Diameter Maintenance and J. Korhonen (ed.) Extensions (DIME) TeliaSonera Internet-Draft J. Bournelle Intended status: Informational GET/INT Expires: December 3, 2006 H. Tschofenig Siemens C. Perkins Nokia K. Chowdhury Starent Networks June 2006 The NAS - HAAA Interface for MIPv6 Bootstrapping draft-ietf-dime-mip6-integrated-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 December 3, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract A Mobile IPv6 node requires a home agent address, a home address, and Korhonen (ed.), et al. Expires December 3, 2006 [Page 1] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 IPsec security association with its home agent before it can start utilizing Mobile IPv6 service. RFC 3775 requires that some or all of these parameters are statically configured. Ongoing Mobile IPv6 bootstrapping work aims to make this information dynamically available to the mobile node. An important aspect of the Mobile IPv6 bootstrapping solution is to support interworking with existing authentication, authorization and accounting infrastructure. This document describes the usage of Diameter to facilitate Mobile IPv6 bootstrapping for the NAS - HAAA interface. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology and Abbreviations . . . . . . . . . . . . . . . . 3 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Commands, AVPs and Advertising Application Support . . . . . . 6 4.1. Advertising Application Support . . . . . . . . . . . . . 6 4.2. Command Codes . . . . . . . . . . . . . . . . . . . . . . 6 4.3. Diameter-EAP-Request (DER) . . . . . . . . . . . . . . . . 7 4.4. Diameter-EAP-Answer (DEA) . . . . . . . . . . . . . . . . 7 4.5. AA-Request (AAR) . . . . . . . . . . . . . . . . . . . . . 8 4.6. AA-Answer (AAA) . . . . . . . . . . . . . . . . . . . . . 9 4.7. New AVPs . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.7.1. MIP6-Home-Agent-Address AVP . . . . . . . . . . . . . 10 4.7.2. MIP6-Home-Agent-FQDN AVP . . . . . . . . . . . . . . . 10 4.7.3. MIP6-Home-Link-Prefix AVP . . . . . . . . . . . . . . 10 4.7.4. MIP4-Home-Agent-Address AVP . . . . . . . . . . . . . 11 4.8. Capability Advertisement . . . . . . . . . . . . . . . . . 11 5. Diameter Client and Server Behavior During MIPv6 Bootstrapping . . . . . . . . . . . . . . . . . . . . . . . . 11 5.1. Client (NAS) Behavior . . . . . . . . . . . . . . . . . . 12 5.2. Server Behavior . . . . . . . . . . . . . . . . . . . . . 13 5.3. Example Message Flows . . . . . . . . . . . . . . . . . . 14 6. AVP Occurrence Tables . . . . . . . . . . . . . . . . . . . . 15 6.1. DER and DEA Commands AVP Table . . . . . . . . . . . . . . 15 6.2. AAR and AAA Commands AVP Table . . . . . . . . . . . . . . 16 7. MIPv6 Bootstrapping NAS - HAAA Interface AVPs . . . . . . . . 16 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 9. Security Considerations . . . . . . . . . . . . . . . . . . . 17 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17 11. Revision history . . . . . . . . . . . . . . . . . . . . . . . 18 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18 12.1. Normative References . . . . . . . . . . . . . . . . . . . 18 12.2. Informative References . . . . . . . . . . . . . . . . . . 19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19 Intellectual Property and Copyright Statements . . . . . . . . . . 21 Korhonen (ed.), et al. Expires December 3, 2006 [Page 2] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 1. Introduction Mobile IPv6 specification [RFC3775] requires a Mobile Node (MN) to perform registration with a home agent with information about its current point of attachment (Care-of Address). The home agent creates and maintains binding between the MN's Home Address and the MN's Care-of Address. In order to register with a home agent, the MN needs to know some information such as, the Home Link prefix, the home agent Address, the Home Address(es), the Home Link prefix Length and security related information in order to later secure the Binding Update. The aforementioned set of information may be statically provisioned in the MN. However, static provisioning of this information has its drawbacks. It increases provisioning and network maintenance becomes easily burden for an