AAA Working Group Pat R. Calhoun Internet-Draft Airespace Inc. Category: Standards Track Glen Zorn Cisco Systems Inc. David Spence Interlink Networks Inc. David Mitton Circular Logic Oct 2003 Diameter Network Access Server Application draft-ietf-aaa-diameter-nasreq-13.txt Status of this Memo 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. This document is a product of the Authentication, Authorization and Accounting (AAA) Working Group of the Internet Engineering Task Force (IETF). Comments are welcome should be submitted to the mailing list aaa-wg@merit.edu. Copyright (C) The Internet Society 2003. All Rights Reserved. Calhoun et al. Expires Apr 2004 [Page 1] INTERNET-DRAFT Diameter NAS Application Oct 2003 Abstract This document describes the Diameter protocol application used for Authentication, Authorization and Accounting (AAA) services in the Network Access Server (NAS) environment. This application specification, when combined with the Diameter Base protocol, Transport Profile, and Extensible Authentication Protocol specifications, satisfies typical network access services requirements. Initial deployments of the Diameter protocol are expected to include legacy systems. Therefore, this application was carefully designed to ease the burden of protocol conversion between RADIUS and Diameter. This is achieved by including the RADIUS attribute space, and eliminating the need to perform many attribute translations. Calhoun et al. Expires Apr 2004 [Page 2] INTERNET-DRAFT Diameter NAS Application Oct 2003 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . 6 1.2. Requirements Language . . . . . . . . . . . . . . . . . 7 1.3. Advertising Application Support . . . . . . . . . . . . 7 2. NAS Calls, Ports, and Sessions . . . . . . . . . . . . . . . . . 7 2.1. Diameter Session Establishment . . . . . . . . . . . . . 8 2.2. Diameter Session Reauthentication or Reauthorization . . 8 2.3. Diameter Session Termination . . . . . . . . . . . . . . 9 3. NAS Messages . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1. AA-Request (AAR) Command . . . . . . . . . . . . . . . . 10 3.2. AA-Answer (AAA) Command . . . . . . . . . . . . . . . . 11 4. NAS Session AVPs . . . . . . . . . . . . . . . . . . . . . . . . 13 4.1. Call and Session Information . . . . . . . . . . . . . . 14 4.2. NAS-Port AVP . . . . . . . . . . . . . . . . . . . . . . 14 4.3. NAS-Port-Id AVP . . . . . . . . . . . . . . . . . . . . 15 4.4. NAS-Port-Type AVP . . . . . . . . . . . . . . . . . . . 15 4.5. Called-Station-Id AVP . . . . . . . . . . . . . . . . . 16 4.6. Calling-Station-Id AVP . . . . . . . . . . . . . . . . . 16 4.7. Connect-Info AVP . . . . . . . . . . . . . . . . . . . . 17 4.8. Originating-Line-Info AVP . . . . . . . . . . . . . . . 17 4.9. Reply-Message AVP . . . . . . . . . . . . . . . . . . . 18 5. NAS Authentication AVPs . . . . . . . . . . . . . . . . . . . . 19 5.1. User-Password AVP . . . . . . . . . . . . . . . . . . . 19 5.2. Password-Retry AVP . . . . . . . . . . . . . . . . . . . 20 5.3. Prompt AVP . . . . . . . . . . . . . . . . . . . . . . . 20 5.4. CHAP-Auth AVP . . . . . . . . . . . . . . . . . . . . . 20 5.5. CHAP-Algorithm AVP . . . . . . . . . . . . . . . . . . . 20 5.6. CHAP-Ident AVP . . . . . . . . . . . . . . . . . . . . . 21 5.7. CHAP-Response AVP . . . . . . . . . . . . . . . . . . . 21 5.8. CHAP-Challenge AVP . . . . . . . . . . . . . . . . . . . 21 5.9. ARAP-Password AVP . . . . . . . . . . . . . . . . . . . 21 5.10. ARAP-Challenge-Response AVP . . . . . . . . . . . . . . 21 5.11. ARAP-Security AVP . . . . . . . . . . . . . . . . . . . 22 5.12. ARAP-Security-Data AVP . . . . . . . . . . . . . . . . 22 6. NAS Authorization AVPs . . . . . . . . . . . . . . . . . . . . . 22 6.1. Service-Type AVP . . . . . . . . . . . . . . . . . . . . 23 6.2. Callback-Number AVP . . . . . . . . . . . . . . . . . . 25 6.3. Callback-Id AVP . . . . . . . . . . . . . . . . . . . . 25 6.4. Idle-Timeout AVP . . . . . . . . . . . . . . . . . . . . 25 6.5. Port-Limit AVP . . . . . . . . . . . . . . . . . . . . . 25 6.6. NAS-Filter-Rule AVP . . . . . . . . . . . . . . . . . . 26 6.7. Filter-Id AVP . . . . . . . . . . . . . . . . . . . . . 26 6.8. Configuration-Token AVP . . . . . . . . . . . . . . . . 26 6.9. Framed Access Authorization AVPs . . . . . . . . . . . . 26 6.9.1. Framed-Protocol AVP . . . . . . . . . . . . . 26 Calhoun et al. Expires Apr 2004 [Page 3] INTERNET-DRAFT Diameter NAS Application Oct 2003 6.9.2. Framed-Routing AVP . . . . . . . . . . . . . . 27 6.9.3. Framed-MTU AVP . . . . . . . . . . . . . . . . 27 6.9.4. Framed-Compression AVP . . . . . . . . . . . . 27 6.10. IP Access . . . . . . . . . . . . . . . . . . . . . . . 28 6.10.1. Framed-IP-Address AVP . . . . . . . . . . . . 28 6.10.2. Framed-IP-Netmask AVP . . . . . . . . . . . . 28 6.10.3. Framed-Route AVP . . . . . . . . . . . . . . 28 6.10.4. Framed-Pool AVP . . . . . . . . . . . . . . . 29 6.10.5. Framed-Interface-Id AVP . . . . . . . . . . . 29 6.10.6. Framed-IPv6-Prefix AVP . . . . . . . . . . . 29 6.10.7. Framed-IPv6-Route AVP . . . . . . . . . . . . 30 6.10.8. Framed-IPv6-Pool AVP . . . . . . . . . . . . 30 6.11. IPX Access . . . . . . . . . . . . . . . . . . . . . . 30 6.11.1. Framed-IPX-Network AVP . . . . . . . . . . . 30 6.12. Appletalk Access . . . . . . . . . . . . . . . . . . . 31 6.12.1. Framed-AppleTalk-Link AVP . . . . . . . . . . 31 6.12.2. Framed-AppleTalk-Network AVP . . . . . . . . 31 6.12.3. Framed-AppleTalk-Zone AVP . . . . . . . . . . 32 6.13. ARAP Access . . . . . . . . . . . . . . . . . . . . . . 32 6.13.1. ARAP-Features AVP . . . . . . . . . . . . . . 32 6.13.2. ARAP-Zone-Access AVP . . . . . . . . . . . . 32 6.14. Non-Framed Access Authorization AVPs . . . . . . . . . 32 6.14.1. Login-IP-Host AVP . . . . . . . . . . . . . . 33 6.14.2. Login-IPv6-Host AVP . . . . . . . . . . . . . 33 6.14.3. Login-Service AVP . . . . . . . . . . . . . . 33 6.15. TCP Services . . . . . . . . . . . . . . . . . . . . . 34 6.15.1. Login-TCP-Port AVP . . . . . . . . . . . . . 34 6.15.2. LAT Services . . . . . . . . . . . . . . . . 34 6.15.3. Login-LAT-Service AVP . . . . . . . . . . . . 34 6.15.4. Login-LAT-Node AVP . . . . . . . . . . . . . 35 6.15.5. Login-LAT-Group AVP . . . . . . . . . . . . . 35 6.15.6. Login-LAT-Port AVP . . . . . . . . . . . . . 36 7. NAS Tunneling . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.1. Tunneling AVP . . . . . . . . . . . . . . . . . . . . . 37 7.2. Tunnel-Type AVP . . . . . . . . . . . . . . . . . . . . 38 7.3. Tunnel-Medium-Type AVP . . . . . . . . . . . . . . . . . 38 7.4. Tunnel-Client-Endpoint AVP . . . . . . . . . . . . . . . 39 7.5. Tunnel-Server-Endpoint AVP . . . . . . . . . . . . . . . 40 7.6. Tunnel-Password AVP . . . . . . . . . . . . . . . . . . 40 7.7. Tunnel-Private-Group-Id AVP . . . . . . . . . . . . . . 40 7.8. Tunnel-Assignment-Id AVP . . . . . . . . . . . . . . . . 41 7.9. Tunnel-Preference AVP . . . . . . . . . . . . . . . . . 42 7.10. Tunnel-Client-Auth-Id AVP . . . . . . . . . . . . . . . 43 7.11. Tunnel-Server-Auth-Id AVP . . . . . . . . . . . . . . . 43 8. NAS Accounting . . . . . . . . . . . . . . . . . . . . . . . . . 43 8.1. Accounting-Input-Octets AVP . . . . . . . . . . . . . . 44 8.2. Accounting-Output-Octets AVP . . . . . . . . . . . . . . 44 8.3. Accounting-Input-Packets AVP . . . . . . . . . . . . . . 45 Calhoun et al. Expires Apr 2004 [Page 4] INTERNET-DRAFT Diameter NAS Application Oct 2003 8.4. Accounting-Output-Packets AVP . . . . . . . . . . . . . 45 8.5. Acct-Session-Time AVP . . . . . . . . . . . . . . . . . 45 8.6. Acct-Authentic AVP . . . . . . . . . . . . . . . . . . . 45 8.7. Accounting-Auth-Method AVP . . . . . . . . . . . . . . . 46 8.8. Acct-Delay-Time . . . . . . . . . . . . . . . . . . . . 46 8.9. Acct-Link-Count . . . . . . . . . . . . . . . . . . . . 46 8.10. Acct-Tunnel-Connection AVP . . . . . . . . . . . . . . 47 8.11. Acct-Tunnel-Packets-Lost AVP . . . . . . . . . . . . . 47 9. RADIUS/Diameter Protocol Interactions . . . . . . . . . . . . . 48 9.1. RADIUS Request Forwarded as Diameter Request . . . . . . 48 9.2. Diameter Request Forwarded as RADIUS Request . . . . . . 52 9.3. AVPs Used Only for Compatibility . . . . . . . . . . . . 55 9.3.1. NAS-Identifier AVP . . . . . . . . . . . . . . 55 9.3.2. NAS-IP-Address AVP . . . . . . . . . . . . . . 56 9.3.3. NAS-IPv6-Address AVP . . . . . . . . . . . . . 57 9.3.4. State AVP . . . . . . . . . . . . . . . . . . 57 9.3.5. Termination-Cause AVP Code Values . . . . . . 58 9.4. Prohibited RADIUS Attributes . . . . . . . . . . . . . . 60 9.5. Translatable Diameter AVPs . . . . . . . . . . . . . . . 61 9.6. RADIUS Vendor Specific Attributes . . . . . . . . . . . 61 9.6.1. Forwarding a Diameter Vendor AVP as a RADIUS VS 61 9.6.2. Forwarding a RADIUS VSA to a Diameter Vendor AV 62 10. AVP Occurrence Tables . . . . . . . . . . . . . . . . . . . . . 63 10.1. AA-Request/Answer AVP Table . . . . . . . . . . . . . . 63 10.2. Accounting AVP Tables . . . . . . . . . . . . . . . . . 66 10.2.1. Accounting Framed Access AVP Table . . . . . 66 10.2.2. Accounting Non-Framed Access AVP Table . . . 67 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 69 11.1. Command Codes . . . . . . . . . . . . . . . . . . . . . 69 11.2. AVP Codes . . . . . . . . . . . . . . . . . . . . . . . 69 11.3. Application Identifier . . . . . . . . . . . . . . . . 69 11.4. CHAP-Algorithm AVP Values . . . . . . . . . . . . . . . 69 11.5. Accounting-Auth-Method AVP Values . . . . . . . . . . . 70 12. Security Considerations . . . . . . . . . . . . . . . . . . . . 70 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 70 13.1. Normative References . . . . . . . . . . . . . . . . . 70 13.2. Informative References . . . . . . . . . . . . . . . . 71 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 73 15. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 73 Intellectual Property Considerations . . . . . . . . . . . . . . . . 74 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . . 74 Calhoun et al. Expires Apr 2004 [Page 5] INTERNET-DRAFT Diameter NAS Application Oct 2003 1. Introduction This document describes the Diameter protocol application used for AAA in the Network Access Server (NAS) environment. This Diameter NAS application specification, when combined with the Diameter Base protocol [Base], Transport Profile [DiamTrans], and EAP [DiamEAP] specifications, satisfies NAS-related requirements defined in RFC2989 [AAACriteria] and RFC3169 [NASCriteria]. Initial deployments of the Diameter protocol are expected to include legacy systems. Therefore, this application was carefully designed to ease the burden of protocol conversion between RADIUS and Diameter. This is achieved by including the RADIUS attribute space, and eliminating the need to perform many attribute translations. This document first describes the operation of a Diameter NAS application. Then it defines the Diameter message Command-Codes. The following sections enumerate the AVPs used in these messages grouped by common usage. These are session identification, authentication, authorization, tunneling, and accounting. The authorization AVPs are further broken down by service type. Interaction and backwards compatibility issues with RADIUS are discussed in later sections. 1.1. Terminology The base Diameter [Base] specification Section 1.4 defines most of the terminology used in this document. Additionally, the following terms and acronyms are used in this application: NAS - Network Access Server; a device which provides an access service to a network. The service may be a network connection, or a value added service such as terminal emulation. [NASmodel] CMS - Cryptographic Message Syntax; A security method used in Diameter to secure AVPs. [DiamCMS] PPP - Point-to-Point Protocol; a multiprotocol serial datalink. PPP is the primary IP datalink used for dial-in NAS connection service. [STD51] CHAP - Challenge Handshake Authentication Protocol; an authentication process used in PPP. [PPPCHAP] PAP - Password Authentication Protocol; a deprecated PPP authentication process, but used for backwards compatibility. Calhoun et al. Expires Apr 2004 [Page 6] INTERNET-DRAFT Diameter NAS Application Oct 2003 SLIP - Serial Line Interface Protocol; a serial datalink that only supports IP. An earlier design, prior to PPP. ARAP - Appletalk Remote Access Protocol; a serial datalink for accessing Appletalk networks. IPX - Internet Packet Exchange; The network protocol used by NetWare networks. LAT - Local Area Transport; A Digital Equipment Corp. LAN protocol for terminal services. VPN - Virtual Private Network; in this document it is used to describe access services which use tunneling methods. 1.2. Requirements Language In this document, the key words "MAY", "MUST", "MUST NOT", "OPTIONAL", "RECOMMENDED", "SHOULD", and "SHOULD NOT", are to be interpreted as described in [Keywords]. 1.3. Advertising Application Support Diameter applications conforming to this specification MUST advertise support by including the value of one (1) in the Auth-Application-Id or the Acct-Application-Id AVP of the Capabilities-Exchange-Request and Capabilities-Exchange-Answer commands [Base]. 2. NAS Calls, Ports, and Sessions The arrival of a new call or service connection at a port of a Network Access Server (NAS) starts a Diameter NAS message exchange. Information about the call, the identity of the user, and the user's authentication information are packaged into a Diameter AA-Request (AAR) message and sent to a server. The server processes the information and responds with a Diameter AA- Answer (AAA) message which contains authorization information for the NAS, or a failure code (Result-Code AVP). If the value of Result- Code is DIAMETER_MULTI_ROUND_AUTH, an additional authentication exchange is indicated, and several AAR and AAA messages may be exchanged until the transaction completes. The Diameter protocol allows authorization-only requests depending on the Auth-Request-Type AVP, where no authentication information is Calhoun et al. Expires Apr 2004 [Page 7] INTERNET-DRAFT Diameter NAS Application Oct 2003 contained in a request from the client. This capability goes beyond the Call Check capabilities described in Section 5.6 of [RADIUS] in that no access decision is requested. As a result, service cannot be started as a result of a response to an authorization-only request without introducing a significant security vulnerability. Since no equivalent capability exists in RADIUS, authorization-only requests from a NAS implementing Diameter may not be easily translated to an equivalent RADIUS message by a Diameter/RADIUS gateway. For example, where a Diameter authorization-only request cannot be translated to a RADIUS Call Check, it would be necessary for the Diameter/RADIUS gateway to add authentication information to the RADIUS Access Request. On receiving the Access-Reply, the Diameter/RADIUS gateway would need to discard the access decision (Accept/Reject). It is not clear that these translations can be accomplished without adding significant security vulnerabilities. 2.1. Diameter Session Establishment When the authentication or authorization exchange completes successfully, the NAS application SHOULD start a session context. If the Result-Code of DIAMETER_MULTI_ROUND_AUTH is returned, the exchange continues until a success or error is returned. If accounting is active, the application MUST also send an Accounting message [Base]. An Accounting-Record-Type of START_RECORD, is sent for a new session. If a session fails to start, the type EVENT_RECORD message with the reason for the failure described is sent. Note that the return of an unsupportable Accounting-Realtime-Required value [Base] would result in a failure to establish the session. 