Network Working Group J. Korhonen Internet-Draft U. Nilsson Expires: August 5, 2007 TeliaSonera February 2007 Service Selection for Mobile IPv4 draft-korhonen-mip4-service-01.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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 August 5, 2007. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract In some Mobile IPv4 deployments identifying the mobile node or the mobility service subscriber is not enough to distinguish between multiple services possibly provisioned to the said mobile node and its mobility service subscription. A capability to specify different services in addition to the mobile node identity can be leveraged to provide flexibility for mobility service providers to provide multiple services within a single mobility service subscription. This document describes a Service Selection Extension for Mobile IPv4 Korhonen & Nilsson Expires August 5, 2007 [Page 1] Internet-Draft Service Selection for MIPv4 February 2007 that is intended to assist home agents to make specific service selections for the mobility service subscription during the registration procedure. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Service Selection Extension . . . . . . . . . . . . . . . . . . 4 4. Processing Considerations . . . . . . . . . . . . . . . . . . . 5 4.1. Mobile Node Considerations . . . . . . . . . . . . . . . . 5 4.2. Home Agent Considerations . . . . . . . . . . . . . . . . . 5 4.3. Foreign Agent Considerations . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 8.1. Normative References . . . . . . . . . . . . . . . . . . . 7 8.2. Informative References . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 Intellectual Property and Copyright Statements . . . . . . . . . . 9 Korhonen & Nilsson Expires August 5, 2007 [Page 2] Internet-Draft Service Selection for MIPv4 February 2007 1. Introduction Mobile IPv4 [1] has a Network Access Identifier extension (MN-NAI) [6] that provides a flexible way to identify mobile nodes using other identifiers than IPv4 addresses. An example of such an identifier is the Network Access Identifier (NAI) [2]. In some Mobile IPv4 deployments, however, just identifying the mobile node or the mobility service subscriber via a proxy representative [7] is not enough to distinguish between multiple services possibly provisioned to the said mobile node and its mobility service subscription. The capability to specify different services in addition to the mobile node identity can be leveraged to provide flexibility for mobility service providers to provide multiple services within the same mobility service subscription. For example: o Provide an enterprise data access for which the mobility service provider hosts connectivity and mobility services on behalf of the enterprise. o Provide access to service domains that are otherwise not accessible from public networks because of some mobility service provider's business reasons. o Provide simultaneous access to different service domains that are separated based on policies of the mobility service provider. o Enable easier policy assignment for mobility service providers based on the subscribed services. o In absence of the Service Selection extension the home agent may provide, based on operator policies, a default service. For example, a plain Internet access could be an operator's default mobility service. This document describes a Service Selection Extension for Mobile IPv4 that is intended to assist home agents to make specific service selections for the mobility service subscription during the registration procedure. The service selection may affect home agent routing decisions and Home Address assignment policies. The Service Selection extension should be used in combination with the Mobile Node Identifier extension during the initial registration at the beginning of the mobility session. 2. Requirements The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", Korhonen & Nilsson Expires August 5, 2007 [Page 3] Internet-Draft Service Selection for MIPv4 February 2007 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [3]. 3. Service Selection Extension The Service Selection extension MAY be included in any Mobile IPv4 Registration Request message. The Service Selection extension MUST be placed in the Registration Request message as follows: o When present the extension MUST appear after the MN-NAI extension o If the extension was added by the mobile node to a Registration Request it MUST appear prior any authentication-enabling extensions [1][8] o In the event the foreign agent adds the Service Selection extension to a Registration Request, the extension MUST appear prior to any authentication-enabling extensions added by the foreign agent [1] This extension SHOULD be included only in the initial Registration Request message when registering to a home agent at the beginning of the mobility session. The MN-NAI extension SHOULD also be included in the Registration Request message when the Service Selection extension is used. However, sending the Service Selection extension in any Registration Request message is not prohibited. 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 = TBD | Length | Identifier... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Service Selection Extension o Type: 8-bit identifier set to TBD (to be defined by IANA) of the type of this skippable extension. o Length: 8-bit unsigned integer, representing the length of the Service Selection Identifier field. o Identifier: A variable length service identifier string used to identify the requested service. The Identifier string is encoded as a host name or a fully qualified domain name as defined in [4] and [5]. Korhonen & Nilsson Expires August 5, 2007 [Page 4] Internet-Draft Service Selection for MIPv4 February 2007 'deadcoderssociety' and 'deadcoderssociety.example.com' are valid examples of Service Selection extension Identifier strings. 