operator. Moreover, static provisioning does not allow load balancing, failover, opportunistic home link assignment etc. For example, the user may be accessing the network from a location that may be geographically far away from the preconfigured home link; the administrative burden to configure the MNs with the respective addresses is large and the ability to react on environmental changes is minimal. In these situations static provisioning may not be desirable. Dynamic assignment of Mobile IPv6 home registration information is a desirable feature for ease of deployment and network maintenance. For this purpose, the Diameter infrastructure, which is used for access authentication, can be leveraged to assign some or all of the necessary parameters. The Diameter server in Access Service Provider's (ASP) or in Mobility Service Provider's (MSP) network may return these parameters to the AAA client. Regarding the bootstrapping procedures, the AAA client might either be the NAS, in case of the integrated scenario, or the home agent, in case of the split scenario [I-D.ietf-mip6-bootstrapping-split]. The terms integrated and split are described in the terminology section and were introduced in [RFC4640] and [I-D.ietf-mip6-aaa-ha-goals]. 2. Terminology and Abbreviations 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 RFC2119 [RFC2119]. General mobility terminology can be found in [RFC3753]. The following additional terms, as defined in [RFC4640], are used in this document: Korhonen (ed.), et al. Expires December 3, 2006 [Page 3] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 Access Service Authorizer (ASA): A network operator that authenticates a mobile node and establishes the mobile node's authorization to receive Internet service. Access Service Provider (ASP): A network operator that provides direct IP packet forwarding to and from the mobile node. Mobility Service Authorizer (MSA): A service provider that authorizes Mobile IPv6 service. Mobility Service Provider (MSP): A service provider that provides Mobile IPv6 service. In order to obtain such service, the mobile node must be authenticated and authorized to obtain the Mobile IPv6 service. Split scenario: A scenario where the mobility service and the network access service are authorized by different entities. Integrated Scenario: A scenario where the mobility service and the network access service are authorized by the same entity. Network Access Server (NAS): A device that provides an access service for a user to a network. Home AAA (HAAA): An authentication, authorization and accounting server located in user's home network. 3. Overview This document addresses the authentication, authorization and accounting functionality required by for the MIPv6 bootstrapping as outlined in the MIPv6 bootstrapping problem statement document (see [RFC4640]). This document focuses on the AAA functionality for the NAS - HAAA interface. Korhonen (ed.), et al. Expires December 3, 2006 [Page 4] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 The subsequent text outlines the AAA interaction between the participating entities in the integrated scenario. In the integrated scenario MIPv6 bootstrapping is provided as part of the network access authentication procedure. Figure 1 shows the participating entities. This document, however, only concentrates on the NAS, possible local Diameter proxies and the home Diameter server. +---------------------------+ +-----------------+ |Access Service Provider | |ASA/MSA/(MSP) | |(Mobility Service Provider)| | | | | | | | +--------+ | | +--------+ | | |Local | Diameter | | |Home | | | |Diameter|<---------------------->|Diameter| | | |Proxy | | | |Server | | | +--------+ | | +--------+ | | ^ | | ^ | | | | | | | | | | | | | | |Diameter | | v | | | +-------+ | | +-------+ | | | |Home | | | |Home | | | | +---->|Agent | | | |Agent | | | | | |in ASP | | | |in MSP | | | v v +-------+ | | +-------+ | +-------+ IEEE | +-----------+ +-------+ | +-----------------+ |Mobile | 802.1X | |NAS/Relay | |DHCPv6 | | |Node |----------+-|Diameter |---|Server | | | | PANA,... | |Client | | | | +-------+ DHCP | +-----------+ +-------+ | +---------------------------+ Figure 1: Mobile IPv6 Bootstrapping in the Integrated Scenario In a typical Mobile