2.2. Diameter Session Reauthentication or Reauthorization The Diameter base protocol allows for users to be periodically reauthenticated and/or reauthorized. In such instances, the Session- Id AVP in the AAR message MUST be the same as the one present in the original authentication/authorization message. A Diameter server informs the NAS of the maximum time allowed before reauthentication or reauthorization via the Authorization-Lifetime AVP [Base]. A NAS MUST reauthenticate and/or reauthorize after the period provided by the Authorization-Lifetime AVP. Calhoun et al. Expires Apr 2004 [Page 8] INTERNET-DRAFT Diameter NAS Application Oct 2003 Furthermore, it is possible for Diameter servers to issue an unsolicited reauthentication and/or reauthorization requests (e.g. Re-Auth-Request (RAR) message) to the NAS. Upon receipt of such a message, the NAS MUST respond to the request with a Re-Auth-Answer (RAA) message. If the Re-Auth-Request-Type is AUTHORIZE_ONLY, the message will contain AVPs to modify the current service. If the Re- Auth-Request-Type is AUTHORIZE_AUTHENTICATE, the NAS will reauthenticate the client, and send a new AAR message using the existing Session-Id. If accounting is active, every change of authentication or authorization MUST generate an Accounting-Record-Type of INTERIM_RECORD indicating the new session attributes and cumulative status. 2.3. Diameter Session Termination When a NAS receives an indication that a user's session is being disconnected (e.g. LCP Terminate is received), the NAS MUST issue a Session-Termination-Request (STR) [Base] to its Diameter Server. This will ensure that any resources maintained on the servers is freed appropriately. Further, a NAS that receives a Abort-Session-Request (ASR) [Base] MUST issue an STR if the session requested is active, and disconnect the PPP (or tunneling) session. Termination of the session context MUST cause the sending of an Accounting STOP_RECORD message [Base], if accounting is active. More information on Diameter Session Termination is in [Base] section 8.4. 3. NAS Messages This section defines new Diameter message Command-Code [Base] values that MUST be supported by all Diameter implementations that conform to this specification. The Command Codes are: Command-Name Abbrev. Code Reference -------------------------------------------------------- AA-Request AAR 265 3.1 AA-Answer AAA 265 3.2 Calhoun et al. Expires Apr 2004 [Page 9] INTERNET-DRAFT Diameter NAS Application Oct 2003 3.1. AA-Request (AAR) Command The AA-Request message (AAR), indicated by the Command-Code field set to 265 and the 'R' bit set in the Command Flags field, is used in order to request authentication and/or authorization for a given NAS user. The type of request is identified through the Auth-Request-Type AVP [Base]. The recommended value for most RADIUS interoperabily situations, is AUTHORIZE_AUTHENTICATE. If Authentication is requested the User-Name attribute SHOULD be present, as well as any additional authentication AVPs that would carry the password information. A request for authorization only SHOULD include the information from which the authorization will be performed, such as the User-Name, Called-Station-Id, or Calling- Station-Id AVPs. All requests SHOULD contain AVPs uniquely identifying the source of the call, such as Origin-Host, and NAS- Port. Certain networks MAY use different AVPs for authorization purposes. A request for authorization will include some AVPs defined in section 6. It is possible for a single session to be authorized first, then followed by an authentication request. This AA-Request message MAY be the result of a multi-round authentication exchange, which occurs when the AA-Answer message is received with the Result-Code AVP set to DIAMETER_MULTI_ROUND_AUTH. A subsequent AAR message SHOULD be sent, with the User-Password AVP that includes the user's response to the prompt, and MUST include any State AVPs that were present in the AAA message. Message Format ::= < Diameter Header: 265, REQ, PXY > < Session-Id > { Auth-Application-Id } { Origin-Host } { Origin-Realm } { Destination-Realm } { Auth-Request-Type } [ NAS-Port ] [ NAS-Port-Id ] [ Origin-State-Id ] [ Destination-Host ] [ NAS-Identifier ] [ NAS-IP-Address ] [ NAS-IPv6-Address ] [ NAS-Port-Type ] [ Port-Limit ] Calhoun et al. Expires Apr 2004 [Page 10] INTERNET-DRAFT Diameter NAS Application Oct 2003 [ User-Name ] [ User-Password ] [ Service-Type ] [ State ] [ Authorization-Lifetime ] [ Auth-Grace-Period ] [ Auth-Session-State ] [ Callback-Number ] [ Called-Station-Id ] [ Calling-Station-Id ] [ Originating-Line-Info ] [ Connect-Info ] [ CHAP-Auth ] [ CHAP-Challenge ] * [ Framed-Compression ] [ Framed-Interface-Id ] [ Framed-IP-Address ] * [ Framed-IPv6-Prefix ] [ Framed-IP-Netmask ] [ Framed-MTU ] [ Framed-Protocol ] [ ARAP-Password ] [ ARAP-Security ] * [ ARAP-Security-Data ] * [ Login-IP-Host ] * [ Login-IPv6-Host ] [ Login-LAT-Group ] [ Login-LAT-Node ] [ Login-LAT-Port ] [ Login-LAT-Service ] * [ Tunneling ] * [ Proxy-Info ] * [ Route-Record ] * [ AVP ] 3.2. AA-Answer (AAA) Command The AA-Answer (AAA) message, is indicated by the Command-Code field set to 265 and the 'R' bit cleared in the Command Flags field, is sent in response to the AA-Request message. If authorization was requested, a successful response will include the authorization AVPs appropriate for the service being provided, as defined in section 6. For authentication exchanges that require more than a single round trip, the server MUST set the Result-Code AVP to DIAMETER_MULTI_ROUND_AUTH. An AAA message with this result code MAY include one or more Reply-Message and MAY include zero or one State Calhoun et al. Expires Apr 2004 [Page 11] INTERNET-DRAFT Diameter NAS Application Oct 2003 AVPs. If the Reply-Message AVP was present, the network access server SHOULD send the text to the user's client for display to the user, instructing it to prompt the user for a response. For example, this capability can be achieved in PPP via PAP. If the access client is unable to prompt the user for a new response, it MUST treat the AA- Answer with the Reply-Message AVP as an error, and deny access. Message Format ::= < Diameter Header: 265, PXY > < Session-Id > { Auth-Application-Id } { Auth-Request-Type } { Result-Code } { Origin-Host } { Origin-Realm } [ User-Name ] [ Service-Type ] * [ Class ] * [ Configuration-Token ] [ Acct-Interim-Interval ] [ Error-Message ] [ Error-Reporting-Host ] [ Idle-Timeout ] [ Authorization-Lifetime ] [ Auth-Grace-Period ] [ Auth-Session-State ] [ Re-Auth-Request-Type ] [ Session-Timeout ] [ State ] * [ Reply-Message ] [ Origin-State-Id ] * [ Filter-Id ] [ Password-Retry ] [ Port-Limit ] [ Prompt ] [ ARAP-Challenge-Response ] [ ARAP-Features ] [ ARAP-Security ] * [ ARAP-Security-Data ] [ ARAP-Zone-Access ] [ Callback-Id ] [ Callback-Number ] [ Framed-Appletalk-Link ] * [ Framed-Appletalk-Network ] [ Framed-Appletalk-Zone ] Calhoun et al. Expires Apr 2004 [Page 12] INTERNET-DRAFT Diameter NAS Application Oct 2003 * [ Framed-Compression ] [ Framed-Interface-Id ] [ Framed-IP-Address ] * [ Framed-IPv6-Prefix ] [ Framed-IPv6-Pool ] * [ Framed-IPv6-Route ] [ Framed-IP-Netmask ] * [ Framed-Route ] [ Framed-Pool ] [ Framed-IPX-Network ] [ Framed-MTU ] [ Framed-Protocol ] [ Framed-Routing ] * [ Login-IP-Host ] * [ Login-IPv6-Host ] [ Login-LAT-Group ] [ Login-LAT-Node ] [ Login-LAT-Port ] [ Login-LAT-Service ] [ Login-Service ] [ Login-TCP-Port ] * [ NAS-Filter-Rule ] * [ Tunneling ] * [ Redirect-Host ] [ Redirect-Host-Usage ] [ Redirect-Max-Cache-Time ] * [ Proxy-Info ] * [ AVP ] 4. NAS Session AVPs Diameter reserves the AVP Codes 0-255 for RADIUS functions that are implemented in Diameter. AVPs new to Diameter have code values 256 and greater. A Diameter message that includes one of these AVPs may represent functions not present in the RADIUS environment and may cause interoperability issues should the request traverse a AAA system that only supports the RADIUS protocol. There are some RADIUS attributes that are not allowed or supported directly in Diameter. See section 9 below for more information. Calhoun et al. Expires Apr 2004 [Page 13] INTERNET-DRAFT Diameter NAS Application Oct 2003 4.1. Call and Session Information This section contains the AVPs specific to NAS Diameter applications that are needed to identify the call and session context and status information. On a request, this information allows the server to qualify the session. These AVPs are used in addition to the Base AVPs of: Session-Id Auth-Application-Id Origin-Host Origin-Realm Auth-Request-Type The following table describes the Session level AVPs, their AVP Code values, types, possible flag values and whether the AVP MAY be encrypted. +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST| | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| NAS-Port 5 4.2 Unsigned32 | M | P | | V | Y | NAS-Port-Id 87 4.3 UTF8String | M | P | | V | Y | NAS-Port-Type 61 4.4 Enumerated | M | P | | V | Y | Called-Station-Id 30 4.5 UTF8String | M | P | | V | Y | Calling-Station- 31 4.6 UTF8String | M | P | | V | Y | Id | | | | | | Connect-Info 77 4.7 UTF8String | M | P | | V | Y | Originating-Line- 94 4.8 OctetString| | M,P | | V | Y | Info | | | | | | Reply-Message 18 4.9 UTF8String | M | P | | V | Y | Termination- 29 4.10 Enumerated | M | P | | V | Y | Action | | | | | | -----------------------------------------|----+-----+----+-----|----| 4.2. NAS-Port AVP The NAS-Port AVP (AVP Code 5) is of type Unsigned32 and contains the physical or virtual port number of the NAS which is authenticating the user. Note that this is using "port" in its sense of a service connection on the NAS, not in the sense of an IP protocol identifier. Either NAS-Port or NAS-Port-Id (AVP Code 87) SHOULD be present in AA- Request commands if the NAS differentiates among its ports. Calhoun et al. Expires Apr 2004 [Page 14] INTERNET-DRAFT Diameter NAS Application Oct 2003 4.3. NAS-Port-Id AVP The NAS-Port-Id AVP (AVP Code 87) is of type UTF8String and consists of ASCII text that identifies the port of the NAS which is authenticating the user. Note that this is using "port" in its sense of a service connection on the NAS, not in the sense of an IP protocol identifier. Either NAS-Port or NAS-Port-Id SHOULD be present in AA-Request commands if the NAS differentiates among its ports. NAS-Port-Id is intended for use by NASes which cannot conveniently number their ports. 4.4. NAS-Port-Type AVP The NAS-Port-Type AVP (AVP Code 61) is of type Enumerated and contains the type of the port on which the NAS is authenticating the user. This AVP SHOULD be present if the NAS uses the same NAS-Port number ranges for different service types concurrently. The supported values are defined in [RADIUSTypes]. The following list is informational: 0 Async 1 Sync 2 ISDN Sync 3 ISDN Async V.120 4 ISDN Async V.110 5 Virtual 6 PIAFS 7 HDLC Clear Channel 8 X.25 9 X.75 10 G.3 Fax 11 SDSL - Symmetric DSL 12 ADSL-CAP - Asymmetric DSL, Carrierless Amplitude Phase Modulation 13 ADSL-DMT - Asymmetric DSL, Discrete Multi-Tone 14 IDSL - ISDN Digital Subscriber Line 15 Ethernet 16 xDSL - Digital Subscriber Line of unknown type 17 Cable 18 Wireless - Other 19 Wireless - IEEE 802.11 20 Token-Ring [RAD802.1X] 21 FDDI [RAD802.1X] Calhoun et al. Expires Apr 2004 [Page 15] INTERNET-DRAFT Diameter NAS Application Oct 2003 22 Wireless - CDMA2000 23 Wireless - UMTS 24 Wireless - 1X-EV 25 IAPP [IEEE 802.11f] 4.5. Called-Station-Id AVP The Called-Station-Id AVP (AVP Code 30) is of type UTF8String, and allows the NAS to send in the request, the ASCII string describing the layer 2 address that the user contacted to. For dialup access, this can be a phone number, obtained using Dialed Number Identification (DNIS) or a similar technology. Note that this may be different from the phone number the call comes in on. For use with IEEE 802 access, the Called- Station-Id MAY contain a MAC address, formatted as described in [RAD802.1X]. It SHOULD only be present in authentication and/or authorization requests. If the Auth-Request-Type AVP is set to authorization-only and the User- Name AVP is absent, the Diameter Server MAY perform authorization based on this field. This can be used by a NAS to request whether a call should be answered based on the DNIS. The codification of the range of allowed usage of this field is outside the scope of this specification. 4.6. Calling-Station-Id AVP The Calling-Station-Id AVP (AVP Code 31) is of type UTF8String, and allows the NAS to send in the request the ASCII string describing the layer 2 address that the user connected from. For dialup access, this is the phone number that the call came from, using Automatic Number Identification (ANI) or a similar technology. For use with IEEE 802 access, the Calling-Station-Id AVP MAY contain a MAC address, formated as described in [RAD802.1X]. It SHOULD only be present in authentication and/or authorization requests. If the Auth-Request-Type AVP is set to authorization-only and the User-Name AVP is absent, the Diameter Server MAY perform authorization based on this field. This can be used by a NAS to request whether a call should be answered based on the layer 2 address (ANI, MAC Address, etc.) The codification of the range of allowed usage of this field is outside the scope of this specification. Calhoun et al. Expires Apr 2004 [Page 16] INTERNET-DRAFT Diameter NAS Application Oct 2003 4.7. Connect-Info AVP The Connect-Info AVP (AVP Code 77) is of type UTF8String and is sent in the AA-Request message or ACR STOP message. When sent in the Access-Request it indicates the nature of the user's connection. The connection speed SHOULD be included at the beginning of the first Connect-Info AVP in the message. If the transmit and receive connection speeds differ, they may both be included in the first AVP with the transmit speed first (the speed the NAS modem transmits at), a slash (/), the receive speed, then optionally other information. For example, "28800 V42BIS/LAPM" or "52000/31200 V90" More than one Connect-Info attribute may be present in an Accounting- Request packet to accommodate expected efforts by ITU to have modems report more connection information in a standard format that might exceed 252 octets. If sent in the ACR STOP, this attribute may be used to summarize statistics relating to session quality. For example, in IEEE 802.11, the Connect-Info attribute may contain information on the number of link layer retransmissions. The exact format of this attribute is implementation specific. 