Internet Engineering Task Force Yunyong Zhang IPv6 Working Group Yunjie Liu INTERNET-DRAFT Zhijiang Zhang Expires: October 1, 2004 China United Telecommunications Corporation April 1, 2004 Add anycast in mobile ipv6 router message draft-zhangyy-ipv6-mobile-router-anycast-routing-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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." To view the list Internet-Draft Shadow Directories, see http://www.ietf.org/shadow.html. Distribution of this memo is unlimited. The internet-draft will expire in 6 months. The date of expiration will be July 1, 2004. Abstract The memo tries to add anycast mechanism in current ICMP router solicitation message and router advertisement message so as to use one compound message to get both care-of address and unicast address of server. Table of Contents 1. Introduction................................................2 2. Terminology.................................................2 3. New Message.................................................3 3.1 Compound Request Message...................................3 3.2 Compound Reply Message.....................................4 4. Description of Process......................................6 4.1. Mobile Node Process.......................................6 4.1.1 Sending Compound Request Process.........................6 4.1.2 Receving Compound Reply Process..........................6 4.2. Router Process............................................6 ZHANG, LIUú¼ZHANG Expires: October 1, 2004 [Page 1] INTERNET-DRAFT draft-zhangyy-ipv6-mobile-anycast-00.txt Apr 2004 5. Analysis ...................................................7 6. Acknowledgments.............................................7 7. References..................................................7 8. Authors' addresses..........................................7 9. Intellectual Property Rights Notice.........................8 10. Full Copyright Statement...................................8 1. Introduction Currently, four sequences are included strictly from mobile nodes arriving at foreign network to finishing connections with anycast server, shown in figure 1. Mobile Node Router Server + + + | (1) | | | ========í¸ | | | | | | (2) | | | íµ======== | | | | | | (3) | | ==========================í¸| | | | | (4) | | íµ========================= | | | | + + + Figure 1 Sequences of getting CoA and anycast server's address (1) Mobile node in foreign network sends ICMP router solicitation message to router; (2) Router sends CoA address in ICMP router advertisement message to MN; (3) Mobile node which owned CoA sends ICMP ECHO request message to the anycast address; (4) Server sends unicast address of server in ICMP ECHO message to mobile node. Sequence (1) and (2) are introduced in [Johnsonú¼2003]ú¼and sequence (3) and (4) are introduced in [Haginoú¼ 2003]. In fact sequence (1) and (3) can be combined, also sequence (2) and (4) can be combined together. In this draft, compound request and compound reply message are defined according legacy router solicitation message and router advertisement message to improve the efficiency and reduce network overload. ZHANG, LIUú¼ZHANG Expires: October 1, 2004 [Page 2] INTERNET-DRAFT draft-zhangyy-ipv6-mobile-anycast-00.txt Apr 2004 2. Terminology 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 [Bradner, 1997]. Compound Request( C_Rq) Router solicitation message containing anycast address and option. Compound Reply(C_Rp) Router advertisement message containing anycast address, unicast address and option. 3. New Message In this draft, two messages are introduced. One is compound request (figure 2) and the other is compound reply messge(figure 3). 3.1. Compound Request Message 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved |A| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Anycast address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2 Anycast Routing Table Update Request Message format ICMPv6 Fields: Type type of ICMP message. Code depends on the message type. Checksum is used to detect data corruption in the ICMPv6 message and parts of the IPv6 header. Reserved unsed field. It MUST be initialized to zero. A one anycast bit, initialized to 1 to indicate that the following is 128 bits anycast address(With RFC 2373, anycast address can not be distinguishable from unicast address). Anycast address address of anycast router. ZHANG, LIUú¼ZHANG Expires: October 1, 2004 [Page 3] INTERNET-DRAFT draft-zhangyy-ipv6-mobile-anycast-00.txt Apr 2004 Options some options. 3.2. Compound Reply Message 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Cur Hop Limit |M|O|H|A| Res | Router Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reachable Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Retrans Timer | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Anycast address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Unicast address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3 Anycast Routing Table Update Advertisement Message format ICMPv6 Fields: Type type of ICMP message and is allocated by IANA. Code depends on the message type. It is used to create an additional level of message granularity, and is set to zero. Checksum is used to detect data corruption in the ICMPv6 message and parts of the IPv6 header. Cur Hop 8-bit unsigned integer. The default value that should be placed in the Hop Count field of the IP header for outgoing IP packets. A value of zero means unspecified. M 1-bit Managed Address Configuration flag. When set, hosts use the administered (stateful) protocol for address autoconfiguration in addition to any addresses autoconfigured using stateless address autoconfiguration. O 1-bit Other Stateful Configuration flag. When set, hosts use the administered (stateful) protocol for autoconfiguration of other(non-address) information. H The Home Agent (H) bit is set in a Router Advertisement to indicate that the router sending this Router Advertisement is also functioning as a Mobile IPv6 home agent on this link. ZHANG, LIUú¼ZHANG Expires: October 1, 2004 [Page 4] INTERNET-DRAFT draft-zhangyy-ipv6-mobile-anycast-00.txt