IPv6 access scenario, as shown above, the MN is attached to an ASP's network. During the network attachment procedure, the NAS/Diameter client interacts with the mobile node. As shown in Figure 1, the authentication and authorization happens via the Diameter infrastructure. At the time of authentication the user for the network access, the Diameter server in the MSA detects that the user is also authorized for Mobile IPv6 access. Based on the MSA's policy, the Diameter server may allocate several parameters to the MN for use during the subsequent Mobile IPv6 protocol interaction with the home agent. Depending on the details of the solution interaction with the DHCPv6 Korhonen (ed.), et al. Expires December 3, 2006 [Page 5] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 server may be required, as described in [I-D.ietf-mip6-bootstrapping-integrated-dhc]. However, the solution described in this document is not dependant on the DHCPv6 as the only possible MIPv6 bootstrapping method. 4. Commands, AVPs and Advertising Application Support This section describes command codes, defines AVPs and advertised application identifiers for the Diameter MIPv6 bootstrapping in the NAS - HAAA interface. 4.1. Advertising Application Support Diameter nodes conforming to this specification SHOULD include the value of 1 (NASREQ application) or 5 (EAP application) in the Auth- Application-Id or the Acct-Application-Id AVP of the Capabilities- Exchange-Request and Capabilities-Exchange-Answer commands [RFC3588]. The value of zero (0) SHOULD be used as the Application-Id in all STR/STA, ACR/ACA, ASR/ASA, and RAR/RAA commands, because these commands are defined in the Diameter base protocol and no additional mandatory AVPs for those commands are defined in this document. 4.2. Command Codes This document re-uses the Diameter Base protocol [RFC3588], Diameter NASREQ application [RFC4072] and EAP commands . The following commands are used to carry MIPv6 related bootstrapping AVPs: Command-Name Abbrev. Code Reference Application Diameter-EAP-Request DER 268 RFC 4072 EAP Diameter-EAP-Answer DEA 268 RFC 4072 EAP AA-Request AAR 265 RFC 4005 NASREQ AA-Answer AAA 265 RFC 4005 NASREQ Figure 2: MIPv6 Bootstrapping NAS - HAAA Interface Command Codes When the Re-Auth-Request (RAR), Re-Auth-Answer (RAA), Session- Termination-Request (STR), Session-Termination-Answer (STA), Abort- Session-Request (ASR), Abort-Session-Answer (ASA), Accounting-Request (ACR), and Accounting-Answer (ACA) commands are used together with the Diameter MIPv6 bootstrapping NAS - HAAA interface, they follow the rules in the Diameter NASREQ [RFC4005], EAP [RFC4072] and BASE Korhonen (ed.), et al. Expires December 3, 2006 [Page 6] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 [RFC3588] applications. The accounting commands use Application Identifier value of 3 (Diameter Base Accounting); the others use 0 (Diameter Common Messages). 4.3. Diameter-EAP-Request (DER) The Diameter-EAP-Request (DER) command [RFC4072], indicated by the Command-Code field set to 268 and the 'R' bit set in the Command Flags field, may be sent by the NAS to the Diameter server providing network access authentication and authorization services. At the same time with the network access authentication and authorization the NAS MAY indicate the access network capability of MIPv6 bootstrapping and optionally also the capability of a local home agent assignment. The message format is the same as defined in [RFC4072] with an addition of possible MIPv6 bootstrapping NAS - HAAA interface AVPs to indicate capabilities of the NAS and ASP: ::= < Diameter Header: 268, REQ, PXY > < Session-Id > { Auth-Application-Id } { Origin-Host } { Origin-Realm } { Destination-Realm } { Auth-Request-Type } [ MIP6-Home-Agent-Address ] [ MIP6-Home-Agent-FQDN ] [ MIP6-Home-Link-Prefix ] [ MIP4-Home-Agent-Address ] [ Destination-Host ] ... * [ AVP ] Figure 3: Diameter EAP Request Command 4.4. Diameter-EAP-Answer (DEA) The Diameter-EAP-Answer (DEA) message define in [RFC4072], indicated by the Command-Code field set to 268 and 'R' bit cleared in the Command Flags field is sent in response to the Diameter-EAP-Request message (DER). If the network access was successfully authenticated then the response