4.8. Originating-Line-Info AVP The Originating-Line-Info AVP (AVP Code 94) is of type OctetString and is sent by the NAS system to convey information about the origin of the call from an SS7 system. The originating line information (OLI) information element indicates the nature and/or characteristics of the line from which a call originated (e.g. payphone, hotel, cellular). Telephone companies are starting to offer OLI to their customers as an option over Primary Rate Interface (PRI). Internet Service Providers (ISPs) can use OLI in addition to Called-Station-Id and Calling-Station-Id attributes to differentiate customer calls and define different services The Value field contains two octets (00-99). ANSI T1.113 and BELLCORE 394 can be used for additional information about those values and their use. For more information on current assignment values see [ANITypes]. Value Description ------------------------------------------------------------ 00 Plain Old Telephone Service (POTS) 01 Multiparty line (more than 2) Calhoun et al. Expires Apr 2004 [Page 17] INTERNET-DRAFT Diameter NAS Application Oct 2003 02 ANI Failure 03 ANI Observed 04 ONI Observed 05 ANI Failure Observed 06 Station Level Rating 07 Special Operator Handling Required 08 InterLATA Restricted 10 Test Call 20 Automatic Identified Outward Dialing (AIOD) 23 Coin or Non-Coin 24 Toll Free Service (Non-Pay origination) 25 Toll Free Service (Pay origination) 27 Toll Free Service (Coin Control origination) 29 Prison/Inmate Service 30-32 Intercept 30 Intercept (blank) 31 Intercept (trouble) 32 Intercept (regular) 34 Telco Operator Handled Call 40-49 Unrestricted Use 52 Outward Wide Area Telecommunications Service (OUTWATS) 60 Telecommunications Relay Service (TRS)(Unrestricted) 61 Cellular/Wireless PCS (Type 1) 62 Cellular/Wireless PCS (Type 2) 63 Cellular/Wireless PCS (Roaming) 66 TRS (Hotel) 67 TRS (Restricted) 70 Pay Station, No coin control 93 Access for private virtual network service 4.9. Reply-Message AVP The Reply-Message AVP (AVP Code 18) is of type UTF8String, and contains text which MAY be displayed to the user. When used in an AA-Answer message with a successful Result-Code AVP it indicates a success message. When found in the same message with a Result-Code other than DIAMETER_SUCCESS it contains a failure message. The Reply-Message AVP MAY indicate a dialog message to prompt the user before another AA-Request attempt. When used in an AA-Answer, it MAY indicate a dialog message to prompt the user for a response. Multiple Reply-Message's MAY be included and if any are displayed, they MUST be displayed in the same order as they appear in the message. Calhoun et al. Expires Apr 2004 [Page 18] INTERNET-DRAFT Diameter NAS Application Oct 2003 5. NAS Authentication AVPs This section defines the AVPs that are necessary to carry the authentication information in the Diameter protocol. The functionality defined here provides a RADIUS-like AAA service, over a more reliable and secure transport, as defined in the base protocol [Base]. The following table describes the AVPs, their AVP Code values, types, possible flag values and whether the AVP MAY be encrypted. +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST| | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| User-Password 2 5.1 OctetString| M | P | | V | Y | Password-Retry 75 5.2 Unsigned32 | M | P | | V | Y | Prompt 76 5.3 Enumerated | M | P | | V | Y | CHAP-Auth 402 5.4 Grouped | M | P | | V | Y | CHAP-Algorithm 403 5.5 Enumerated | M | P | | V | Y | CHAP-Ident 404 5.6 OctetString| M | P | | V | Y | CHAP-Response 405 5.7 OctetString| M | P | | V | Y | CHAP-Challenge 60 5.8 OctetString| M | P | | V | Y | ARAP-Password 70 5.9 OctetString| M | P | | V | Y | ARAP-Challenge- 84 5.10 OctetString| M | P | | V | Y | Response | | | | | | ARAP-Security 73 5.11 Unsigned32 | M | P | | V | Y | ARAP-Security- 74 5.12 OctetString| M | P | | V | Y | Data | | | | | | -----------------------------------------|----+-----+----+-----|----| 5.1. User-Password AVP The User-Password AVP (AVP Code 2) is of type OctetString and contains the password of the user to be authenticated, or the user's input in a multi-round authentication exchange. The User-Password AVP contains a user password or one-time password and therefore represents sensitive information. As required in [Base], Diameter messages are encrypted using IPsec or TLS. Unless this AVP is used for one-time passwords, the User-Password AVP SHOULD NOT be used in untrusted proxy environments without encrypting it using end-to-end security techniques, such as CMS Security [DiamCMS]. The clear-text password (prior to encryption) MUST NOT be longer than Calhoun et al. Expires Apr 2004 [Page 19] INTERNET-DRAFT Diameter NAS Application Oct 2003 128 bytes in length. 5.2. Password-Retry AVP The Password-Retry AVP (AVP Code 75) is of type Unsigned32 and MAY be included in the AA-Answer if the Result-Code indicates an authentication failure. The value of this AVP indicates how many authentication attempts a user may be permitted before being disconnected. This AVP is primarily intended for use when the Framed- Protocol AVP (see Section 6.9.1) is set to ARAP. 5.3. Prompt AVP The Prompt AVP (AVP Code 76) is of type Enumerated, and MAY be present in the AA-Answer message. When present, it is used by the NAS to determine whether the user's response, when entered, should be echoed. The supported values are listed in [RADIUSTypes]. The following list is informational: 0 No Echo 1 Echo 5.4. CHAP-Auth AVP The CHAP-Auth AVP (AVP Code 402) is of type Grouped and contains the information necessary to authenticate a user using the PPP Challenge- Handshake Authentication Protocol (CHAP) [PPPCHAP]. If the CHAP-Auth AVP is found in a message, the CHAP-Challenge AVP MUST be present as well. The optional AVPs containing the CHAP response depend upon the value of the CHAP-Algorithm AVP. The grouped AVP has the following ABNF grammar: CHAP-Auth ::= < AVP Header: 402 > { CHAP-Algorithm } { CHAP-Ident } [ CHAP-Response ] * [ AVP ] 5.5. CHAP-Algorithm AVP The CHAP-Algorithm AVP (AVP Code 403) is of type Enumerated and contains the algorithm identifier used in the computation of the CHAP Calhoun et al. Expires Apr 2004 [Page 20] INTERNET-DRAFT Diameter NAS Application Oct 2003 response [PPPCHAP]. The following values are currently supported: CHAP with MD5 5 The CHAP response is computed using the procedure described in [PPPCHAP]. This algorithm requires that CHAP-Response AVP MUST be present in the CHAP-Auth AVP. 5.6. CHAP-Ident AVP The CHAP-Ident AVP (AVP Code 404) is of type OctetString and contains the one octet CHAP Identifier used in the computation of the CHAP response [PPPCHAP]. 5.7. CHAP-Response AVP The CHAP-Response AVP (AVP Code 405) is of type OctetString and contains the 16 octet authentication data provided by the user in response to the CHAP challenge [PPPCHAP]. 5.8. CHAP-Challenge AVP The CHAP-Challenge AVP (AVP Code 60) is of type OctetString and contains the CHAP Challenge sent by the NAS to the CHAP peer [PPPCHAP]. 5.9. ARAP-Password AVP The ARAP-Password AVP (AVP Code 70) is of type OctetString and is only present when the Framed-Protocol AVP (see Section 6.9.1) is included in the message and is set to ARAP. This AVP MUST NOT be present if either the User-Password or the CHAP-Auth AVP is present. See [RADIUSExt] for more information on the contents of this AVP. 5.10. ARAP-Challenge-Response AVP The ARAP-Challenge-Response AVP (AVP Code 84) is of type OctetString and is only present when the Framed-Protocol AVP (see Section 6.9.1) is included in the message and is set to ARAP. This AVP contains an 8 octet response to the dial-in client's challenge. The RADIUS server calculates this value by taking the dial-in client's challenge from the high order 8 octets of the ARAP-Password AVP and performing DES encryption on this value with the authenticating user's password as the key. If the user's password is less than 8 octets in length, the Calhoun et al. Expires Apr 2004 [Page 21] INTERNET-DRAFT Diameter NAS Application Oct 2003 password is padded at the end with NULL octets to a length of 8 before using it as a key. 5.11. ARAP-Security AVP The ARAP-Security AVP (AVP Code 73) is of type Unsigned32, and MAY be present in the AA-Answer message if the Framed-Protocol AVP (see Section 6.9.1) is set to the value of ARAP, and the Result-Code AVP is set to DIAMETER_MULTI_ROUND_AUTH. See [RADIUSExt] for more information on the format of this AVP. 5.12. ARAP-Security-Data AVP The ARAP-Security AVP (AVP Code 74) is of type OctetString, and MAY be present in the AA-Request or AA-Answer message if the Framed- Protocol AVP is set to the value of ARAP, and the Result-Code AVP is set to DIAMETER_MULTI_ROUND_AUTH. This AVP contains the security module challenge or response associated with the ARAP Security Module specified in ARAP-Security. 6. NAS Authorization AVPs This section contains the authorization AVPs that are supported in the NAS Application. The Service-Type AVP SHOULD be present in all messages, and based on its value, additional AVPs defined in this section and section 7 MAY be present. Due to space constraints, the short form IPFiltrRule is used to represent IPFilterRule. +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST| | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| Service-Type 6 6.1 Enumerated | M | P | | V | Y | Callback-Number 19 6.2 UTF8String | M | P | | V | Y | Callback-Id 20 6.3 UTF8String | M | P | | V | Y | Idle-Timeout 28 6.4 Unsigned32 | M | P | | V | Y | Port-Limit 62 6.5 Unsigned32 | M | P | | V | Y | NAS-Filter-Rule 400 6.6 IPFiltrRule| M | P | | V | Y | Filter-Id 11 6.7 UTF8String | M | P | | V | Y | Configuration- 78 6.8 OctetString| M | | | P,V | | Token | | | | | | Framed-Protocol 7 6.9.1 Enumerated | M | P | | V | Y | Calhoun et al. Expires Apr 2004 [Page 22] INTERNET-DRAFT Diameter NAS Application Oct 2003 Framed-Routing 10 6.9.2 Enumerated | M | P | | V | Y | Framed-MTU 12 6.9.3 Unsigned32 | M | P | | V | Y | Framed- 13 6.9.4 Enumerated | M | P | | V | Y | Compression | | | | | | Framed-IP-Address 8 6.10.1 OctetString| M | P | | V | Y | Framed-IP-Netmask 9 6.10.2 OctetString| M | P | | V | Y | Framed-Route 22 6.10.3 UTF8String | M | P | | V | Y | Framed-Pool 88 6.10.4 OctetString| M | P | | V | Y | Framed- 96 6.10.5 Unsigned64 | M | P | | V | Y | Interface-Id | | | | | | Framed-IPv6- 97 6.10.6 OctetString| M | P | | V | Y | Prefix | | | | | | Framed-IPv6- 99 6.10.7 UTF8String | M | P | | V | Y | Route | | | | | | Framed-IPv6-Pool 100 6.10.8 OctetString| M | P | | V | Y | Framed-IPX- 23 6.11.1 UTF8String | M | P | | V | Y | Network | | | | | | Framed-Appletalk- 37 6.12.1 Unsigned32 | M | P | | V | Y | Link | | | | | | Framed-Appletalk- 38 6.12.2 Unsigned32 | M | P | | V | Y | Network | | | | | | Framed-Appletalk- 39 6.12.3 OctetString| M | P | | V | Y | Zone | | | | | | ARAP-Features 71 6.13.1 OctetString| M | P | | V | Y | ARAP-Zone-Access 72 6.13.2 Enumerated | M | P | | V | Y | Login-IP-Host 14 6.14.1 OctetString| M | P | | V | Y | Login-IPv6-Host 98 6.14.2 OctetString| M | P | | V | Y | Login-Service 15 6.14.3 Enumerated | M | P | | V | Y | Login-TCP-Port 16 6.15.1 Unsigned32 | M | P | | V | Y | Login-LAT-Service 34 6.16.1 OctetString| M | P | | V | Y | Login-LAT-Node 35 6.16.2 OctetString| M | P | | V | Y | Login-LAT-Group 36 6.16.3 OctetString| M | P | | V | Y | Login-LAT-Port 63 6.16.4 OctetString| M | P | | V | Y | -----------------------------------------|----+-----+----+-----|----| 6.1. Service-Type AVP The Service-Type AVP (AVP Code 6) is of type Enumerated and contains the type of service the user has requested, or the type of service to be provided. One such AVP MAY be present in an authentication and/or authorization request or response. A NAS is not required to implement all of these service types, and MUST treat unknown or unsupported Service-Types as a failure, and end the session with a DIAMETER_INVALID_AVP_VALUE Result-Code. When used in a request, the Service-Type AVP SHOULD be considered to be a hint to the server that the NAS has reason to believe the user Calhoun et al. Expires Apr 2004 [Page 23] INTERNET-DRAFT Diameter NAS Application Oct 2003 would prefer the kind of service indicated, but the server is not required to honor the hint. Furthermore, if the service specified by the server is supported, but not compatible with the current mode of access, the NAS MUST fail to start the session. It MUST also generate the appropriate error message(s). The following values have been defined for the Service-Type AVP. The complete list of defined values can be found in [RADIUS] and [RADIUSTypes]. The following list is informational: 1 Login 2 Framed 3 Callback Login 4 Callback Framed 5 Outbound 6 Administrative 7 NAS Prompt 8 Authenticate Only 9 Callback NAS Prompt 10 Call Check 11 Callback Administrative 12 Voice 13 Fax 14 Modem Relay 15 IAPP-Register [IEEE 802.11f] 16 IAPP-AP-Check [IEEE 802.11f] 17 Authorize Only [RFC3576] The following values are further qualified: Login 1 The user should be connected to a host. The message MAY include additional AVPs defined in sections 6.15 or 6.16. Framed 2 A Framed Protocol should be started for the User, such as PPP or SLIP. The message MAY include additional AVPs defined in sections 6.9, or 7 for tunneling services. Callback Login 3 The user should be disconnected and called back, then connected to a host. The message MAY include additional AVPs defined in this section. Callback Framed 4 The user should be disconnected and called back, then a Framed Protocol should be started for the User, such as PPP or SLIP. The message MAY include additional AVPs defined in sections 6.9, or 7 for tunneling services. Calhoun et al. Expires Apr 2004 [Page 24] INTERNET-DRAFT Diameter NAS Application Oct 2003 6.2. Callback-Number AVP The Callback-Number AVP (AVP Code 19) is of type UTF8String, and contains a dialing string to be used for callback. It MAY be used in an authentication and/or authorization request as a hint to the server that a Callback service is desired, but the server is not required to honor the hint in the corresponding response. The codification of the range of allowed usage of this field is outside the scope of this specification. 6.3. Callback-Id AVP The Callback-Id AVP (AVP Code 20) is of type UTF8String, and contains the name of a place to be called, to be interpreted by the NAS. This AVP MAY be present in an authentication and/or authorization response. This AVP is not roaming-friendly since it assumes that the Callback- Id is configured on the NAS. It is therefore preferable to use the Callback-Number AVP instead. 6.4. Idle-Timeout AVP The Idle-Timeout AVP (AVP Code 28) is of type Unsigned32 and sets the maximum number of consecutive seconds of idle connection allowed to the user before termination of the session or prompt. It MAY be used in an authentication and/or authorization request (or challenge) as a hint to the server that an idle timeout is desired, but the server is not required to honor the hint in the corresponding response. The default is none, or system specific. 6.5. Port-Limit AVP The Port-Limit AVP (AVP Code 62) is of type Unsigned32 and sets the maximum number of ports to be provided to the user by the NAS. It MAY be used in an authentication and/or authorization request as a hint to the server that multilink PPP [PPPMP] service is desired, but the server is not required to honor the hint in the corresponding response. Calhoun et al. Expires Apr 2004 [Page 25] INTERNET-DRAFT Diameter NAS Application Oct 2003 6.6. NAS-Filter-Rule AVP The NAS-Filter-Rule AVP (AVP Code 400) is of type IPFilterRule, and provides filter rules that need to be configured on the NAS for the user. One or more such AVPs MAY be present in an authorization response. 