4. Processing Considerations 4.1. Mobile Node Considerations A mobile node or its proxy representative MAY include the Service Selection extension into any Registration Request message. The extension is used to identify the service to be associated with the mobility session and SHOULD only be included into the initial Registration Request message sent to a home agent. The provisioning of the service identifiers to the mobile node or its proxy representative is out of scope of this specification. The Service Selection extension is intended to be used with the MN- NAI extension, but it is also possible to use Home Address to identify the mobile node as defined in [1]. 4.2. Home Agent Considerations Upon receiving the Service Selection extension the home agent authenticates and authorizes the mobile node. If the home agent supports the Service Selection it MUST also verify that the mobile node is authorized to the service identified by the Service Selection extension. The services the mobile node is authorized to SHOULD be part of the general mobile node subscription data. If the mobile node is not authorized to the service the home agent MUST deny the registration and send a Registration Reply with an error SERVICE_AUTHORIZATION_FAILED (error code TBD). The Service Selection extension is used to assist the mobile node authorization phase and identifies a specific service that is to be authorized. The Service Selection extension MAY also affect the Home Address allocation when for example used with the MN-NAI extension. For the same NAI there MAY be different Home Addresses depending on the identified service. Furthermore, the Service Selection extension MAY also affect the routing of the outbound IP packets in the home agent depending on the selected service. 4.3. Foreign Agent Considerations A foreign agent MUST ignore the Service Selection extension if the Registration Request already contains the Service Selection extension. If the Registration Request does not contain the Service Selection extension the foreign agent MAY add the Service Selection extension to the Registration Request message. How the foreign agent Korhonen & Nilsson Expires August 5, 2007 [Page 5] Internet-Draft Service Selection for MIPv4 February 2007 learns the service the mobile nodes needs to authorize is outside of scope of this document. 5. Security Considerations The protection for the Service Selection extension depends on the service that is being identified and eventually selected. If the service selection information should not be revealed on the wire it should be protected in a manner similar to Registration Requests and Registration Replies. The Service Selection extension is protected by the same authentication enabling extension as the rest of the Registration Request message. The home agent MUST verify that the mobile node is authorized to the service included in the Service Selection extension. The Service Selection extension authorization is part of the normal mobile node registration and authentication procedure. Both registration authentication and service authorization MUST succeed before the mobile node is allowed to register to the home agent. 6. IANA Considerations A new Mobile IPv4 skippable Extension type is required for the following new Extension described in Section 3. The Extension type must be from the 'skippable Extension' range (128-255): Service Selection Extension is set to TBD A new Mobile IPv4 registration denied by home agent error code is required. The error code must be allocated from the 'Error Codes from the Home Agent' range (128-192): SERVICE_AUTHORIZATION_FAILED is set to TBD 7. Acknowledgements The authors would like to thank Henrik Levkowetz and Kent Leung for their comments. 8. References Korhonen & Nilsson Expires August 5, 2007 [Page 6] Internet-Draft Service Selection for MIPv4 February 2007 8.1. Normative References [1] Perkins, C., "IP Mobility Support for IPv4", RFC 3344, August 2002. [2] Aboba, B., Beadles, M., Arkko, J., and P. Eronen, "The Network Access Identifier", RFC 4282, December 2005. [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [4] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [5] Faltstrom, P., Hoffman, P., and A. Costello, "Internationalizing Domain Names in Applications (IDNA)", RFC 3490, March 2003. 8.2. Informative References [6] Calhoun, P. and C. Perkins, "Mobile IP Network Access Identifier Extension for IPv4", RFC 2794, March 2000. [7] Leung, K., "Mobility Management using Proxy Mobile IPv4", draft-leung-mip4-proxy-mode-02 (work in progress), January 2007. [8] Perkins, C., Calhoun, P., and J. Bharatia, "Mobile IPv4 Challenge/Response Extensions (Revised)", RFC 4721, January 2007. Authors' Addresses Jouni Korhonen TeliaSonera Corporation. P.O.Box 970 FIN-00051 Sonera FINLAND Email: jouni.korhonen@teliasonera.com Korhonen & Nilsson Expires August 5, 2007 [Page 7] Internet-Draft Service Selection for MIPv4 February 2007 Ulf Nilsson TeliaSonera Corporation. Marbackagatan 11 S-123 86 Farsta SWEDEN Email: ulf.s.nilsson@teliasonera.com Korhonen & Nilsson Expires August 5, 2007 [Page 8] Internet-Draft Service Selection for MIPv4 February 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 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