SHOULD include the MIP6-Home-Agent-Address AVP, MIP6-Home-Link-Prefix, MIP6-Home-Agent-FQDN and MIP4-Home-Agent- Korhonen (ed.), et al. Expires December 3, 2006 [Page 7] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 address AVPs. The message format is the same as defined in [RFC4072] with an addition of MIPv6 bootstrapping NAS - HAAA interface AVPs: ::= < Diameter Header: 268, PXY > < Session-Id > { Auth-Application-Id } { Auth-Request-Type } { Result-Code } { Origin-Host } { Origin-Realm } [ MIP6-Home-Agent-Address ] [ MIP6-Home-Agent-FQDN ] [ MIP6-Home-Link-Prefix ] [ MIP4-Home-Agent-Address ] [ User-Name ] ... * [ AVP ] Figure 4: Diameter EAP Answer Command 4.5. AA-Request (AAR) The AA-Request (AAR) message, indicated by the Command-Code field set to 265 and 'R' bit set in the Command Flags field, may be sent by the NAS to the Diameter server providing network access configuration services. At the same time with the network access configuration the NAS MAY request home agent assignment, to authorize for mobility service usage and optionally to indicate the support of possible local home agent assignment. The message format is the same as defined in [RFC4005] with an addition of MIPv6 bootstrapping NAS - HAAA interface AVPs: Korhonen (ed.), et al. Expires December 3, 2006 [Page 8] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 ::= < Diameter Header: 265, REQ, PXY > < Session-Id > { Auth-Application-Id } { Origin-Host } { Origin-Realm } { Destination-Realm } { Auth-Request-Type } [ MIP6-Home-Agent-Address ] [ MIP6-Home-Agent-FQDN ] [ MIP6-Home-Link-Prefix ] [ MIP4-Home-Agent-Address ] [ Destination-Host ] ... * [ AVP ] Figure 5: AA Request Command 4.6. AA-Answer (AAA) The AA-Answer (AAA) message, indicated by the Command-Code field set to 265 and 'R' bit cleared in the Command Flags field is sent in response to the AA-Request (AAR) message for confirmation of the result of MIPv6 HA bootstrapping. If the network access was successfully authenticated then the response SHOULD include the MIP6- Home-Agent-Address AVP, MIP6-Home-Link-Prefix, MIP6-Home-Agent-FQDN and MIP4-Home-Agent-address AVPs. The message format is the same as defined in [RFC4005] with an addition of MIPv6 bootstrapping NAS - HAAA interface AVPs: Korhonen (ed.), et al. Expires December 3, 2006 [Page 9] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 ::= < Diameter Header: 265, PXY > < Session-Id > { Auth-Application-Id } { Auth-Request-Type } { Result-Code } { Origin-Host } { Origin-Realm } [ MIP6-Home-Agent-Address ] [ MIP6-Home-Agent-FQDN ] [ MIP6-Home-Link-Prefix] [ MIP4-Home-Agent-address ] [ User-Name ] ... * [ AVP ] Figure 6: AA Answer Command 4.7. New AVPs 4.7.1. MIP6-Home-Agent-Address AVP The MIP6-Home-Agent-Address AVP (AVP Code TBD) is of type OctetString and contains the Mobile IPv6 home agent address and the prefix length of the said address. The AVP is a discriminated union, representing IPv6 address in network byte order. The first two octets of this AVP represents the home link prefix length followed by 16 octets of the IPv6 address. The Diameter server MAY decide to assign a MIPv6 home agent to the MN that is in close proximity to the point of attachment (e.g. determined by the NAS-Identifier). There may be other reasons for dynamically assigning home agents to the MN, for example to share the traffic load. The AVP also contains the prefix length so that the MN can easily infer one of the possible Home Link prefixes from the home agent address. 4.7.2. MIP6-Home-Agent-FQDN AVP The MIP6-Home-Agent-FQDN AVP (AVP Code TBD) is of type UTF8String and contains the FQDN of a Mobile IPv6 home agent. 4.7.3. MIP6-Home-Link-Prefix AVP The MIP6-Home-Link-Prefix AVP (AVP Code TBD) is of type OctetString and contains the Mobile IPv6 home link prefix. There may be reasons for the Diameter server to dynamically assigning home link prefix to Korhonen (ed.), et al. Expires December 3, 2006 [Page 10] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 the MN, for example one that is in close proximity to the point of attachment. 