6.7. Filter-Id AVP The Filter-Id AVP (AVP Code 11) is of type UTF8String, and contains the name of the filter list for this user. Zero or more Filter-Id AVPs MAY be sent in an authorization answer. Identifying a filter list by name allows the filter to be used on different NASes without regard to filter-list implementation details. However, this AVP is not roaming friendly since filter naming differs from one service provider to another. In non-RADIUS environments, it is RECOMMENDED that the NAS-Filter- Rule AVP be used instead. 6.8. Configuration-Token AVP The Configuration-Token AVP (AVP Code 78) is of type OctetString and is sent by a Diameter Server to a Diameter Proxy Agent or Translation Agent in an AA-Answer command to indicate a type of user profile to be used. It should not be sent to a Diameter Client (NAS). The format of the Data field of this AVP is site specific. 6.9. Framed Access Authorization AVPs This section contains the authorization AVPs that are necessary to support framed access, such as PPP, SLIP, etc. AVPs defined in this section MAY be present in a message if the Service-Type AVP was set to "Framed" or "Callback Framed". 6.9.1. Framed-Protocol AVP The Framed-Protocol AVP (AVP Code 7) is of type Enumerated and contains the framing to be used for framed access. This AVP MAY be present in both requests and responses. The supported values are listed in [RADIUSTypes]. The following list is informational: Calhoun et al. Expires Apr 2004 [Page 26] INTERNET-DRAFT Diameter NAS Application Oct 2003 1 PPP 2 SLIP 3 AppleTalk Remote Access Protocol (ARAP) 4 Gandalf proprietary SingleLink/MultiLink protocol 5 Xylogics proprietary IPX/SLIP 6 X.75 Synchronous 6.9.2. Framed-Routing AVP The Framed-Routing AVP (AVP Code 10) is of type Enumerated and contains the routing method for the user, when the user is a router to a network. This AVP SHOULD only be present in authorization responses. The supported values are listed in [RADIUSTypes]. The following list is informational: 0 None 1 Send routing packets 2 Listen for routing packets 3 Send and Listen 6.9.3. Framed-MTU AVP The Framed-MTU AVP (AVP Code 12) is of type Unsigned32 and contains the Maximum Transmission Unit to be configured for the user, when it is not negotiated by some other means (such as PPP). This AVP SHOULD only be present in authorization responses. The MTU value MUST be in the range of 64 and 65535. 6.9.4. Framed-Compression AVP The Framed-Compression AVP (AVP Code 13) is of type Enumerated and contains the compression protocol to be used for the link. It MAY be used in an authorization request as a hint to the server that a specific compression type is desired, but the server is not required to honor the hint in the corresponding response. More than one compression protocol AVP MAY be sent. It is the responsibility of the NAS to apply the proper compression protocol to appropriate link traffic. The supported values are listed in [RADIUSTypes]. The following list is informational: 0 None Calhoun et al. Expires Apr 2004 [Page 27] INTERNET-DRAFT Diameter NAS Application Oct 2003 1 VJ TCP/IP header compression 2 IPX header compression 3 Stac-LZS compression 6.10. IP Access The AVPs defined in this section are used when the user requests, or is being granted, access to IP. They are only present if the Framed- Protocol AVP (see Section 6.9.1) is set to PPP, SLIP, Gandalf proprietary SingleLink/MultiLink protocol, or X.75 Synchronous. 6.10.1. Framed-IP-Address AVP The Framed-IP-Address AVP (AVP Code 8) [RADIUS] is of type OctetString and contains an IPv4 address, of the type specified in the attribute value, to be configured for the user. It MAY be used in an authorization request as a hint to the server that a specific address is desired, but the server is not required to honor the hint in the corresponding response. Two IPv4 addresses have special significance; 0xFFFFFFFF and 0xFFFFFFFE. The value 0xFFFFFFFF indicates that the NAS should allow the user to select an address (e.g. Negotiated). The value 0xFFFFFFFE indicates that the NAS should select an address for the user (e.g. Assigned from a pool of addresses kept by the NAS). 6.10.2. Framed-IP-Netmask AVP The Framed-IP-Netmask AVP (AVP Code 9) is of type OctetString and contains the four octets of the IPv4 netmask to be configured for the user when the user is a router to a network. It MAY be used in an authorization request as a hint to the server that a specific netmask is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST be present in a response if the request included this AVP with a value of 0xFFFFFFFF. 6.10.3. Framed-Route AVP The Framed-Route AVP (AVP Code 22) is of type UTF8String, and contains the ASCII routing information to be configured for the user on the NAS. Zero or more such AVPs MAY be present in an authorization response. The string MUST contain a destination prefix in dotted quad form Calhoun et al. Expires Apr 2004 [Page 28] INTERNET-DRAFT Diameter NAS Application Oct 2003 optionally followed by a slash and a decimal length specifier stating how many high order bits of the prefix should be used. That is followed by a space, a gateway address in dotted quad form, a space, and one or more metrics separated by spaces. For example, "192.168.1.0/24 192.168.1.1 1". The length specifier may be omitted in which case it should default to 8 bits for class A prefixes, 16 bits for class B prefixes, and 24 bits for class C prefixes. For example, "192.168.1.0 192.168.1.1 1". Whenever the gateway address is specified as "0.0.0.0" the IP address of the user SHOULD be used as the gateway address. 6.10.4. Framed-Pool AVP The Framed-Pool AVP (AVP Code 88) is of type OctetString and contains the name of an assigned address pool that SHOULD be used to assign an address for the user. If a NAS does not support multiple address pools, the NAS SHOULD ignore this AVP. Address pools are usually used for IP addresses, but can be used for other protocols if the NAS supports pools for those protocols. Although specified as type OctetString for compatibility with RADIUS [RADIUSExt], the encoding of the Data field SHOULD also conform to the rules for the UTF8String Data Format. 6.10.5. Framed-Interface-Id AVP The Framed-Interface-Id AVP (AVP Code 96) is of type Unsigned64 and contains the IPv6 interface identifier to be configured for the user. It MAY be used in authorization requests as a hint to the server that a specific interface id is desired, but the server is not required to honor the hint in the corresponding response. 6.10.6. Framed-IPv6-Prefix AVP The Framed-IPv6-Prefix AVP (AVP Code 97) is of type OctetString and contains the IPv6 prefix to be configured for the user. One or more AVPs MAY be used in authorization requests as a hint to the server that a specific IPv6 prefixes are desired, but the server is not required to honor the hint in the corresponding response. Calhoun et al. Expires Apr 2004 [Page 29] INTERNET-DRAFT Diameter NAS Application Oct 2003 6.10.7. Framed-IPv6-Route AVP The Framed-IPv6-Route AVP (AVP Code 99) is of type UTF8String, and contains the ASCII routing information to be configured for the user on the NAS. Zero or more such AVPs MAY be present in an authorization response. The string MUST contain an IPv6 address prefix followed by a slash and a decimal length specifier stating how many high order bits of the prefix should be used. That is followed by a space, a gateway address in hexadecimal notation, a space, and one or more metrics separated by spaces. For example: "2000:0:0:106::/64 2000::106:a00:20ff:fe99:a998 1". Whenever the gateway address is the IPv6 unspecified address the IP address of the user SHOULD be used as the gateway address, such as: "2000:0:0:106::/64 :: 1". 6.10.8. Framed-IPv6-Pool AVP The Framed-IPv6-Pool AVP (AVP Code 100) is of type OctetString, and contains the name of an assigned pool that SHOULD be used to assign an IPv6 prefix for the user. If the access device does not support multiple prefix pools, it MUST ignore this AVP. Although specified as type OctetString for compatibility with RADIUS [RADIUSIPv6], the encoding of the Data field SHOULD also conform to the rules for the UTF8String Data Format. 6.11. IPX Access The AVPs defined in this section are used when the user requests, or is being granted, access to IPX. They are only present if the Framed- Protocol AVP (see Section 6.9.1) is set to PPP, Xylogics proprietary IPX/SLIP, Gandalf proprietary SingleLink/MultiLink protocol, or X.75 Synchronous. 6.11.1. Framed-IPX-Network AVP The Framed-IPX-Network AVP (AVP Code 23) is of type Unsigned32, and contains the IPX Network number to be configured for the user. It MAY be used in an authorization request as a hint to the server that a specific address is desired, but the server is not required to honor the hint in the corresponding response. Calhoun et al. Expires Apr 2004 [Page 30] INTERNET-DRAFT Diameter NAS Application Oct 2003 Two addresses have special significance; 0xFFFFFFFF and 0xFFFFFFFE. The value 0xFFFFFFFF indicates that the NAS should allow the user to select an address (e.g. Negotiated). The value 0xFFFFFFFE indicates that the NAS should select an address for the user (e.g. assigned from a pool of one or more IPX networks kept by the NAS). 6.12. Appletalk Access The AVPs defined in this section are used when the user requests, or is being granted, access to Appletalk. They are only present if the Framed-Protocol AVP (see Section 6.9.1) is set to PPP, Gandalf proprietary SingleLink/MultiLink protocol, or X.75 Synchronous. 6.12.1. Framed-AppleTalk-Link AVP The Framed-AppleTalk-Link AVP (AVP Code 37) is of type Unsigned32 and contains the AppleTalk network number which should be used for the serial link to the user, which is another AppleTalk router. This AVP MUST only be present in an authorization response and is never used when the user is not another router. Despite the size of the field, values range from zero to 65535. The special value of zero indicates that this is an unnumbered serial link. A value of one to 65535 means that the serial line between the NAS and the user should be assigned that value as an AppleTalk network number. 6.12.2. Framed-AppleTalk-Network AVP The Framed-AppleTalk-Network AVP (AVP Code 38) is of type Unsigned32 and contains the AppleTalk Network number which the NAS should probe to allocate an AppleTalk node for the user. This AVP MUST only be present in an authorization response and is never used when the user is not another router. Multiple instances of this AVP indicate that the NAS may probe using any of the network numbers specified. Despite the size of the field, values range from zero to 65535. The special value zero indicates that the NAS should assign a network for the user, using its default cable range. A value between one and 65535 (inclusive) indicates the AppleTalk Network the NAS should probe to find an address for the user. Calhoun et al. Expires Apr 2004 [Page 31] INTERNET-DRAFT Diameter NAS Application Oct 2003 6.12.3. Framed-AppleTalk-Zone AVP The Framed-AppleTalk-Zone AVP (AVP Code 39) is of type OctetString and contains the AppleTalk Default Zone to be used for this user. This AVP MUST only be present in an authorization response. Multiple instances of this AVP in the same message are not allowed. The codification of the range of allowed usage of this field is outside the scope of this specification. 6.13. ARAP Access The AVPs defined in this section are used when the user requests, or is being granted, access to ARAP. They are only present if the Framed-Protocol AVP (see Section 6.9.1) is set to AppleTalk Remote Access Protocol (ARAP). 6.13.1. ARAP-Features AVP The ARAP-Features AVP (AVP Code 71) is of type OctetString, and MAY be present in the AA-Accept message if the Framed-Protocol AVP is set to the value of ARAP. See [RADIUSExt] for more information of the format of this AVP. 6.13.2. ARAP-Zone-Access AVP The ARAP-Zone-Access AVP (AVP Code 72) is of type Enumerated, and MAY be present in the AA-Accept message if the Framed-Protocol AVP is set to the value of ARAP. The supported values are listed in [RADIUSTypes], and are defined in [RADIUSExt]. 6.14. Non-Framed Access Authorization AVPs This section contains the authorization AVPs that are needed to support terminal server functionality. AVPs defined in this section MAY be present in a message if the Service-Type AVP was set to "Login" or "Callback Login". Calhoun et al. Expires Apr 2004 [Page 32] INTERNET-DRAFT Diameter NAS Application Oct 2003 6.14.1. Login-IP-Host AVP The Login-IP-Host AVP (AVP Code 14) [RADIUS] is of type OctetString and contains the IPv4 address of a host with which to connect the user when the Login-Service AVP is included. It MAY be used in an AA-Request command as a hint to the Diameter Server that a specific host is desired, but the Diameter Server is not required to honor the hint in the AA-Answer. Two addresses have special significance: All ones and 0. The value of all ones indicates that the NAS SHOULD allow the user to select an address. The value 0 indicates that the NAS SHOULD select a host to connect the user to. 6.14.2. Login-IPv6-Host AVP The Login-IPv6-Host AVP (AVP Code 98) [RADIUSIPv6] is of type OctetString and contains the IPv6 address of a host with which to connect the user when the Login-Service AVP is included. It MAY be used in an AA-Request command as a hint to the Diameter Server that a specific host is desired, but the Diameter Server is not required to honor the hint in the AA-Answer. Two addresses have special significance: 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF and 0. The value 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF indicates that the NAS SHOULD allow the user to select an address. The value 0 indicates that the NAS SHOULD select a host to connect the user to. 6.14.3. Login-Service AVP The Login-Service AVP (AVP Code 15) is of type Enumerated and contains the service which should be used to connect the user to the login host. This AVP SHOULD only be present in authorization responses. The supported values are listed in [RADIUSTypes]. The following list is informational: 0 Telnet 1 Rlogin 2 TCP Clear 3 PortMaster (proprietary) 4 LAT 5 X25-PAD 6 X25-T3POS Calhoun et al. Expires Apr 2004 [Page 33] INTERNET-DRAFT Diameter NAS Application Oct 2003 8 TCP Clear Quiet (suppresses any NAS-generated connect string) 6.15. TCP Services The AVPs described in this section MAY be present if the Login- Service AVP is set to Telnet, Rlogin, TCP Clear or TCP Clear Quiet. 6.15.1. Login-TCP-Port AVP The Login-TCP-Port AVP (AVP Code 16) is of type Unsigned32 and contains the TCP port with which the user is to be connected, when the Login-Service AVP is also present. This AVP SHOULD only be present in authorization responses. The value MUST NOT be greater than 65535. 