Internet Draft SH.Kwon Intended status: Experimental SJ.Koh Expires: February 2010 Kyoung-pook National University August 25, 2009 QMIP: Query-based Mobile IP draft-kwon-qmipv4-00.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/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 February 25, 2009. 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 Mobile IP (MIP) suffers from the so-called triangular routing problem. Moreover, MIP Home Agent (HA) tends to undergo severe data traffic load, since it should deliver all the data packets toward mobile nodes. This paper proposes a simple extension of MIP, called Query- Kwon, Koh Expires February 25, 2010 [Page 1] Internet-Draft QMIP: Query-based Mobile IP August 2009 based MIP (QMIP), in which the binding query to HA will be used to get the care-of address of a mobile node and to deliver the subsequent data packets over the optimized data path. The proposed QMIP scheme can be applied to MIPv4 and Proxy MIPv6 as well. Table of Contents 1. Introduction ................................................ 2 2. Conventions used in this document ............................ 3 3. Query-Based MIPv4 ........................................... 3 3.1. Data Transmission with Binding Query .................... 3 3.2. Comparison with MIPv4 ................................... 4 3.3. New Message for QMIPv4 .................................. 6 3.4. Consider of Query-Based Proxy MIPv6 ..................... 7 4. Security Considerations ...................................... 8 5. IANA Considerations ......................................... 8 6. Conclusions ................................................. 8 7. References .................................................. 8 7.1. Normative References .................................... 8 7.2. Informative References .................................. 8 8. Acknowledgments ............................................. 8 1. Introduction The Mobile IP (MIP) was designed to support IP mobility [2]. However, it suffers from the well-known 'triangular routing' problem, in which Correspondent Node (CN) should transmit data packets to Mobile Node (MN) via Home Agent (HA) over a non-optimized data path, until the route optimization is additionally performed between CN and MN. Another crucial concern of MIP is the excessive data traffic load at HA, since all the data packets from CNs toward MNs should be delivered by way of HA. Such overhead at HA will become much severe, as the number of MNs increases in the network. This paper proposes a simple extension of MIPv4, called Query-based MIPv4 (QMIPv4), in which the Access Router (AR) attached to CN will perform the binding query to HA, so as to get the Care-of Address (CoA) of MN and to deliver all the subsequent data packets over the optimized data path. For this purpose, we define the two new messages: Binding Query Request and Binding Query Reply. The proposed QMIP scheme can also be applied to the Proxy MIPv6 (PMIPv6) [3], rather than MIPv6 [4], since PMIPv6 has the similar structure with MIPv4. We will first present QMIPv4, and then discuss Query-based PMIPv6. Kwon, Koh Expires February 25, 2010 [Page 2] Internet-Draft QMIP: Query-based Mobile IP August 2009 2. Conventions used in this document In examples, "C:" and "S:" indicate lines sent by the client and server respectively. 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 RFC-2119 [1]. 3. Query-Based MIPv4 3.1. Data Transmission with Binding Query We consider a simple network model for QMIPv4, as depicted in Fig. 1. In the figure, MN performs the MIPv4 registration (or binding update), and then CN tries to communicate with MN. The AR attached to CN acts as a normal router with its own Query Cache (QC) table. This QC table will be referred to by AR to identify the CoA of MN. Note that this AR may also function as a Foreign Agent (FA) in the network. Now, CN transmits data packets to MN over Home Address (HoA) of MN. On reception of the first data packet destined to MN, the AR will first look for CoA of MN in its QC table. If the corresponding CoA is found in the table (we call it Cache Hit), AR will deliver the data packet directly to MN by using the IP-in-IP tunneling. Otherwise, if the CoA is not found (we call it Cache Miss), the AR will send a Binding Query Request message to HA so as to get the CoA. Then, HA responds with a Binding Query Reply message (containing CoA of MN) to AR. The resulting information of mapping between HoA and CoA of MN will be recorded into the QC table of AR, which will be referred to by AR in the subsequent data transmissions to MN. Kwon, Koh Expires February 25, 2010 [Page 3] Internet-Draft QMIP: Query-based Mobile IP August 2009 +--+ |HA| +--+ // \\ Binding Query // \\Binding Update // \\ // \\ +--+ +--+ +--+ +--+ |CN| <=====> |AR| <====> |FA| <=====> |MN| +--+ +--+ +--+ +--+ +-----+ |Query| |Cache| +-----+ AR: Access Router // Control Signal FA: Foreign Agent <=> User Data Transport CN: Correspondent Node MN: Mobile Node Figure 1 Network model for QMIPv4 3.2. Comparison with MIPv4 Fig. 2 compares the information flows of MIPv4 and QMIPv4. Kwon, Koh Expires February 25, 2010 [Page 4] Internet-Draft QMIP: Query-based Mobile IP August 2009 +--+ +--+ +--+ +--+ +--+ |CN| |AR| |HA| |FA| |MN| +--+ +--+ +--+ +--+ +--+ | | | MIP Binding Update | | | | <-------> | <-------> | | |Initial Data Transport | | |=========> |=========> |=========> |=========> | | | | | | |<========= |<===================== |<========= | | | | | | | | . | . | | | | . | . | | | | | | | | |MIP Route Optimization | | | |<--------------------> | | | | | | | | | Data Transport after | | | | Route Optimization | | |<========> |<====================> |<========> | | | | | | (a)MIPv4 +--+ +--+ +--+ +--+ +--+ |CN| |AR| |HA| |FA| |MN| +--+ +--+ +--+ +--+ +--+ | | | MIP Binding Update | | | | <-------> | <-------> | |Cache Miss |QMIP Bind- | | | | \|ing Query | | | |=========> |<--------> | | | | | Data Transport | | | |=====================> |=========> | | Cache Hit | | | | | \| | | | |<========> |<====================> |<========> | | | | | | (b)QMIPv4 Figure 2 Information flows of MIPv4 and QMIPv4 In MIPv4, MN will perform the registration with HA. All the data packets transmitted by CN will be forwarded to HA and delivered by HA to MN using the IP-in-IP tunneling, whereas MN will transmit its data packets directly to CN, and hence the triangular routing occurs. Just Kwon, Koh Expires February 25, 2010 [Page 5] Internet-Draft QMIP: Query-based Mobile IP August 2009 after the route optimization, CN can use the optimized path for data delivery to MN. The QMIPv4 is the same with MIPv4, other than the binding query operation with HA. When the first data packet arrives from CN, AR will search for the corresponding CoA of MN in its QC table. In case of Cache Hit that the CoA is found in the table, AR can transmit the data packet directly to MN over the optimized path. However, in case of Cache Miss, AR should perform the binding query to HA. After this, all the subsequent data packets will be delivered to MN over the optimized route, without further binding query operations. Note that in MIPv4 the data transport between MN and CN will be done over the optimized route, just after the route optimization is completed, whereas the proposed QMIPv4 can intrinsically realize the route optimization with a single binding query operation. Moreover, in QMIPv4, Cache Hit may occur even for the first data packet of CN (i.e., the binding query operation can be omitted), if another CN in the same AR region is already communicating with the identical MN at that time. With the data transport over the optimized path, QMIPv4 can reduce the transmission delays of data packets, compared to MIPv4. In addition, QMIPv4 can avoid the problem of the excessive data traffic load at HA, since the data transmission to MN will be performed by the concerned AR, instead of HA, in the distributed manner. 3.3. New Message for QMIPv4 To support the QMIPv4, the two messages need to be newly defined: Binding Query Request (from AR to HA) and Binding Query Reply (from HA to AR). These messages can be defined in the similar format with the MIP registration request/reply messages, as shown in Fig. 3. Kwon, Koh Expires February 25, 2010 [Page 6] Internet-Draft QMIP: Query-based Mobile IP August 2009 +----------+----------+-------------------+ | Type | Code | Lifetime | +-----------------------------------------+ | Home Address | +-----------------------------------------+ | Home Agent | +-----------------------------------------+ | | | Identification | | | +-----------------------------------------+ | Extensions | +-----------------------------------------+ (a)Binding Query Request +----------+----------+-------------------+ | Type | Code | Lifetime | +-----------------------------------------+ | Home Address | +-----------------------------------------+ | Home Agent | +-----------------------------------------+ | Care-of Address | +-----------------------------------------+ | | | Identification | | | +-----------------------------------------+ | Extensions | +-----------------------------------------+ (b)Binding Query Reply Figure 3 Add a caption as here. As shown in the figure, the Binding Query Request message contains the information on HA and HoA of MN, whereas the Binding Query Reply message additionally includes CoA of MN. The specific types of messages are for further study. 3.4. Consider of Query-Based Proxy MIPv6 The Query-based MIP scheme can also be applied to the Proxy MIPv6. In this case, the PMIPv6 Mobile Access Gateway will function as the QMIPv4 AR and/or FA, and the PMIPv6 Localized Mobility Agent acts as the QMIPv4 HA. In addition, the PMIPv6 Proxy Binding Update messages Kwon, Koh Expires February 25, 2010 [Page 7] Internet-Draft QMIP: Query-based Mobile IP August 2009 may need to be extended to support the binding query operation. Details of the Query-based PMIPv6 are for further study. 4. Security Considerations To be continue. 5. IANA Considerations This specification has no actions for IANA. 6. Conclusions This paper presents the Query-based MIP scheme that uses the binding query to HA so as to get the optimized data path. The proposed QMIP scheme can be applied to both MIPv4 and PMIPv6. In QMIP, we can achieve much smaller transmission delay of data packets than MIP in the usual case. Moreover, the QMIP is helpful to avoid the excessive data traffic load at HA, since the data transmission to MN will be performed by AR in the network, instead of HA. 7. References 7.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 7.2. Informative References [2] IETF RFC 3344, IP Mobility Support for IPv4, August 2002 [3] IETF RFC 5213, Proxy Mobile IPv6, August 2008 [4] IETF RFC 3775, Mobility Support in IPv6, June 2004 [5] IETF RFC 4988, Mobile IPv4 Fast Handovers, October 2007. 8. Acknowledgments Thanks goes to Hee Young Jung who have made insightful comments with respect to interworking and careful review. This document was prepared using 2-Word-v2.0.template.dot. Kwon, Koh Expires February 25, 2010 [Page 8] Internet-Draft QMIP: Query-based Mobile IP August 2009 Authors' Addresses Soon Hong Kwon Kyoung-pook National University Email: K.soonhong@gmail.com Seok Joo Koh Kyoung-pook National University Email: sjkoh@knu.ac.kr Kwon, Koh Expires February 25, 2010 [Page 9]