4.7.4. MIP4-Home-Agent-Address AVP The MIP4-Home-Agent-Address AVP (AVP Code TBD) is of type OctetString and contains the IPv4 home agent address and the prefix length of the said address. The AVP is a discriminated union, representing IPv4 address in network byte order. The first two octets of this AVP represents the home link prefix length followed by 4 octets of the IPv4 address. The Diameter server MAY decide to assign a MIPv4 home agent to the MN in a case where dual stack Mobile IP is supported [I-D.ietf-mip6-nemo-v4traversal]. 4.8. Capability Advertisement The NAS/ASP may include any MIPv6 bootstrapping AVPs in the Diameter EAP or NASREQ application request messages to advertise its MIPv6 bootstrapping capabilities to the Diameter server. The use of capability advertisement is optional. The capability advertisement may also be used as an explicit hint to the Diameter server about locally allocated mobility agents or home links. In this case e.g. the MIP6-Home-Agent-Address AVP would contain the IP address of the locally allocated home agent. If the NAS/ASP does not have any specific home agent to offer during the access authentication time the IP address in the respective bootstrapping AVPs MUST be set to unspecified address (::/128). The MIP6-Home-Agent-FQDN SHOULD NOT be used for the capability advertisement if it does not already name a locally allocated Home Agent. 5. Diameter Client and Server Behavior During MIPv6 Bootstrapping This section describes the Diameter server and client behavior in case of the MIPv6 bootstrapping in the integrated scenario. The text does several assumptions for brevity. o The Diameter server is assumed to support at least the Diameter BASE, EAP and NASREQ applications. o The Diameter client (i.e. the NAS) is assumed to support at least the Diameter BASE, EAP and NASREQ applications. Korhonen (ed.), et al. Expires December 3, 2006 [Page 11] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 o The MN uses such network access authentication method and credentials that are supported by the NAS/ASP and ASA/MSA. o The MN has been provisioned with a Mobile IPv6 service. o The capability exchange has already completed, thus the NAS and the Diameter server share the knowledge of mutually supported applications. Cases where the ASA/MSA do not support MIPv6 bootstrapping are not discussed. In these cases the NAS has no other choice than to carry out the network access authentication as defined in the Diameter EAP or NASREQ applications. 5.1. Client (NAS) Behavior If the ASP/NAS does not support MIPv6 integrated scenario bootstrapping then the NAS either selects the basic Diameter NASREQ or EAP application depending on which authentication method gets used. Naturally after a successful or a failed authentication the NAS does not have to carry out any MIPv6 bootstrapping related procedures. Next we describe two different scenarios for the network access authentication when the ASP/NAS supports MIPv6 integrated scenario bootstrapping. 1) The MN uses some EAP-based method (e.g. 802.11i/802.1X) to authenticate to the network. In this scenario the NAS uses commands originally defined for the EAP application. 2) The MN uses some other than EAP-based method to authenticate to the network. In this scenario the NAS uses the Diameter NASREQ application commands. The NAS may include the MIPv6 NAS - HAAA AVPs in the DER or in the AAR messages. This serves two purposes. Firstly the NAS/ASP may advertise its MIPv6 bootstrapping capability to the Diameter server. Secondly the NAS/ASP may suggest locally allocated home agents to the Diameter server. Whether the locally allocated home agents are allowed for the forthcoming MIPv6 session depends on the MN's subscription and the ASA/MSA(/MSP) policies. If the NAS/ASP only wants to advertise its capability for local agent allocation but does not want to provide any specific agent at this point of time (e.g. that is left for later steps during the actual Mobile IP registration) the AVPs MUST contain values described in Section 4.8. If the network access authentication failed the NAS receives appropriate error codes as defined for the Diameter EAP or NASREQ applications. The NAS does not allow the MN to access the network and does not do any MIPv6 bootstrapping related procedures. If the network access authentication completed successfully, the NAS Korhonen (ed.), et al. Expires December 3, 2006 [Page 12] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 looks for home agent defining AVPs in the reply messages (either DEA or AAA depending on the used authentication method). The NAS associates the received bootstrapping information to the MN that initiated the access authentication and stores the information internally (storing time is determined by the ASP policy). The stored bootstrapping information is then available for the NAS and the DHCP relay for later step during the MN bootstrapping process. The actual bootstrapping from the MN point of view takes place after the network access authentication has completed. The bootstrapping may be realized e.g. using DHCP as defined in [I-D.ietf-mip6-bootstrapping-integrated-dhc] and [RFC2132]. The MN has no consistent way of indicating to the NAS that it supports MIPv6 integrated scenario way of bootstrapping during the network access authentication. Subsequently the NAS has no possibilities to find out whether the terminal attempting to authenticate is actually a MN with MIPv6 bootstrapping functionality prior the network access authentication has completed. Thus it is possible that the NAS initiates MIPv6 integrated scenario bootstrapping configuration even if the MN is not able to make any use of it later. The Diameter server in the ASA/MSA might be able to detect this situation during the authentication phase based on MN's identity -- assuming the ASA is able to verify from the MSA(/MSP) whether the MN has been provisioned with a MIPv6 service. 5.2. Server Behavior If the NAS/ASP does not support MIPv6 integrated scenario bootstrapping then the NAS either selects the Diameter NASREQ or EAP application depending on which access authentication method the MN has to use to authenticate. In this case the NAS does not either include any MIPv6 NAS - HAAA interface AVPs as a hint of the bootstrapping capability in the NAS/ASP. The Diameter server in the ASA/MSA(/MSP) detects this case (based on AVPs that serve as a capability hint) and does not have to carry out any MIPv6 bootstrapping related procedures. However, as the capability advertisement mechanism described in this document serves only as an optional hint, the Diameter server should not entirely rely on the received capability hints but also base its working logic on subscription information and general MSA(/MSP) policies. Next we describe two different scenarios for the network access authentication when the NAS/ASP supports MIPv6 integrated scenario bootstrapping. Korhonen (ed.), et al. Expires December 3, 2006 [Page 13] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 1) The MN uses some EAP-based method to authenticate to the network and the NAS uses Diameter EAP application commands. Depending on the ASA/MSA(/MSP) policy the Diameter server SHOULD assign a Mobile IPv6 home agent to the MN and include corresponding MIP6- Home-Agent-Address, the MIP6-Home-Agent-FQDN AVPs and the MIP6- Home-Link-Prefix in the final DEA message. 2) The MN uses some other than EAP-based method to authenticate to the network and the NAS uses Diameter NASREQ application commands. Depending on the ASA/MSA(/MSP) policy the Diameter server SHOULD assign a Mobile IPv6 home agent to the MN and include corresponding MIP6-Home-Agent-Address, the MIP6-Home-Agent-FQDN AVPs and the MIP6-Home-Link-Prefix in the final AAA message. If the Diameter request message contained any MIPv6 NAS -HAAA interface AVPs the Diameter server should regard them as a hint of the MIPv6 bootstrapping capability in the NAS/ASP. Any of these AVPs may contain values as described in Section 4.8 which indicate the NAS/ASP would like to locally allocate a home agent or a home link to the MN. The Diameter server may or may not honor the NAS/ASP hint based on the MN's subscription and ASA/MAS(/MSP) policies. 