6.15.2. LAT Services The AVP described in this section MAY be present if the Login-Service AVP is set to LAT. 6.15.3. Login-LAT-Service AVP The Login-LAT-Service AVP (AVP Code 34) is of type OctetString and contains the system with which the user is to be connected by LAT. It MAY be used in an authorization request as a hint to the server that a specific service is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST only be present in the response if the Login-Service AVP states that LAT is desired. Administrators use the service attribute when dealing with clustered systems, such as a VAX or Alpha cluster. In such an environment several different time sharing hosts share the same resources (disks, printers, etc.), and administrators often configure each to offer access (service) to each of the shared resources. In this case, each host in the cluster advertises its services through LAT broadcasts. Sophisticated users often know which service providers (machines) are faster and tend to use a node name when initiating a LAT connection. Alternately, some administrators want particular users to use certain machines as a primitive form of load balancing (although LAT knows how to do load balancing itself). Calhoun et al. Expires Apr 2004 [Page 34] INTERNET-DRAFT Diameter NAS Application Oct 2003 The String field contains the identity of the LAT service to use. The LAT Architecture allows this string to contain $ (dollar), - (hyphen), . (period), _ (underscore), numerics, upper and lower case alphabetics, and the ISO Latin-1 character set extension [ISOLatin]. All LAT string comparisons are case insensitive. 6.15.4. Login-LAT-Node AVP The Login-LAT-Node AVP (AVP Code 35) is of type OctetString and contains the Node with which the user is to be automatically connected by LAT. It MAY be used in an authorization request as a hint to the server that a specific LAT node is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST only be present in a response if the Service- Type AVP is set to LAT. The String field contains the identity of the LAT service to use. The LAT Architecture allows this string to contain $ (dollar), - (hyphen), . (period), _ (underscore), numerics, upper and lower case alphabetics, and the ISO Latin-1 character set extension [ISOLatin]. All LAT string comparisons are case insensitive. 6.15.5. Login-LAT-Group AVP The Login-LAT-Group AVP (AVP Code 36) is of type OctetString and contains a string identifying the LAT group codes which this user is authorized to use. It MAY be used in an authorization request as a hint to the server that a specific group is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST only be present in a response if the Service-Type AVP is set to LAT. LAT supports 256 different group codes, which LAT uses as a form of access rights. LAT encodes the group codes as a 256 bit bitmap. Administrators can assign one or more of the group code bits at the LAT service provider; it will only accept LAT connections that have these group codes set in the bit map. The administrators assign a bitmap of authorized group codes to each user; LAT gets these from the operating system, and uses these in its requests to the service providers. The codification of the range of allowed usage of this field is outside the scope of this specification. Calhoun et al. Expires Apr 2004 [Page 35] INTERNET-DRAFT Diameter NAS Application Oct 2003 6.15.6. Login-LAT-Port AVP The Login-LAT-Port AVP (AVP Code 63) is of type OctetString and contains the Port with which the user is to be connected by LAT. It MAY be used in an authorization request as a hint to the server that a specific port is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST only be present in a response if the Service-Type AVP is set to LAT. The String field contains the identity of the LAT service to use. The LAT Architecture allows this string to contain $ (dollar), - (hyphen), . (period), _ (underscore), numerics, upper and lower case alphabetics, and the ISO Latin-1 character set extension [ISOLatin]. All LAT string comparisons are case insensitive. 7. NAS Tunneling Some NASes support compulsory tunnel services where the incoming connection data is conveyed by a encapsulation method to a gateway elsewhere in the network. This is typically transparent to the service user, and the tunnel characteristics may be described by the remote AAA server, based on the user's authorization information. Several tunnel characteristics may be returned, and the NAS implementation may choose one. [RADTunnels],[RADTunlAcct] Calhoun et al. Expires Apr 2004 [Page 36] INTERNET-DRAFT Diameter NAS Application Oct 2003 +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST| | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT |Encr| -----------------------------------------|----+-----+----+-----|----| Tunneling 401 7.1 Grouped | M | P | | V | N | Tunnel-Type 64 7.2 Enumerated | M | P | | V | Y | Tunnel-Medium- 65 7.3 Enumerated | M | P | | V | Y | Type | | | | | | Tunnel-Client- 66 7.4 UTF8String | M | P | | V | Y | Endpoint | | | | | | Tunnel-Server- 67 7.5 UTF8String | M | P | | V | Y | Endpoint | | | | | | Tunnel-Password 69 7.6 OctetString| M | P | | V | Y | Tunnel-Private- 81 7.7 UTF8String | M | P | | V | Y | Group-Id | | | | | | Tunnel- 82 7.8 OctetString| M | P | | V | Y | Assignment-Id | | | | | | Tunnel-Preference 83 7.9 Unsigned32 | M | P | | V | Y | Tunnel-Client- 90 7.10 Unsigned32 | M | P | | V | Y | Auth-Id | | | | | | Tunnel-Server- 91 7.11 OctetString| M | P | | V | Y | Auth-Id | | | | | | -----------------------------------------|----+-----+----+-----|----| 7.1. Tunneling AVP The Tunneling AVP (AVP Code 401) is of type Grouped and contains the following AVPs used to describe a compulsory tunnel service [RADTunnels],[RADTunlAcct]. Its data field has the following ABNF grammar: Tunneling ::= < AVP Header: 401 > { Tunnel-Type } { Tunnel-Medium-Type } { Tunnel-Client-Endpoint } { Tunnel-Server-Endpoint } [ Tunnel-Preference ] [ Tunnel-Client-Auth-Id ] [ Tunnel-Server-Auth-Id ] [ Tunnel-Assignment-Id ] [ Tunnel-Password ] [ Tunnel-Private-Group-Id ] Calhoun et al. Expires Apr 2004 [Page 37] INTERNET-DRAFT Diameter NAS Application Oct 2003 7.2. Tunnel-Type AVP The Tunnel-Type AVP (AVP Code 64) is of type Enumerated and contains the tunneling protocol(s) to be used (in the case of a tunnel initiator) or the tunneling protocol in use (in the case of a tunnel terminator). It MAY be used in an authorization request as a hint to the server that a specific tunnel type is desired, but the server is not required to honor the hint in the corresponding response. The Tunnel-Type AVP SHOULD also be included in Accounting-Request messages. A tunnel initiator is not required to implement any of these tunnel types; if a tunnel initiator receives a response that contains only unknown or unsupported Tunnel-Types, the tunnel initiator MUST behave as though a response was received with the Result-Code indicating a failure. The supported values are listed in [RADIUSTypes]. The following list is informational: 1 Point-to-Point Tunneling Protocol (PPTP) 2 Layer Two Forwarding (L2F) 3 Layer Two Tunneling Protocol (L2TP) 4 Ascend Tunnel Management Protocol (ATMP) 5 Virtual Tunneling Protocol (VTP) 6 IP Authentication Header in the Tunnel-mode (AH) 7 IP-in-IP Encapsulation (IP-IP) 8 Minimal IP-in-IP Encapsulation (MIN-IP-IP) 9 IP Encapsulating Security Payload in the Tunnel-mode (ESP) 10 Generic Route Encapsulation (GRE) 11 Bay Dial Virtual Services (DVS) 12 IP-in-IP Tunneling 13 Virtual LANs (VLAN) 7.3. Tunnel-Medium-Type AVP The Tunnel-Medium-Type AVP (AVP Code 65) is of type Enumerated and contains the transport medium to use when creating a tunnel for those protocols (such as L2TP) that can operate over multiple transports. It MAY be used in an authorization request as a hint to the server that a specific medium is desired, but the server is not required to honor the hint in the corresponding response. The supported values are listed in [RADIUSTypes]. The following list is informational: Calhoun et al. Expires Apr 2004 [Page 38] INTERNET-DRAFT Diameter NAS Application Oct 2003 1 IPv4 (IP version 4) 2 IPv6 (IP version 6) 3 NSAP 4 HDLC (8-bit multidrop) 5 BBN 1822 6 802 (includes all 802 media plus Ethernet "canonical format") 7 E.163 (POTS) 8 E.164 (SMDS, Frame Relay, ATM) 9 F.69 (Telex) 10 X.121 (X.25, Frame Relay) 11 IPX 12 Appletalk 13 Decnet IV 14 Banyan Vines 15 E.164 with NSAP format subaddress 7.4. Tunnel-Client-Endpoint AVP The Tunnel-Client-Endpoint AVP (AVP Code 66) is of type UTF8String, and contains the address of the initiator end of the tunnel. It MAY be used in an authorization request as a hint to the server that a specific endpoint is desired, but the server is not required to honor the hint in the corresponding response. This AVP SHOULD be included in the corresponding Accounting-Request messages, in which case it indicates the address from which the tunnel was initiated. This AVP, along with the Tunnel-Server-Endpoint and Session-Id AVP [Base], MAY be used to provide a globally unique means to identify a tunnel for accounting and auditing purposes. If Tunnel-Medium-Type is IPv4 (1), then this string is either the fully qualified domain name (FQDN) of the tunnel client machine, or it is a "dotted-decimal" IP address. Implementations MUST support the dotted-decimal format and SHOULD support the FQDN format for IP addresses. If Tunnel-Medium-Type is IPv6 (2), then this string is either the FQDN of the tunnel client machine, or it is a text representation of the address in either the preferred or alternate form [IPv6Addr]. Conformant implementations MUST support the preferred form and SHOULD support both the alternate text form and the FQDN format for IPv6 addresses. If Tunnel-Medium-Type is neither IPv4 nor IPv6, this string is a tag referring to configuration data local to the Diameter client that describes the interface and medium-specific address to use. Calhoun et al. Expires Apr 2004 [Page 39] INTERNET-DRAFT Diameter NAS Application Oct 2003 7.5. Tunnel-Server-Endpoint AVP The Tunnel-Server-Endpoint AVP (AVP Code 67) is of UTF8String, and contains the address of the server end of the tunnel. It MAY be used in an authorization request as a hint to the server that a specific endpoint is desired, but the server is not required to honor the hint in the corresponding response. This AVP SHOULD be included in the corresponding Accounting-Request messages, in which case it indicates the address from which the tunnel was initiated. This AVP, along with the Tunnel-Client-Endpoint and Session-Id AVP [Base], MAY be used to provide a globally unique means to identify a tunnel for accounting and auditing purposes. If Tunnel-Medium-Type is IPv4 (1), then this string is either the fully qualified domain name (FQDN) of the tunnel client machine, or it is a "dotted-decimal" IP address. Implementations MUST support the dotted-decimal format and SHOULD support the FQDN format for IP addresses. If Tunnel-Medium-Type is IPv6 (2), then this string is either the FQDN of the tunnel client machine, or it is a text representation of the address in either the preferred or alternate form [IPv6Addr]. Implementations MUST support the preferred form and SHOULD support both the alternate text form and the FQDN format for IPv6 addresses. If Tunnel-Medium-Type is not IPv4 or IPv6, this string is a tag referring to configuration data local to the Diameter client that describes the interface and medium-specific address to use. 7.6. Tunnel-Password AVP The Tunnel-Password AVP (AVP Code 69) is of type OctetString and may contain a password to be used to authenticate to a remote server. The Tunnel-Password AVP contains sensitive information. This value is not protected in the same manner as RADIUS [RADTunnels]. As required in [Base], Diameter messages are encrypted using IPsec or TLS. The Tunnel-Password AVP SHOULD NOT be used in untrusted proxy environments without encrypting it using end-to-end security techniques, such as CMS Security [DiamCMS]. 7.7. Tunnel-Private-Group-Id AVP The Tunnel-Private-Group-Id AVP (AVP Code 81) is of type OctetString, and contains the group Id for a particular tunneled session. The Calhoun et al. Expires Apr 2004 [Page 40] INTERNET-DRAFT Diameter NAS Application Oct 2003 Tunnel-Private-Group-Id AVP MAY be included in an authorization request if the tunnel initiator can pre-determine the group resulting from a particular connection and SHOULD be included in the authorization response if this tunnel session is to be treated as belonging to a particular private group. Private groups may be used to associate a tunneled session with a particular group of users. For example, it MAY be used to facilitate routing of unregistered IP addresses through a particular interface. This AVP SHOULD be included in the Accounting-Request messages which pertain to the tunneled session. 7.8. Tunnel-Assignment-Id AVP The Tunnel-Assignment-Id AVP (AVP Code 82) is of type OctetString and is used to indicate to the tunnel initiator the particular tunnel to which a session is to be assigned. Some tunneling protocols, such as [PPTP] and [L2TP], allow for sessions between the same two tunnel endpoints to be multiplexed over the same tunnel and also for a given session to utilize its own dedicated tunnel. This attribute provides a mechanism for Diameter to be used to inform the tunnel initiator (e.g. PAC, LAC) whether to assign the session to a multiplexed tunnel or to a separate tunnel. Furthermore, it allows for sessions sharing multiplexed tunnels to be assigned to different multiplexed tunnels. A particular tunneling implementation may assign differing characteristics to particular tunnels. For example, different tunnels may be assigned different QoS parameters. Such tunnels may be used to carry either individual or multiple sessions. The Tunnel- Assignment-Id attribute thus allows the Diameter server to indicate that a particular session is to be assigned to a tunnel that provides an appropriate level of service. It is expected that any QoS-related Diameter tunneling attributes defined in the future that accompany this attribute will be associated by the tunnel initiator with the Id given by this attribute. In the meantime, any semantic given to a particular Id string is a matter left to local configuration in the tunnel initiator. The Tunnel-Assignment-Id AVP is of significance only to Diameter and the tunnel initiator. The Id it specifies is intended to be of only local use to Diameter and the tunnel initiator. The Id assigned by the tunnel initiator is not conveyed to the tunnel peer. This attribute MAY be included in authorization responses. The tunnel initiator receiving this attribute MAY choose to ignore it and assign the session to an arbitrary multiplexed or non-multiplexed tunnel between the desired endpoints. This AVP SHOULD also be included in Calhoun et al. Expires Apr 2004 [Page 41] INTERNET-DRAFT Diameter NAS Application Oct 2003 the Accounting-Request messages which pertain to the tunneled session. If a tunnel initiator supports the Tunnel-Assignment-Id AVP, then it should assign a session to a tunnel in the following manner: - If this AVP is present and a tunnel exists between the specified endpoints with the specified Id, then the session should be assigned to that tunnel. - If this AVP is present and no tunnel exists between the specified endpoints with the specified Id, then a new tunnel should be established for the session and the specified Id should be associated with the new tunnel. - If this AVP is not present, then the session is assigned to an unnamed tunnel. If an unnamed tunnel does not yet exist between the specified endpoints then it is established and used for this and subsequent sessions established without the Tunnel- Assignment-Id attribute. A tunnel initiator MUST NOT assign a session for which a Tunnel-Assignment-Id AVP was not specified to a named tunnel (i.e. one that was initiated by a session specifying this AVP). Note that the same Id may be used to name different tunnels if such tunnels are between different endpoints. 