in [4], since the return routability procedure precedes the binding update procedure. Mobile node Home agent Correspondent node | | currently attach to 802.11b link | | adjusting traffics with 802.11b bandwidth | | | Real-time traffics | |<=================================================>| | | newly attach to 802.16e link | | | forming 802.16e link specified CoA | | | | Binding Procedure | | |<---------------------->| | | HoTI | | |----------------------->|------------------------->| | CoTI with Link Specified CoA | |-------------------------------------------------->| | | HoT | |<-----------------------|<-------------------------| | CoT with Link Specified CoA | |<--------------------------------------------------| | prepare adjusting traffics 802.16e bandwidth | | | Authorized Binding Procedure | |<------------------------------------------------->| | | | adjusting traffics with 802.16e bandwidth | Real-time traffics | |<=================================================>| Figure 1. Adusting Real-time Traffics using Link Specified CoA Kim Link Specified CoA Configuration [Page 6] Internet-Draft Link Specified CoA Configuration Feb 2006 4. References [1] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004. [2] McCann, P. "Mobile IPv6 Fast Handovers for 802.11 Networks", IETF Draft:draftietf-mipshop-80211fh-04.txt, Feb 2005. [3] Koodli, R. "Fast Handovers for Mobile IPv6", IETF RFC 4068, Jul 2005. [4] Park, S., Lee, M., Korhonen, J., and J. Zhang, "Link Characteristics Information for Mobile IP", IETF Draft:draft-daniel-mip-link-characteristic-02.txt, June 8, 2005 [5] Thomson, S. and T. Narten, "IPv6 Stateless Address Autoconfiguration", RFC 2462, December 1998. [6] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, C. and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [7] Hinden, R., and S. Deering "Internet Protocol Version 6 (IPv6) Addressing Architecture", RFC 3513, April 2003. Authors' Addresses Pyungsoo Kim Department of Electronics Engineering, Korea Polytechnic University, 2121 Jungwang-Dong, Shiheung City, Gyeonggi-Do 429-793 KOREA Phone: +82 31 496 8413 EMail: pskim@kpu.ac.kr Kim Link Specified CoA Configuration [Page 7] Internet-Draft Link Specified CoA Configuration Feb 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. 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