INTERNET DRAFT Kent Leung Category: Individual submission Cisco Systems Title: draft-subbarao-mobileip-multipleip-00.txt Madhavi Subbarao Expires Septemer 2001 Cisco Systems Mobile IP Working Group Mobile IP NAI with Multiple Static IP Address Flows draft-subbarao-mobileip-multipleip-00.txt Status of this Memo This document is an Internet Draft and is in full compliance 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. Internet Drafts 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 A Network Access Identifier can be added to a Mobile IP Registration Request to identify a user. Users may want to open several simultaneous sessions using the same NAI from the same or different devices with a unique IP address for each session. The functionality defined in this draft can be used to allow multiple static IP address flows using the same NAI. 1. Introduction A Mobile IP Registration Request may carry a Network Access Identifier (NAI) [1,2] that serves to identify the user requesting access to the network. The NAI is used to also identify the necessary security assocation with the Home Agent (HA) or AAA server. With the abundance of mobile devices, a given user may want to open multiple, simultaneous Mobile IP sessions/services from the same or different devices. Currently, an NAI can only support a single Mobile IP flow. In this draft, we specify the functionality to allow for multiple static IP address flows using the same NAI. A mobility binding is then identified by the combination of NAI and MN home IP address. The functionality specified herein defines the behavior to support multiple static IP address flows using the same NAI in a wireless network deployment using Mobile IP, e.g., in a cdma2000 network [3]. 2. Mobile Node Considerations In order to support multiple IP address flows for an NAI, the Mobile Node (MN) and HA (or Home AAA server) MUST be preconfigured with valid static home IP addresses that the MN may use to register with the HA. The MN SHOULD send a Registration Request (RRQ) with its NAI and one of these valid static home IP addresses to the HA. Upon receipt of a Registration Reply (RPY), MN MUST use the home IP address returned by the HA for any subsequent RRQs pertaining to that session. If there is an error in the RPY, the MN MUST proceed as outlined in [4]. 3. Foreign Agent Considerations If an FA receives an RRQ from an MN with an NAI and an MN home address, the FA SHOULD index its pending registration records using the combination of NAI/MN home address. Upon receipt of an RPY from an HA, the FA SHOULD search its pending registration table based on NAI/MN home address pair. If it does not find an entry in this way, it SHOULD search the table based on the NAI and low-order 32 bits of the Identifier field in the RPY (this provides backward compatibility for dynamic address allocation using NAI and also if another authorized MN home address is returned by the HA). 4. Home Agent Considerations If an HA receives an RRQ with an NAI Extension and MN home address, the HA MUST first authenticate the RRQ as usual [1,3]. The HA MUST then check the validity of the MN home address against the preconfigured home IP addresses for the MN. The HA MAY authorize the MN home addresses against addresses configured via AAA or a local pool. If the MN home address included in the RRQ is not an authorized home address for the MN, the HA MUST reject the RRQ with error code 129 (administratively prohibited) as given in [4]. If the MN home address is authorized but already being used, and another valid home address for the MN is available, the HA MUST either return this address in its RPY or reject the RRQ with error code 130 (insufficient resources) as given by [4]. If another valid home address for the MN is not available, the HA MUST reject the RRQ with error code 130 (insufficient resources) as given by [4]. If an HA receives a re-registration from an MN, the HA MUST authorize the MN address as above and check that the MN address is the same address as in the existing mobility binding. 5. IANA Considerations This draft does not directly affect IANA. 6. Security Considerations Mobile IP registration messages are authenticated, and the authentication verified by the recipient. The static home addresses used by an MN are authorized by the HA as a valid home address for the MN. 7. IPv6 Considerations As with the NAI extension for Mobile IP [1], support for multiple static IP flows with NAI in IPv6 is outside the scope of this document. Any of the methods suggested there for creating an attendant function in the visited network could also make use of the functionality described in this draft to support multiple, static IP address flows/sessions. 8. Acknowledgements The authors would like to thank Roy Jose and Anand Sundaresh Natarajan for their insightful comments on the functionality specified in this draft. 9. References [1] P. Calhoun and C. Perkins, Mobile IP Network Access Identifier Extension for IPv4, RFC 2794, Internet Engineering Task Force, March 2000. [2] B. Aboba and M. Beadles, The Network Access Identifier. RFC 2486, Internet Engineering Task Force, January 1999. [3] TIA/EIA/IS-835, Wireless IP Network Standard, June 2000. [4] C. Perkins, IP Mobility Support for IPv4, revised, Internet Draft, Internet Engineering Task Force, draft-ietf-mobileip-rfc2002-bis-01.txt, Work in progress, January 2000. Author's Addresses Questions about this memo can be directed to: Kent Leung Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134 USA email: kleung@cisco.com phone: +1 408 526 5030 fax: +1 408 526 4952 Madhavi Subbarao Cisco Systems, Inc. 7025 Kit Creek Road Research Triangle Park, NC 27709 USA email: msubbara@cisco.com phone: +1 919 392 8387 Expires September 2001