7.9. Tunnel-Preference AVP The Tunnel-Preference AVP (AVP Code 83) is of type Unsigned32 and is used to identify the relative preference assigned to each tunnel when more than one set of tunneling AVPs is returned within separate Grouped-AVP AVPs. It MAY be used in an authorization request as a hint to the server that a specific preference is desired, but the server is not required to honor the hint in the corresponding response. For example, suppose that AVPs describing two tunnels are returned by the server, one with a Tunnel-Type of PPTP and the other with a Tunnel-Type of L2TP. If the tunnel initiator supports only one of the Tunnel-Types returned, it will initiate a tunnel of that type. If, however, it supports both tunnel protocols, it SHOULD use the value of the Tunnel-Preference AVP to decide which tunnel should be started. The tunnel having the numerically lowest value in the Value field of this AVP SHOULD be given the highest preference. The values assigned to two or more instances of the Tunnel-Preference AVP within a given authorization response MAY be identical. In this case, the tunnel initiator SHOULD use locally configured metrics to decide Calhoun et al. Expires Apr 2004 [Page 42] INTERNET-DRAFT Diameter NAS Application Oct 2003 which set of AVPs to use. 7.10. Tunnel-Client-Auth-Id AVP The Tunnel-Client-Auth-Id AVP (AVP Code 90) is of type UTF8String and specifies the name used by the tunnel initiator during the authentication phase of tunnel establishment. It MAY be used in an authorization request as a hint to the server that a specific preference is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST be present in the authorization response if an authentication name other than the default is desired. This AVP SHOULD be included in the Accounting- Request messages which pertain to the tunneled session. 7.11. Tunnel-Server-Auth-Id AVP The Tunnel-Server-Auth-Id AVP (AVP Code 91) is of type UTF8String and specifies the name used by the tunnel terminator during the authentication phase of tunnel establishment. It MAY be used in an authorization request as a hint to the server that a specific preference is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST be present in the authorization response if an authentication name other than the default is desired. This AVP SHOULD be included in the the Accounting-Request messages which pertain to the tunneled session. 8. NAS Accounting Applications implementing this specification use Diameter Accounting as defined in the Base [Base] with the addition of the AVPs in the following section. If accounting is active, Accounting Request messages (ACR) SHOULD be sent after the completion of any Authentication or Authorization transaction and at the end of a Session. The Accounting-Record-Type value indicates the type of event. All other AVPs identify the session and provide additional information relevant to the event. The successful completion of the first Authentication or Authorization transaction, SHOULD cause a START_RECORD should be sent. If additional Authentications or Authorizations occur in later transactions, the first exchange should generate a START_RECORD, and the later, an INTERIM_RECORD. For a given session, there MUST only be one set of matching START and STOP records, with any number of Calhoun et al. Expires Apr 2004 [Page 43] INTERNET-DRAFT Diameter NAS Application Oct 2003 INTERIM_RECORDS in between, or one EVENT_RECORD indicating the reason for not starting a session. The following table describes the AVPs, their AVP Code values, types, possible flag values and whether the AVP MAY be encrypted. +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST| | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| Accounting- 363 8.1 Unsigned64 | M | P | | V | Y | Input-Octets | | | | | | Accounting- 364 8.2 Unsigned64 | M | P | | V | Y | Output-Octets | | | | | | Accounting- 365 8.3 Unsigned64 | M | P | | V | Y | Input-Packets | | | | | | Accounting- 366 8.4 Unsigned64 | M | P | | V | Y | Output-Packets | | | | | | Acct-Session-Time 46 8.5 Unsigned32 | M | P | | V | Y | Acct-Authentic 45 8.6 Enumerated | M | P | | V | Y | Acounting-Auth- TBD 8.7 Enumerated | M | P | | V | Y | Method | | | | | | Acct-Delay-Time 41 8.8 Unsigned32 | M | P | | V | Y | Acct-Link-Count 51 8.9 Unsigned32 | M | P | | V | Y | Acct-Tunnel- 68 8.10 OctetString| M | P | | V | Y | Connection | | | | | | Acct-Tunnel- 86 8.11 Unsigned32 | M | P | | V | Y | Packets-Lost | | | | | | -----------------------------------------|----+-----+----+-----|----| 8.1. Accounting-Input-Octets AVP The Accounting-Input-Octets AVP (AVP Code 363) is of type Unsigned64, and contains the number of octets received from the user. For NAS usage, this AVP indicates how many octets have been received from the port in the course of this session and can only be present in ACR messages with an Accounting-Record-Type of INTERIM_RECORD or STOP_RECORD. 8.2. Accounting-Output-Octets AVP The Accounting-Output-Octets AVP (AVP Code 364) is of type Unsigned64, and contains the number of octets sent to the user. Calhoun et al. Expires Apr 2004 [Page 44] INTERNET-DRAFT Diameter NAS Application Oct 2003 For NAS usage, this AVP indicates how many octets have been sent to the port in the course of this session and can only be present in ACR messages with an Accounting-Record-Type of INTERIM_RECORD or STOP_RECORD. 8.3. Accounting-Input-Packets AVP The Accounting-Input-Packets (AVP Code 365) is of type Unsigned64, and contains the number of packets received from the user. For NAS usage, this AVP indicates how many packets have been received from the port over the course of a session being provided to a Framed User and can only be present in ACR messages with an Accounting- Record-Type of INTERIM_RECORD or STOP_RECORD. 8.4. Accounting-Output-Packets AVP The Accounting-Output-Packets (AVP Code 366) is of type Unsigned64, and contains the number of IP packets sent to the user. For NAS usage, this AVP indicates how many packets have been sent to the port over the course of a session being provided to a Framed User and can only be present in ACR messages with an Accounting-Record- Type of INTERIM_RECORD or STOP_RECORD. 8.5. Acct-Session-Time AVP The Acct-Session-Time AVP (AVP Code 46) is of type Unsigned32, and indicates the length of the current session in seconds. It can only be present in ACR messages with an Accounting-Record-Type of INTERIM_RECORD or STOP_RECORD. 8.6. Acct-Authentic AVP The Acct-Authentic AVP (AVP Code 45) is of type Enumerated, and specifies how the user was authenticated. The supported values are listed in [RADIUSTypes]. The following list is informational: 1 RADIUS 2 Local 3 Remote 4 Diameter Calhoun et al. Expires Apr 2004 [Page 45] INTERNET-DRAFT Diameter NAS Application Oct 2003 8.7. Accounting-Auth-Method AVP The Accounting-Auth-Method AVP (AVP Code TBD) is of type Enumerated. A NAS MAY include this AVP in an Accounting-Request message to indicate what authentication method was used to authenticate the user. (Note that this is equivalent to the RADIUS MS-Acct-Auth-Type VSA attribute). The following values are defined: 1 PAP 2 CHAP 3 MS-CHAP-1 4 MS-CHAP-2 5 EAP 7 None 8.8. Acct-Delay-Time The Acct-Delay-Time AVP (AVP Code 41) is of type Unsigned32 and indicates the number of seconds during which the Diameter client has been trying to send the Accounting-Request (ACR) which contains it. The accounting server may subtract this value from the time the ACR arrives at the server to calculate the approximate time of the event that caused the ACR to be generated. This AVP is not used for retransmissions at the transport level (TCP or SCTP). Rather, it may be used when an ACR command cannot be transmitted because there is no appropriate peer to transmit it to or was rejected because it could not be delivered to its destination. In these cases, the command MAY be buffered and transmitted some time later when an appropriate peer-connection is available or after sufficient time has passed that the destination-host may be reachable and operational. If the ACR is resent in this way the Acct-Delay- Time AVP SHOULD be included. The value of this AVP indicates the number of seconds that elapsed between the time of the first attempt at transmission and the current attempt at transmission. 8.9. Acct-Link-Count The Acct-Link-Count AVP (AVP Code 51) is of type Unsigned32 and indicates the total number of links that have been active (current or closed) in a given multilink session, at the time the accounting record is generated. This AVP MAY be included in Accounting-Requests for any session which may be part of a multilink service. The Acct-Link-Count AVP may be used to make it easier for an Calhoun et al. Expires Apr 2004 [Page 46] INTERNET-DRAFT Diameter NAS Application Oct 2003 accounting server to know when it has all the records for a given multilink service. When the number of Accounting-Requests received with Accounting-Record-Type = STOP_RECORD and the same Acct-Multi- Session-Id and unique Session-Id's equals the largest value of Acct- Link-Count seen in those Accounting-Requests, all STOP_RECORD Accounting-Requests for that multilink service have been received. The following example showing eight Accounting-Requests illustrates how the Acct-Link-Count AVP is used. In the table below, only the relevant AVPs are shown although additional AVPs containing accounting information will also be present in the Accounting- Requests. Acct-Multi- Accounting- Acct- Session-Id Session-Id Record-Type Link-Count -------------------------------------------------------- "...10" "...10" START_RECORD 1 "...10" "...11" START_RECORD 2 "...10" "...11" STOP_RECORD 2 "...10" "...12" START_RECORD 3 "...10" "...13" START_RECORD 4 "...10" "...12" STOP_RECORD 4 "...10" "...13" STOP_RECORD 4 "...10" "...10" STOP_RECORD 4 8.10. Acct-Tunnel-Connection AVP The Acct-Tunnel-Connection AVP (AVP Code 68) is of type OctetString, and contains the identifier assigned to the tunnel session. This AVP, along with the Tunnel-Client-Endpoint and Tunnel-Server-Endpoint AVPs, may be used to provide a means to uniquely identify a tunnel session for auditing purposes. The format of the identifier in this AVP depends upon the value of the Tunnel-Type AVP. For example, to fully identify an L2TP tunnel connection, the L2TP Tunnel Id and Call Id might be encoded in this field. The exact encoding of this field is implementation dependent. 8.11. Acct-Tunnel-Packets-Lost AVP The Acct-Tunnel-Packets-Lost AVP (AVP Code 86) is of type Unsigned32 and contains the number of packets lost on a given link. Calhoun et al. Expires Apr 2004 [Page 47] INTERNET-DRAFT Diameter NAS Application Oct 2003 9. RADIUS/Diameter Protocol Interactions This section describes some basic guidelines that may be used by servers that act as AAA Translation Agents. A complete description of all the differences between RADIUS and Diameter is beyond the scope of this section and document. Note that this document does not restrict implementations from creating additional methods, as long as the translation function doesn't violate the RADIUS or the Diameter protocols. There are primarily two different situations that must be handled; one where a RADIUS request is received that must be forwarded as a Diameter request, and the inverse. RADIUS does not support a peer- to-peer architecture and server initiated operations are generally not supported. See [RADDynAuth] for an alternative. Some RADIUS attributes are encrypted. RADIUS security and encryption techniques are applied on a hop-per-hop basis. A Diameter agent will have to decrypt RADIUS attribute data entering the Diameter system and if that information is forwarded, MUST secure it using Diameter specific techniques. Note that this section uses the two terms; "AVP" and "attribute" in a concise and specific manner. The former is used to signify a Diameter AVP, while the latter is used to signify a RADIUS attribute. 9.1. RADIUS Request Forwarded as Diameter Request This section describes the actions that should be followed when a Translation Agent receives a RADIUS message that is to be translated to a Diameter message. It is important to note that RADIUS servers are assumed to be stateless, and this section maintains that assumption. It is also quite possible for the RADIUS messages that comprise the session (i.e. authentication and accounting messages) will be handled by different Translation Agents in the proxy network. Therefore, a RADIUS/Diameter Translation Agent SHOULD NOT be assumed to have an accurate track on session state information. When a Translation Agent receives a RADIUS message, the following steps should be taken: - If a Message-Authenticator attribute is present, the value MUST be checked, but not included in the Diameter message. If it is incorrect, the RADIUS message should be silently discarded. The gateway system SHOULD generate and include a Message- Calhoun et al. Expires Apr 2004 [Page 48] INTERNET-DRAFT Diameter NAS Application Oct 2003 Authenticator in return RADIUS responses to this system. - The transport address of the sender MUST be checked against the NAS identifying attributes. See the description of NAS- Identifier and NAS-IP-Address below. - The Diameter Origin-Host and Origin-Realm AVPs MUST be created and added using the information from an FQDN corresponding to the NAS-IP-Address attribute (preferred if available), and/or the NAS-Identifier attribute. (Note that the RADIUS NAS- Identifier is not required to be an FQDN) The AAA protocol specified in the identity would be set to "RADIUS". - The Proxy-Info group SHOULD be added with the local server's identity being specified in the Proxy-Host AVP. This should ensure that the response is returned to this system. - The Destination-Realm AVP is created from the information found in the RADIUS User-Name attribute. - The Translation Agent must maintain transaction state information relevant to the RADIUS request, such as the Identifier field in the RADIUS header, any existing RADIUS Proxy-State attribute as well as the source IP address and port number of the UDP packet. These may be maintained locally in a state table, or may be saved in a Proxy-Info AVP group. - If the RADIUS request contained a State attribute, and the prefix of the data is "Diameter/", the data following the prefix contains the Diameter Session-Id. If no such attributes are present, and the RADIUS command is an Access-Request, a new Session-Id is created. The Session-Id is included in the Session-Id AVP. - If the RADIUS User-Password attribute is present, the password must be unencrypted using the link's RADIUS shared secret. And forwarded using Diameter security. - If the RADIUS CHAP-Password attribute is present, the Ident and Data portion of the attribute are used to create the CHAP-Auth grouped AVP. - If the RADIUS message contains an address attribute, it MUST be converted to the appropriate Diameter AVP and type. - If the RADIUS message contains Tunnel information [RADTunnels], the attributes or tagged groups should each be converted to a Diameter Tunneling Grouped AVP set. If the tunnel information contains a Tunnel-Password attribute, the RADIUS encryption must be resolved, and the password forwarded using Diameter security methods. - If the RADIUS message received is an Accounting-Request, the Acct-Status-Type attribute value must be converted to a Accounting-Record-Type AVP value. If the Acct-Status-Type attribute value is STOP, the local server MUST issue