5.3. Example Message Flows This section shows basic message flows of MIPv6 integrated scenario bootstrapping and dynamic home agent assignment. In the Figure 7 network access authentication is based on EAP (e.g. 802.11i/802.1X). The NAS informs the home Diameter server that home agent assignment in the foreign network is possible. The Diameter server assigns the MN a home agent either in the home MSP or in the ASP. The assignment procedure is out of scope of this document. The Diameter server then replies to the NAS with home agent related bootstrapping information. Korhonen (ed.), et al. Expires December 3, 2006 [Page 14] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 NAS Local proxy Home server | | | | Diameter-EAP-Request | | | MIP6-Home-Agent-Address(IPv6 address) | | MIP6-Home-Agent-FQDN=visited_ha6.example.com | | MIP4-Home-Agent-Address(IPv4 address) | | MIP6-Home-Link-Prefix=(IPv6 prefix) | | Auth-Request-Type=AUTHORIZE_AUTHENTICATE | | EAP-Payload(EAP Start) | | |------------------------------->|------------------------------->| | | | | : | : ...more EAP Request/Response pairs... : | : | | | | | | Diameter-EAP-Answer | | MIP6-Home-Agent-Address(IPv6 address) | | MIP6-Home-Agent-FQDN=ha.example.com | | | Result-Code=DIAMETER_SUCCESS | | | EAP-Payload(EAP Success) | | | EAP-Master-Session-Key | | | (authorization AVPs) | | | ... | |<-------------------------------|<-------------------------------| | | | Figure 7: MIPv6 integrated scenario bootstrapping and NAS - HAAA interface example when EAP is used for access authentication 6. AVP Occurrence Tables 6.1. DER and DEA Commands AVP Table The following table lists the additional MIPv6 bootstrapping NAS - HAAA interface AVPs that optionally may be present in the DER and DEA Commands, as defined in this document and in [RFC4072]. Korhonen (ed.), et al. Expires December 3, 2006 [Page 15] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 +---------------+ | Command-Code | |-------+-------+ Attribute Name | DER | DEA | -------------------------------+-------+-------+ MIP6-Home-Agent-Address | 0-1 | 0-1 | MIP6-Home-Agent-FQDN | 0-1 | 0-1 | MIP4-Home-Agent-Address | 0-1 | 0-1 | MIP6-Home-Link-Prefix | 0-1 | 0-1 | +-------+-------+ Figure 8: DER and DEA Commands AVP table 6.2. AAR and AAA Commands AVP Table The following table lists the additional MIPv6 bootstrapping NAS - HAAA interface AVPs that may optionally be present in the AAR and AAA Commands, as defined in this document and in [RFC4005]. +---------------+ | Command-Code | |-------+-------+ Attribute Name | AAR | AAA | -------------------------------|-------+-------| MIP6-Home-Agent-Address | 0-1 | 0-1 | MIP6-Home-Agent-FQDN | 0-1 | 0-1 | MIP4-Home-Agent-Address | 0-1 | 0-1 | MIP6-Home-Link-Prefix | 0-1 | 0-1 | +-------+-------+ Figure 9: AAR and AAA Commands AVP table 7. MIPv6 Bootstrapping NAS - HAAA Interface AVPs This section defines the AVPs that are specific to Diameter MIPv6 bootstrapping NAS - HAAA interface and MAY be included in the Diameter EAP [RFC4072] and the NASREQ [RFC4005] applications messages listed in Section 4 of this document. The Diameter AVP rules are defined in the Diameter Base [RFC3588], Section 4. These AVP rules are observed in AVPs defined in this section. The following table describes the Diameter AVPs, their AVP Code values, types, possible flag values, and whether the AVP MAY be encrypted. The Diameter base [RFC3588] specifies the AVP Flag rules Korhonen (ed.), et al. Expires December 3, 2006 [Page 16] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 for AVPs in section 4.5. +--------------------+ | AVP Flag rules | +----+-----+----+----+----+ AVP Section | | |SHLD|MUST| | Attribute Name Code Defined Data Type |MUST| MAY | NOT|NOT |Encr| -----------------------------------------+----+-----+----+----+----+ MIP6-Home-Agent- TBD 4.7.1 OctetString| M | P | | V | Y | Address | | | | | | MIP6-Home-Agent- TBD 4.7.2 UTF8String | M | P | | V | Y | FQDN | | | | | | MIP4-Home-Agent- TBD 4.7.4 OctetString| M | P | | V | Y | address | | | | | | MIP6-Home-Link- TBD 4.7.3 Unsigned32 | M | P | | V | Y | Prefix | | | | | | -----------------------------------------+----+-----+----+----+----+ Figure 10: AVP flag rules table 8. IANA Considerations This specification defines the following new AVPs: MIP6-Home-Agent-Address is set to TBD MIP6-Home-Agent-FQDN is set to TBD MIP4-Home-Agent-Address is set to TBD MIP6-Home-Link-Prefix is set to TBD 9. Security Considerations The security considerations for the Diameter interaction required to accomplish the integrated scenario are described in [I-D.ietf-mip6-bootstrapping-integrated-dhc] . Additionally, the security considerations of the Diameter base protocol [RFC3588], Diameter NASREQ application [RFC4005] / Diameter EAP [RFC4072] application (with respect to network access authentication and the transport of keying material) are applicable to this document. 