Apr 2004 A one anycast bit, initialized to 1 to indicate that the following is 128 bits anycast address(With RFC 2373, anycast address can not be distinguishable from unicast address). Reserved unsed field. It MUST be initialized to zero. Router lifetime 16-bit unsigned integer. The lifetime associated with the default router in units of seconds. The maximum value corresponds to 18.2 hours. A Lifetime of 0 indicates that the router is not a default router and SHOULD NOT appear on the default router list. The Router Lifetime applies only to the router's usefulness as a default router; it does not apply to information contained in other message fields or options. Options that need time limits for their information include their own lifetime fields. Reachable time 32-bit unsigned integer. The time, in milliseconds, that a node assumes a neighbor is reachable after having received a reachability confirmation. A value of zero means unspecified. Retrans timer 32-bit unsigned integer. The time, in milliseconds, between retransmitted Neighbor Solicitation messages. A value of zero means unspecified . Anycast address anycast of anycast router. Unicast address unicast address item in anycast routing table. Options some options. 4. Description of Process Communication processes of sending compound request message and receiving compound message are shown in figure 4. Mobile Node Router + + | 4.1 | | ========í¸ | | | | | | | | 4.2 | | íµ======== | | | + + Figure 4 communication process of compound message ZHANG, LIUú¼ZHANG Expires: October 1, 2004 [Page 5] INTERNET-DRAFT draft-zhangyy-ipv6-mobile-anycast-00.txt Apr 2004 4.1. Mobile Node Process 4.1.1 Sending Compound Request Process Algorithm: Sending C_Rq message-MN If a MN needs anycast service Then Let anycast address field of C_Rq message be the anycast address corresponding to the anycast service Let A field of C_Rq message to be 1 Let source address field of C_Rq message be IP address of the interface that sending messge Let Destination address field of C_Rq message to be FF02::2 Else undo 4.1.2 Receiving Compound Reply Process Algorithm:Receiving C_Rp message-MN If router lifetime field of C_Rp message is not equal to zero If options field's address prefix=prefix of destination address Then forms the MN's CoA Else undo If A field=1 If anycast address in the anycast address field is MN wanted Then let unicast address field be the anycast server's unicast address Else undo 4.2 Router Process Algorithm:Router If Router can be the MN's default router Let router lifetime field of C_Rp message not to be zero Else let router lifetime field of C_Rp message =0 If Router supports the anycast service MN needed Then Let anycast address field of C_Rp message be anycast address correesponding to the anycast service Let unicast address field of C_Rp message be anycast server's unicast address Let A field of C_Rp message be 1 Else If router lifetime field of C_Rp not equal to zero Let A field of C_Rp message be 0 Let anycast address field of C_Rp message to 0:0:0:0:0:0:0:0 Let unicast address field of C_Rp message to 0:0:0:0:0:0:0:0 Else forwards request message to other router and exit Let source address field of C_Rp message be IP address of the interface that sending message Let destination address field of C_Rp message be source address field of the corresponding C_Rq message ZHANG, LIUú¼ZHANG Expires: October 1, 2004 [Page 6] INTERNET-DRAFT draft-zhangyy-ipv6-mobile-anycast-00.txt Apr 2004 5. Analysis Add anycast in mobile ipv6 router message has following advantages; Responding time of COA address and serverí¯s address is reduced. Overload of server is also reduced due to connections of communication are reduced. Performance of network transportation is increased. Congestion is partly avoided and usage of network resource is also increased. The new anycast routing protocol is transparent to other mobile ip entity such as home agent and corresponding node. 6. Acknowledgments The authors would like to thank professor Jinde Liu and for his careful review. 7. References Bradner, 1997 S. Bradner, í—Key words for use in RFCs to Indicate Requirement Levelsí˜ in RFC (Best Current Practice) 2119(March 1997). ftp://ftp.isi.edu/in-notes/rfc2119.txt. Hinden, 1998. R. Hinden and S. Deering, "IP Version 6 Addressing Architecture" in RFC2373 (July 1998). http://www.ietf.org/rfc/rfc2373.txt. Haginoú¼ 2003. Jun-ichiro itojun Hagino, " An analysis of IPv6 anycast " in draft-ietf-ipngwg-ipv6-anycast-analysis-02.txt (June 2003). work in progress material. Nartenú¼ 1998. Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. Johnsonú¼2003 Johnson, D., Perkins, C., Arkko J., "Mobility Support in IPv6" in í—draft-ietf-mobileip-ipv6-24.txtí˜ú¿June 30, 2003ú¨.work in progress material. 8. Authors' addresses Yunyong Zhang Department of Technologyú¼ China United Telecommunications Corporationú¼ No.133A, Xidan North Street,Xichen Districtú¼ Beijingú¼100032ú¼China P. R ZHANG, LIUú¼ZHANG Expires: October 1, 2004 [Page 7] INTERNET-DRAFT draft-zhangyy-ipv6-mobile-anycast-00.txt Apr 2004 Tel: +86-10-6650-5740 Fax: +86-10-6650-4252 E-mail: zhangyy@chinaunicom.com.cn Yunjie Liu China United Telecommunications Corporationú¼ No.133A, Xidan North Street,Xichen Districtú¼ Beijingú¼100032ú¼China P. R Tel: +86-10-6650-5115 Fax: +86-10-6650-4252 E-mail: liuyj@chinaunicom.com.cn Zhijiang Zhang Department of Technologyú¼ China United Telecommunications Corporationú¼ No.133A, Xidan North Street,Xichen Districtú¼ Beijingú¼100032ú¼China P. R Tel: +86-10-6650-5120 Fax: +86-10-6650-4252 E-mail: zhangzhj@chinaunicom.com.cn 9. Intellectual Property Rights Notice The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication 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 implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. 10. Full Copyright Statement Copyright (C) The Internet Society (2004). All Rights Reserved. ZHANG, LIUú¼ZHANG Expires: October 1, 2004 [Page 8] INTERNET-DRAFT draft-zhangyy-ipv6-mobile-anycast-00.txt Apr 2004 This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. 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