a Session- Termination-Request message once the Diameter Accounting-Answer message has been received. - If the Accounting message contains a Acct-Termination-Cause Calhoun et al. Expires Apr 2004 [Page 49] INTERNET-DRAFT Diameter NAS Application Oct 2003 attribute, it should be translated to the equivalent Termination-Cause AVP value. (see below) - If the RADIUS message contains the Accounting-Input-Octets, Accounting-Input-Packets, Accounting-Output-Octets or Accounting-Output-Packets, these attributes must be converted to the Diameter equivalent ones. Further, if the Acct-Input- Gigawords or Acct-Output-Gigawords attributes are present, these must be used to properly compute the Diameter accounting AVPs. The corresponding Diameter response is always guaranteed to be received by the same Translation Agent that translated the original request, due to the contents of the Origin-Host AVP in the Diameter request. The following steps are applied to the response message during the Diameter to RADIUS translation: - If the Diameter Command-Code is set to AA-Answer and the Result- Code AVP is set to DIAMETER_MULTI_ROUND_AUTH, the gateway must send a RADIUS Access-Challenge with the Diameter Session-Id and the Origin-Host AVPs encapsulated in the RADIUS State attribute, with the prefix "Diameter/". This is necessary in order to ensure that the Translation Agent that will receive the subsequent RADIUS Access-Request will have access to the Session Identifier, and be able to set the Destination-Host to the correct value. If the Multi-Round-Time-Out AVP is present, the value of the AVP MUST be inserted in the RADIUS Session-Timeout AVP. - If the Command-Code is set to AA-Answer, the Diameter Session-Id AVP is saved in a new RADIUS Class attribute, whose format consists of the string "Diameter/" followed by the Diameter Session Identifier. This will ensure that the subsequent Accounting messages, which could be received by any Translation Agent, would have access to the original Diameter Session Identifier. - If a Proxy-State attribute was present in the RADIUS request, the same attribute is added in the response. This information may be found in the Proxy-Info AVP group, or in a local state table. - If state information regarding the RADIUS request was saved in a Proxy-Info AVP or local state table, the RADIUS Identifier and UDP IP Address and port number are extracted and used in issuing the RADIUS reply. When translating a Diameter AA-Answer (with successful result code) to RADIUS Access-Accept, that contains a Session-Timeout or Authorization-Lifetime AVP; - If the Diameter message contains a Session-Timeout AVP but no Authorization-Lifetime AVP, translate it to Session-Timeout Calhoun et al. Expires Apr 2004 [Page 50] INTERNET-DRAFT Diameter NAS Application Oct 2003 attribute (and no Termination-Action). - If the Diameter message contains a Authorization-Lifetime AVP but no Session-Timeout AVP, translate it to Session-Timeout attribute and Termination-Action set to AA-REQUEST. (And remove Authorization-Lifetime and Re-Auth-Request-Type) - If the Diameter message has both, the Session-Timeout is always greater or equal than Authorization-Lifetime (required by Base). I guess the safest bet is to translate it to Session-Timeout value (with value from Authorization-Lifetime AVP, the smaller one) and Termination-Action set to AA-REQUEST. (And remove Authorization-Lifetime and Re-Auth-Request-Type) As described in Section 3.2 of [RADDynAuth], a Service-Type of "Authorize Only" is used in a Disconnect-Request or CoA-Request message, in order to allow for easier translation between RADIUS and Diameter. In order to simplify implementation, a RADIUS/Diameter gateway receiving a RADIUS Disconnect-Request without a Service-Type value of "Authorize Only" MAY reply with a Disconnect-Nak with an Error-Cause attribute with value 405," Unsupported Service" and no Service-Type attribute. Similarly, a RADIUS/Diameter gateway receiving a RADIUS CoA-Request without a Service-Type value of "Authorize Only" MAY reply with a CoA-Nak with an Error-Cause attribute with value 405, "Unsupported Service" and no Service-Type attribute. When included within a RADIUS Disconnect-Request or CoA-Request, a Service-Type Attribute with value "Authorize Only" indicates that the Request only contains NAS and session identification attributes. A RADIUS CoA-Request is translated to a Diameter Re-Authorization Request (RAR), and a RADIUS Disconnect-Request is translated to a Diameter Session-Termination-Request (STR). A Diameter Re-Authorization Request (RAR) message will receive a Diameter Re-Authorization Answer (RAA) reply which is translated to a RADIUS CoA-NAK containing a Service-Type Attribute with value "Authorize Only" and an Error-Cause Attribute with value "Request Initiated." A Diameter Session-Termination-Request (STR) message will receive a Diameter Session-Termination-Answer (STA) message reply which is tranlated to a RADIUS Disconnect-Nak containing a Service-Type Attribute with value "Authorize Only" and an Error-Cause Attribute with value "Request Initiated." After a Diameter Re-Authorization Answer (RAA) is sent, a Diameter AA-Request will then be sent and is translated to a RADIUS Access- Calhoun et al. Expires Apr 2004 [Page 51] INTERNET-DRAFT Diameter NAS Application Oct 2003 Request with a Service-Type attribute with value "Authorize Only", attempting reauthorization. This Access-Request contains the NAS attributes from the CoA-Request, as well as the session attributes from the Request legal for inclusion in an Access-Request. The RADIUS server will send back an Access-Accept to (re-)authorize the session or an Access-Reject to refuse to (re-)authorize it. This is translated to a Diameter AA-Answer. After a Diameter Session-Termination-Answer (STA) is sent, a Diameter Abort-Session-Request (ASR) will be sent and is translated to a RADIUS Access-Request with a Service-Type attribute with value "Authorize Only", attempting reauthorization. This Access-Request contains the NAS and session attributes from the Disconnect-Rquest. The RADIUS server send back an Access-Reject to terminate the session. This is translated to a Diameter Abort-Session-Answer (ASA)." 9.2. Diameter Request Forwarded as RADIUS Request When a server receives a Diameter request that is to be forwarded to a RADIUS entity, the following steps are an example of the steps that may be followed: - The Origin-Host AVP's value is inserted in the NAS-Identifier attribute. - The following information MUST be present in the corresponding Diameter response, and therefore MUST be saved either in a local state table, or encoded in a RADIUS Proxy-State attribute: 1. Origin-Host AVP 2. Session-Id AVP 3. Proxy-Info AVP 4. Any other AVP that MUST be present in the response, and has no corresponding RADIUS attribute. - If the CHAP-Auth AVP is present, the grouped AVPs are used to create the RADIUS CHAP-Password attribute data. - If the User-Password AVP is present, the data should be encrypted using RADIUS rules. Likewise for any other encrypted attribute values. - AVPs that are of the type Address, must be translated to the corresponding RADIUS attribute. - If the Accounting-Input-Octets, Accounting-Input-Packets, Accounting-Output-Octets or Accounting-Output-Packets AVPs are present, these must be translated to the corresponding RADIUS attributes. Further, the value of the Diameter AVPs do not fit within a 32-bit RADIUS attribute, the RADIUS Acct-Input- Gigawords and Acct-Output-Gigawords must be used. Calhoun et al. Expires Apr 2004 [Page 52] INTERNET-DRAFT Diameter NAS Application Oct 2003 - If the RADIUS link supports the Message-Authenticator attribute [RADIUSExt] it SHOULD be generated and added to the request. When the corresponding response is received by the Translation Agent, which is guaranteed in the RADIUS protocol, the following steps may be followed: - If the RADIUS code is set to Access-Challenge, a Diameter AA- Answer message is created with the Result-Code set to DIAMETER_MULTI_ROUND_AUTH. If the Session-Timeout AVP is present in the RADIUS message, its value is inserted in the Multi-Round- Time-Out AVP. - If a Proxy-State attribute is present, extract the encoded information, otherwise retrieve the original Proxy-Info AVP group information from the local state table. - The response's Origin-Host information is created from the FQDN of the source IP address of the RADIUS message. The same FQDN is also stored to a Route-Record AVP. - The response's Destination-Host AVP is copied from the saved request's Origin-Host information. - The Acct-Session-Id information is added to the Session-Id AVP. - If a Proxy-Info AVP was present in the request, the same AVP MUST be added to the response. - If the RADIUS State attributes are present, these attributes must be present in the Diameter response. - Any other AVPs that were saved at request time, and MUST be present in the response, are added to the message. When translating a RADIUS Access-Accept to Diameter AA-Answer, that contains a Session-Timeout attribute, do the following: - If the RADIUS message contains a Session-Timeout attribute and a Termination-Action attribute set to DEFAULT (or no Termination- Action attribute at all), translate it to AA-Answer with a Session-Timeout AVP, and remove the Termination-Action attribute. - If the RADIUS message contains a Session-Timeout attribute and a Termination-Action attribute set to AA-REQUEST, translate it to AA-Answer with Authorization-Lifetime AVP and Re-Auth-Request- Type set to AUTHORIZE_AUTHENTICATE, and remove the Session- Timeout attribute. If the Diameter/RADIUS gateway supports [RADDynAuth], it may translate a Diameter Re-Authorization-Request (RAR) message to a RADIUS CoA-Request with a Service-Type value of "Authorization Only". It is possible that the NAS receiving this message will not support [RADDynAuth], in which case an ICMP Port Unreachable message will be returned to the Diameter/RADIUS gateway. However, even if the NAS Calhoun et al. Expires Apr 2004 [Page 53] INTERNET-DRAFT Diameter NAS Application Oct 2003 supports [RADDynAuth], it may not support a Service-Type value of "Authorization Only" in a CoA-Request message. In this case it will respond with a CoA-Nak and (optionally) an Error-Cause attribute with value 405, "Unsupported Service" and no Service-Type attribute. If a Diameter/RADIUS gateway receives such a packet, or an ICMP port unreachable message, or if it does not support [RADDynAuth], then it SHOULD reply to the AAA server with a Diameter Re-Authorization- Answer (RAA) message with a Result-Code AVP of "DIAMETER_COMMAND_UNSUPPORTED". If in response to a CoA-Request sent to the NAS, the Diameter/RADIUS gateway receives a RADIUS CoA-NAK containing a Service-Type Attribute with value "Authorize Only" and an Error-Cause Attribute with value "Request Initiated", this is translated to a Diameter Re- Authorization-Answer (RAA) with a Result-Code AVP of "DIAMETER_LIMITED_SUCCESS" sent to the AAA server. Subsequently, the Diameter/RADIUS gateway should receive a RADIUS Access-Request from the NAS, with a Service-Type of "Authorize Only". This is translated to a Diameter AA-Request with an Auth-Request-Type AVP of AUTHORIZE_ONLY, sent to the AAA server. The AAA server will then reply with a Diameter AA-Answer, which is translated to a RADIUS Access-Accept or Access-Reject, depending on the value of the Result- Code AVP. A Diameter/RADIUS gateway supporting [RADDynAuth] may translate a Diameter Session-Termination-Request (STR) message received from the AAA server to a RADIUS Disconnect-Request with a Service-Type value of "Authorization Only", sent to the NAS. It is possible that the NAS receiving this message will not support [RADDynAuth], in which case an ICMP Port Unreachable message will be returned to the Diameter/RADIUS gateway. Even if the NAS supports [RADDynAuth], it may not support a Service-Type value of "Authorization Only" in a Disconnect-Request message. In this case it will respond with a CoA-Nak and (optionally) an Error-Cause attribute with value 405," Unsupported Service" and no Service-Type attribute. If the Diameter/RADIUS gateway encounters these error conditions, or if it does not support [RADDynAuth], it sends a Diameter Re-Authorization-Answer (RAA) message with an Result-Code AVP of "DIAMETER_COMMAND_UNSUPPORTED" to the AAA server. If the NAS does support [RADDynAuth] and a Disconnect-Request message with a Service-Type value of "Authorize Only" it will typically reply with a RADIUS Disconnect-NAK containing a Service-Type Attribute with value "Authorize Only" and an Error-Cause Attribute with value "Request Initiated". A Diameter/RADIUS gateway supporting [RADDynAuth] translates this to a Diameter Session-Termination-Answer Calhoun et al. Expires Apr 2004 [Page 54] INTERNET-DRAFT Diameter NAS Application Oct 2003 (STA) with a Result-Code AVP of "DIAMETER_LIMITED_SUCCESS", sent to the AAA Server. Subsequently, the Diameter/RADIUS gateway should receive a RADIUS Access-Request from the NAS, with a Service-Type of "Authorize Only". This is translated to a Diameter Abort-Session-Request (ASR), sent to the AAA server. The AAA server will then reply with a Diameter Abort- Session-Answer (ASA), which the Diameter/RADIUS gateway translates to a RADIUS Access-Reject sent to the NAS. 9.3. AVPs Used Only for Compatibility The AVPs defined in this section SHOULD only used for backwards compatibility when a Diameter/RADIUS translation function is invoked, and are not typically originated by Diameter systems during normal operations. +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST| | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| NAS-Identifier 32 9.3.1 UTF8String | M | P | | V | Y | NAS-IP-Address 4 9.3.2 OctetString| M | P | | V | Y | NAS-IPv6-Address 95 9.3.3 OctetString| M | P | | V | Y | State 24 9.3.4 OctetString| M | P | | V | Y | Termination- 295 9.3.5 Enumerated | M | P | | V | Y | Cause | | | | | | -----------------------------------------|----+-----+----+-----|----| 9.3.1. NAS-Identifier AVP The NAS-Identifier AVP (AVP Code 32) [RADIUS] is of type UTF8String and contains the identity of the NAS providing service to the user. This AVP SHOULD only be added by a RADIUS/Diameter Translation Agent. When this AVP is present, the Origin-Host AVP identifies the RADIUS/Diameter Translation Agent rather than the NAS providing service to the user. In RADIUS it would be possible for a rogue NAS to forge the NAS- Identifier attribute. Diameter/RADIUS translation agents SHOULD attempt to check a received NAS-Identifier attribute against the source address of the RADIUS packet, by doing an A/AAAA RR query. If the NAS-Identifier attribute contains an FQDN, then such a query would resolve to an IP address matching the source address. However, Calhoun et al. Expires Apr 2004 [Page 55] INTERNET-DRAFT Diameter NAS Application Oct 2003 the NAS-Identifier attribute is not required to contain an FQDN, so such a query could fail. In this case, an error should be logged, but no other action taken, other than doing a reverse lookup on the source address and inserting the resulting FQDN into the Route-Record AVP. Diameter agents and servers SHOULD check whether a NAS-Identifier AVP corresponds to an entry in the Route-Record AVP. If no match is found, then an error is logged, but no other action is taken. 