INTERNET DRAFT JUNHYUK SONG January 2002 CHAE YOUNG CHONG SAMSUNG ELECTRONICS. DONGKIE LEE SK TELECOM DNS RR type for NAI draft-song-dnsext-nai-support-00.txt Status of This Memo Distribution of this memo is unlimited. 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." 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. Abstract This document proposes the use of the new DNS RR type "NAI" to specify the most current location of the user(Host IP address). Song and Lee. Expires July 2002 [Page 1] Internet Draft 4 January 2002 1. Introduction The demand for wireless mobile networking has been dramatically increased thanks to rapid development of wireless technology and de facto Mobile IP technology [1]. Therefore, the need for standardized method of specifying the user over different Internet Service Providers (ISPs) was identified. NAI is as defined in RFC-2486 provides the standardized method for identifying users in order to accomplish the interoperability for roaming and tunneling over multiple Internet Service Providers (ISPs). The NAI (Network Access Identifier) is of the form user@realm [3]. The DNS basically provides a mechanism to map between hostnames and IP address with support of many other RRs thorough hierarchically built domain names. Combining above two, NAI and DNS shall enable IP user mobility [2]. The IP user mobility is the ability of end user to send and receive IP datagrams regardless of the location of the mobile terminal and user location. This document specifies a new RR type for NAI, mapping host IP address and user identifier (NAI) [3]. 2. Applicability Statement The NAI RR defines user identifier, NAI widely used for PPP dialup connection and Mobile IPv4. The basic idea is to let mobile Internet user to constantly update its location(IP address), while moving around multiple access provider network. It can enables correspondent user to always reach the specific user by querying NAI to name server, regardless of the location. It is expected that NAI RR will be used in IRS(Internet Reachability Service) of 3GPP2 wireless IP network standard [4] (see Appendix A) and IP user mobility application [5]. Those application depends on one to one mapping of NAI and mobile host IP address in name server. Song and Lee. Expires July 2002 [Page 2] Internet Draft 4 January 2002 3. NAI RR Type NAI name space is resemble to Domain Name Space, except that it is a sequence of one or more labels, made of the user identifier and domain name. The "@" sign before realm, shall be treated as a delimiter to flag user ID part. Every user Identifier shall end with "@" sign and placed before domain name. NAI records cause no additional section processing The NAI record has the DNS RR type of "?", hence has the same QTYPE number of "?". Note NAI RR requires IANA number assignment. The class of NAI RR is defined in the IN class only. TTL should be configured to minimize the time of the RR being cached The RDATA of NAI is same as A RDATA format, 32 bit Internet Address 4. Examples Resource Record for NAI(junhyuk@samsung.skt.co.kr) is like below: junhyuk@.samsung.skt.co.kr. 86400 IN NAI 165.213.221.4 5. IANA Considerations It requires new RR type number from IANA. 6. Acknowledgements Special thanks to Prof. Murali Venkatesh of Syracuse University, and Dr. Woo June Kim Song and Lee. Expires July 2002 [Page 3] Internet Draft 4 January 2002 Appendix A. IRS of 3GPP2 wireless IP Network standard In this example, we've omitted the detail operation of deleting DNS record in case of user disconnect. In IRS, it is assumed that MS desires to be reached by a fixed identifier such as an NAI-like hostname 1. Simple IP operation Upon connecting to new access network MS(Mobile Station) shall generate CHAP authentication with NAI for user authentication. After successfully authenticate the user authentication request, AAAH shall send DNS A record update message to name server. (See figure 1) +--------------+ PPP CHAP (3) +--------------+ | | Auth Req | AAAH | | AAAF |-------------->| | | |<--------------| | +--------------+ PPP CHAP(5) +--------------+ ^ | Auth Ack | PPP CHAP | | User | Auth Req | | PPP CHAP Location | (2) | | Auth Ack Update(4)| | | (6) v | v +---------------+ +------+ PPP CHAP +-----------+ | Name Server | | | Auth Req (1) | | +---------------+ | |---------------------->| PDSN | ^ | |<----------------------| | User | | MS | PPP CHAP | | Location | | | Auth Ack (7) | | Query | | |<--------------------->| | | | | IP data (8) | | +-------+ +------+ | | <-----------| CH | +-----------+ IP data +-------+ Figure 1: Simple IPv4 operation Song and Lee. Expires July 2002 [Page 4] Internet Draft 4 January 2002 2. Mobile IP operation When the HA receives and successfully replies to an initial Mobile IP Registration Request, it performs the DNS update for the MS if it has previously received an indication from the home RADIUS server to do so, or has otherwise been provisioned to do so. The HA shall send a DNS Update message [RFC 2136] to the DNS server to add a Resource Record for the MS, if so required by the home RADIUS server [4]. (See figure 2) +--------------+ +--------------+ | |---------------->| | | AAAF | | AAAH | | |<----------------| | +--------------+ +--------------+ ^ | ^ Access | | Access | Request | v Accept v +------+ Agent +--------------+ +--------------+ | |Advertisement | | | | | | with FAC | PDSN/FA | | Mobile IPv4 | | MS |<------------ | | | Home Agent | | |------------> | |---------------->| | | |Mobile IP RRQ | |Mobile IP RRQ | | | |with MN-AAA | | | | | |<-------------| |<----------------| | +------+Mobile IP RRP +--------------+Mobile IP RRP +--------------+ | User | Location | Update | v +--------------+ | Name Server | +--------------+ Figure 2: Mobile IPv4 operation Song and Lee. Expires July 2002 [Page 5] Internet Draft 4 January 2002 References [1] C. Perkins, Editor. "IP Mobility Support". RFC 2002. October 1996. [2] J.H Song, C.Y Chong, DK Lee "draft-song-network-user-mobility-00.txt [3] Bernard Aboba and Mark A. Beadles "The Network Access Identifier". RFC 2486. January 1999. [4] 3GPP2 P.S0001-B work in progress. [5] J.H Song and C.Y Chong, DK Lee "draft-song-mobileip-mipv6-user-mobility-00.txt" Addresses Questions about this memo can be directed to the authors: JUNHYUK SONG CHAEYOUNG CHONG SAMSUNG ELECTRONICS. Mobile Development Team Network Systems Division Phone: +82-31-279-3639 Email: santajun@lycos.co.kr DONGKIE LEE SK TELECOM Core Network Development Team Network R&D Center Phone +82-2-829-4640 Email: galahad@netsgo.com FAX:+82-2-829-4612 Song and Lee Expires July 2002 [Page 6]