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]