10. Acknowledgements This document is heavily based on the ongoing work for RADIUS MIPv6 interaction. Hence, credits go to respective authors for their work with draft-ietf-mip6-radius-00.txt. Furthermore, the author would like to thank the authors of draft-le-aaa-diameter-mobileipv6-04.txt Korhonen (ed.), et al. Expires December 3, 2006 [Page 17] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 (Franck Le, Basavaraj Patil, Charles E. Perkins, Stefano Faccin) for their work in context of MIPv6 Diameter interworking. Their work influenced this document. 11. Revision history The following changes were made to the -01 version of the draft: o The document title was changed to "The NAS - HAAA Interface for MIPv6 Bootstrapping". o Added HAAA and NAS to terminology section". o Changed NAS application to NASREQ application.". o Changed "Integrated Scenario" to NAS-HAAA interface". o The separate Diameter Application-ID for MIPv6 bootstrapping (MIP6BSTI) got removed and all bootstrapping is based on Diameter EAP application and Diameter NAS application. o MIPv6-Bootstrapping-Feature AVP was removed and General text regarding to the capability advertisement based on optional AVPs was added. o The capability exchange was modified so that the NAS may suggest a specific HA to the AAAH. Original MIPv6-Bootstrapping-Feature AVP was replaces with a possibility to include any bootstrapping AVP to the Diameter AAR or DER messages as a capability and local allocation hint. 12. References 12.1. Normative References [I-D.ietf-mip6-aaa-ha-goals] Giaretta, G., "AAA Goals for Mobile IPv6", draft-ietf-mip6-aaa-ha-goals-03 (work in progress), September 2006. [I-D.ietf-mip6-bootstrapping-integrated-dhc] Chowdhury, K. and A. Yegin, "MIP6-bootstrapping via DHCPv6 for the Integrated Scenario", draft-ietf-mip6-bootstrapping-integrated-dhc-01 (work in progress), June 2006. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", March 1997. [RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. Arkko, "Diameter Base Protocol", RFC 3588, September 2003. Korhonen (ed.), et al. Expires December 3, 2006 [Page 18] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 [RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004. [RFC4640] Patel, A. and G. Giaretta, "Problem Statement for bootstrapping Mobile IPv6 (MIPv6)", RFC 4640, September 2006. 12.2. Informative References [I-D.ietf-mip6-bootstrapping-split] Giaretta, G., "Mobile IPv6 bootstrapping in split scenario", draft-ietf-mip6-bootstrapping-split-03 (work in progress), October 2006. [I-D.ietf-mip6-nemo-v4traversal] Soliman, H., "Mobile IPv6 support for dual stack Hosts and Routers (DSMIPv6)", draft-ietf-mip6-nemo-v4traversal-02 (work in progress), June 2006. [RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor Extensions", RFC 2132, March 1997. [RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology", RFC 3753, June 2004. [RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton, "Diameter Network Access Server Application", RFC 4005, August 2005. [RFC4072] Eronen, P., Hiller, T., and G. Zorn, "Diameter Extensible Authentication Protocol (EAP) Application", RFC 4072, August 2005. Authors' Addresses Jouni Korhonen TeliaSonera Teollisuuskatu 13 Sonera FIN-00051 Finland Email: jouni.korhonen@teliasonera.com Korhonen (ed.), et al. Expires December 3, 2006 [Page 19] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 Julien Bournelle GET/INT 9 rue Charles Fourier Evry 91011 France Email: julien.bournelle@int-evry.fr Hannes Tschofenig Siemens Otto-Hahn-Ring 6 Munich, Bavaria 81739 Germany Email: Hannes.Tschofenig@siemens.com URI: http://www.tschofenig.com Charles E. Perkins Nokia Email: charliep@iprg.nokia.com Kuntal Chowdhury Starent Networks Email: kchowdhury@starentnetworks.com Korhonen (ed.), et al. Expires December 3, 2006 [Page 20] Internet-Draft Diameter MIPv6 NAS - HAAA Interface June 2006 Full Copyright Statement Copyright (C) The Internet Society (2006). 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. 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