9.3.2. NAS-IP-Address AVP The NAS-IP-Address AVP (AVP Code 4) [RADIUS] is of type OctetString, and contains the IP Address of the NAS providing service to the user. This AVP SHOULD only be added by a RADIUS/Diameter Translation Agent. When this AVP is present, the Origin-Host AVP identifies the RADIUS/Diameter Translation Agent rather than the NAS providing service to the user. In RADIUS it would be possible for a rogue NAS to forge the NAS-IP- Address attribute value. Diameter/RADIUS translation agents MUST check a received NAS-IP-Address or NAS-IPv6-Address attribute against the source address of the RADIUS packet. If they do not match, and the Diameter/RADIUS translation agent does not know whether the packet was sent by a RADIUS proxy or NAS (e.g. no Proxy-State attribute) then by default it is assumed that the source address corresponds to a RADIUS proxy, and that the NAS Address is behind that proxy, potentially with some additional RADIUS proxies in between. The Diameter/RADIUS translation agent MUST insert entries in the Route-Record AVP corresponding to the apparent route. This implies doing a reverse lookup on the source address and NAS-IP- Address, or NAS-IPv6-Address attributes in order to determine the corresponding FQDNs. If the source address and the NAS-IP-Address, or NAS-IPv6-Address do not match, and the Diameter/RADIUS translation agent knows that it is talking directly to the NAS (e.g. no RADIUS proxies between it and the NAS), then the error should be logged, and the packet MUST be discarded. Diameter agents and servers MUST check whether the NAS-IP-Address AVP corresponds to an entry in the Route-Record AVP. This is done by doing a reverse lookup (PTR RR) for the NAS-IP-Address to retrieve the corresponding FQDN, and checking for a match with the Route- Record AVP. If no match is found, then an error is logged, but no other action is taken. Calhoun et al. Expires Apr 2004 [Page 56] INTERNET-DRAFT Diameter NAS Application Oct 2003 9.3.3. NAS-IPv6-Address AVP The NAS-IPv6-Address AVP (AVP Code 95) [RADIUSIPv6] is of type OctetString, and contains the IPv6 Address of the NAS providing service to the user. This AVP SHOULD only be added by a RADIUS/Diameter Translation Agent. When this AVP is present, the Origin-Host AVP identifies the RADIUS/Diameter Translation Agent rather than the NAS providing service to the user. In RADIUS it would be possible for a rogue NAS to forge the NAS- IPv6-Address attribute. Diameter/RADIUS translation agents MUST check a received NAS-IPv6-Address attribute against the source address of the RADIUS packet. If they do not match, and the Diameter/RADIUS translation agent does not know whether the packet was sent by a RADIUS proxy or NAS (e.g. no Proxy-State attribute) then by default it is assumed that the source address corresponds to a RADIUS proxy, and that the NAS-IPv6-Address is behind that proxy, potentially with some additional RADIUS proxies in between. The Diameter/RADIUS translation agent MUST insert entries in the Route-Record AVP corresponding to the apparent route. This implies doing a reverse lookup on the source address and NAS-IPv6-Address attributes in order to determine the corresponding FQDNs. If the source address and the NAS-IPv6-Address do not match, and the Diameter/RADIUS translation agent knows that it is talking directly to the NAS (e.g. no RADIUS proxies between it and the NAS), then the error should be logged, and the packet MUST be discarded. Diameter agents and servers MUST check whether the NAS-IPv6-Address AVP corresponds to an entry in the Route-Record AVP. This is done by doing a reverse lookup (PTR RR) for the NAS-IPv6-Address to retrieve the corresponding FQDN, and checking for a match with the Record- Route AVP. If no match is found, then an error is logged, but no other action is taken. 9.3.4. State AVP The State AVP (AVP Code 24) [RADIUS] is of type OctetString and has two uses in the Diameter NAS application. The State AVP MAY be sent by a Diameter Server to a NAS in an AA- Response command that contains a Result-Code of DIAMETER_MULTI_ROUND_AUTH. If so, the NAS MUST return it unmodified in the subsequent AA-Request command. The State AVP MAY also be sent by a Diameter Server to a NAS in an AA-Response command that also includes a Termination-Action AVP with Calhoun et al. Expires Apr 2004 [Page 57] INTERNET-DRAFT Diameter NAS Application Oct 2003 the value of AA-REQUEST. If the NAS performs the Termination-Action by sending a new AA-Request command upon termination of the current service, it MUST return the State AVP unmodified in the new request command. In either usage the NAS MUST NOT interpret the AVP locally. Usage of the State AVP is implementation dependent. 9.3.5. Termination-Cause AVP Code Values This section defines a mapping between Termination-Cause AVP code values and RADIUS Acct-Terminate-Cause attribute code values from RFC 2866 [RADIUSAcct] and [RADIUSTypes], thereby allowing a RADIUS/Diameter Translation Agent to convert between the attribute and AVP values. This section thus extends the definitions in the "Termination-Cause AVP" section of the Base Diameter specification. The table in this section defines the mapping between Termination- Cause AVP and RADIUS Acct-Terminate-Cause causes. Calhoun et al. Expires Apr 2004 [Page 58] INTERNET-DRAFT Diameter NAS Application Oct 2003 +-----------------------+ | Value | +-----------+-----------+ Cause Value Name | RADIUS | Diameter | ------------------------------|-----------+-----------+ User Request | 1 | 11 | Lost Carrier | 2 | 12 | Lost Service | 3 | 13 | Idle Timeout | 4 | 14 | Session Timeout | 5 | 15 | Admin Reset | 6 | 16 | Admin Reboot | 7 | 17 | Port Error | 8 | 18 | NAS Error | 9 | 19 | NAS Request | 10 | 20 | NAS Reboot | 11 | 21 | Port Unneeded | 12 | 22 | Port Preempted | 13 | 23 | Port Suspended | 14 | 24 | Service Unavailable | 15 | 25 | Callback | 16 | 26 | User Error | 17 | 27 | Host Request | 18 | 28 | Supplicant Restart | 19 | 29 | [RAD802.1X] Reauthentication Failure | 20 | 30 | [RAD802.1X] Port Reinit | 21 | 31 | [RAD802.1X] Port Disabled | 22 | 32 | [RAD802.1X] ------------------------------|-----------+-----------+ From RFC 2866, the termination causes are as follows: User Request User requested termination of service, for example with LCP Terminate or by logging out. Lost Carrier DCD was dropped on the port. Lost Service Service can no longer be provided; for example, user's connection to a host was interrupted. Idle Timeout Idle timer expired. Session Timeout Maximum session length timer expired. Admin Reset Administrator reset the port or session. Admin Reboot Administrator is ending service on the NAS, Calhoun et al. Expires Apr 2004 [Page 59] INTERNET-DRAFT Diameter NAS Application Oct 2003 for example prior to rebooting the NAS. Port Error NAS detected an error on the port which required ending the session. NAS Error NAS detected some error (other than on the port) which required ending the session. NAS Request NAS ended session for a non-error reason not otherwise listed here. NAS Reboot The NAS ended the session in order to reboot non-administratively ("crash"). Port Unneeded NAS ended session because resource usage fell below low-water mark (for example, if a bandwidth-on-demand algorithm decided that the port was no longer needed). Port Preempted NAS ended session in order to allocate the port to a higher priority use. Port Suspended NAS ended session to suspend a virtual session. Service Unavailable NAS was unable to provide requested service. Callback NAS is terminating current session in order to perform callback for a new session. User Error Input from user is in error, causing termination of session. Host Request Login Host terminated session normally. 9.4. Prohibited RADIUS Attributes The following RADIUS attributes MUST NOT appear in a Diameter message. Instead, they are translated to other Diameter AVPs or handled in some special manner. The rules for the treatment of the attributes are discussed in Sections 9.1, 9.2 and 9.6. Calhoun et al. Expires Apr 2004 [Page 60] INTERNET-DRAFT Diameter NAS Application Oct 2003 Attribute Description Defined Nearest Diameter AVP ----------------------------------------------------------------- 3 CHAP-Password RFC 2865 CHAP-Auth Group 26 Vendor-Specific RFC 2865 Vendor Specific AVP 29 Termination-Action RFC 2865 Authorization-Lifetime 40 Acct-Status-Type RFC 2866 Accounting-Record-Type 42 Acct-Input-Octets RFC 2866 Accounting-Input-Octets 43 Acct-Output-Octets RFC 2866 Accounting-Output-Octets 47 Acct-Input-Packets RFC 2866 Accounting-Input-Packets 48 Acct-Output-Packets RFC 2866 Accounting-Output-Packets 49 Acct-Terminate-Cause RFC 2866 Termination-Cause 52 Acct-Input-Gigawords RFC 2869 Accounting-Input-Octets 53 Acct-Output-Gigawords RFC 2869 Accounting-Output-Octets 80 Message-Authenticator RFC 2869 none - check and discard 9.5. Translatable Diameter AVPs In general, Diameter AVPs that are not RADIUS compatible have code values greater than 255. The table in the section above shows the AVPs that can be converted into RADIUS attributes. Another problem may occur with Diameter AVP values that may be more than 253 octets in length. Some RADIUS attributes ( including but not limited to: (8)Reply-Message, (79)EAP-Message, and (77)Connect- Info ) allow concatenation of multiple instances to overcome this limitation. If this is not possible, a Result-Code of DIAMETER_INVALID_AVP_LENGTH should be returned. 9.6. RADIUS Vendor Specific Attributes RADIUS supports the inclusion of Vendor Specific Attributes (VSAs) through the use of attribute 26. The recommended format [RADIUS] of the attribute data field includes a 4 octet vendor code followed by a one octet vendor type field and a one octet length field. The last two fields MAY be repeated. 9.6.1. Forwarding a Diameter Vendor AVP as a RADIUS VSA The RADIUS VSA attribute should consist of the following fields; RADIUS Type = 26, Vendor Specific Attribute RADIUS Length = total length of attribute (header + data) RADIUS Vendor code = Diameter Vendor code RADIUS Vendor type code = low order byte of Diameter AVP code RADIUS Vendor data length = length of Diameter data Calhoun et al. Expires Apr 2004 [Page 61] INTERNET-DRAFT Diameter NAS Application Oct 2003 (not including padding) If the Diameter AVP code is greater than 255, then the RADIUS speaking code may use a Vendor specific field coding, if it knows one for that vendor. Otherwise, the AVP will be ignored. Unless it is flagged as Mandatory, in which case an "DIAMETER_AVP_UNSUPPORTED" Result-Code will be returned, and the RADIUS message will not be sent. 9.6.2. Forwarding a RADIUS VSA to a Diameter Vendor AVP The Diameter AVP will consist of the following fields; Diameter Flags: V=1, M=0, P=0 Diameter Vendor code = RADIUS VSA Vendor code Diameter AVP code = RADIUS VSA Vendor type code Diameter AVP length = length of AVP (header + data + padding) Diameter Data = RADIUS VSA vendor data NOTE: that the VSAs are considered as optional by RADIUS rules, and this specification does not set the Mandatory flag. If a VSA is desired to be made mandatory, because it represents a required service policy, the RADIUS gateway should have a process to set the bit on the Diameter side. If the RADIUS receiving code knows of vendor specific fields interpretations for the specific vendor, it may employ them to parse an extended AVP code or data length, Otherwise the recommended standard fields will be used. Nested Multiple vendor data fields MUST be expanded into multiple Diameter AVPs. Calhoun et al. Expires Apr 2004 [Page 62] INTERNET-DRAFT Diameter NAS Application Oct 2003 10. AVP Occurrence Tables The following tables present the AVPs used by NAS applications, in NAS messages, and specify in which Diameter messages they MAY, or MAY NOT be present. [Base] messages and AVPs are not described in this document. Note that AVPs that can only be present within a Grouped AVP are not represented in this table. The table uses the following symbols: 0 The AVP MUST NOT be present in the message. 0+ Zero or more instances of the AVP MAY be present in the message. 0-1 Zero or one instance of the AVP MAY be present in the message. 1 One instance of the AVP MUST be present in the message. 10.1. AA-Request/Answer AVP Table The table in this section is limited to the Command Codes defined in this specification. Calhoun et al. Expires Apr 2004 [Page 63] INTERNET-DRAFT Diameter NAS Application Oct 2003 +-----------+ | Command | |-----+-----+ Attribute Name | AAR | AAA | ------------------------------|-----+-----+ Acct-Interim-Interval | 0 | 0-1 | ARAP-Challenge-Response | 0 | 0-1 | ARAP-Features | 0 | 0-1 | ARAP-Password | 0-1 | 0 | ARAP-Security | 0-1 | 0-1 | ARAP-Security-Data | 0+ | 0+ | ARAP-Zone-Access | 0 | 0-1 | Auth-Application-Id | 1 | 1 | Auth-Grace-Period | 0-1 | 0-1 | Auth-Request-Type | 1 | 1 | Auth-Session-State | 0-1 | 0-1 | Authorization-Lifetime | 0-1 | 0-1 | Callback-Id | 0 | 0-1 | Callback-Number | 0-1 | 0-1 | Called-Station-Id | 0-1 | 0 | Calling-Station-Id | 0-1 | 0 | CHAP-Auth | 0-1 | 0 | CHAP-Challenge | 0-1 | 0 | Class | 0 | 0+ | Configuration-Token | 0 | 0+ | Connect-Info | 0-1 | 0 | Destination-Host | 0-1 | 0 | Destination-Realm | 1 | 0 | Error-Message | 0 | 0-1 | Error-Reporting-Host | 0 | 0-1 | Failed-AVP | 0+ | 0+ | Filter-Id | 0 | 0+ | Framed-Appletalk-Link | 0 | 0-1 | Framed-Appletalk-Network | 0 | 0+ | Framed-Appletalk-Zone | 0 | 0-1 | Framed-Compression | 0+ | 0+ | Framed-Interface-Id | 0-1 | 0-1 | Framed-IP-Address | 0-1 | 0-1 | Framed-IP-Netmask | 0-1 | 0-1 | Framed-IPv6-Prefix | 0+ | 0+ | Framed-IPv6-Pool | 0 | 0-1 | Framed-IPv6-Route | 0 | 0+ | Framed-IPX-Network | 0 | 0-1 | Framed-MTU | 0-1 | 0-1 | Framed-Pool | 0 | 0-1 | Framed-Protocol | 0-1 | 0-1 | Framed-Route | 0 | 0+ | ------------------------------|-----+-----+ Calhoun et al. Expires Apr 2004 [Page 64] INTERNET-DRAFT Diameter NAS Application Oct 2003 +-----------+ | Command | |-----+-----+ Attribute Name | AAR | AAA | ------------------------------|-----+-----+ Framed-Routing | 0 | 0-1 | Idle-Timeout | 0 | 0-1 | Login-IP-Host | 0+ | 0+ | Login-IPv6-Host | 0+ | 0+ | Login-LAT-Group | 0-1 | 0-1 | Login-LAT-Node | 0-1 | 0-1 | Login-LAT-Port | 0-1 | 0-1 | Login-LAT-Service | 0-1 | 0-1 | Login-Service | 0 | 0-1 | Login-TCP-Port | 0 | 0-1 | Multi-Round-Time-Out | 0 | 0-1 | NAS-Filter-Rule | 0 | 0+ | NAS-Identifier | 0-1 | 0 | NAS-IP-Address | 0-1 | 0 | NAS-IPv6-Address | 0-1 | 0 | NAS-Port | 0-1 | 0 | NAS-Port-Id | 0-1 | 0 | NAS-Port-Type | 0-1 | 0 | Originating-Line-Info | 0-1 | 0 | Origin-Host | 1 | 1 | Origin-Realm | 1 | 1 | Origin-State-Id | 0-1 | 0-1 | Password-Retry | 0 | 0-1 | Port-Limit | 0-1 | 0-1 | Prompt | 0 | 0-1 | Proxy-Info | 0+ | 0+ | Re-Auth-Request-Type | 0 | 0-1 | Redirect-Host | 0 | 0+ | Redirect-Host-Usage | 0 | 0-1 | Redirect-Max-Cache-Time | 0 | 0-1 | Reply-Message | 0 | 0+ | Result-Code | 0 | 1 | Route-Record | 0+ | 0+ | Service-Type | 0-1 | 0-1 | Session-Id | 1 | 1 | Session-Timeout | 0 | 0-1 | State | 0-1 | 0-1 | Tunneling | 0+ | 0+ | User-Name | 0-1 | 0-1 | User-Password | 0-1 | 0 | ------------------------------|-----+-----+ Calhoun et al. Expires Apr 2004 [Page 65] INTERNET-DRAFT Diameter NAS Application Oct 2003 10.2. Accounting AVP Tables The tables in this section are used to represent which AVPs defined in this document are to be present and used in NAS application Accounting messages. These AVPs are defined in this document, as well as [Base] and [RADIUSAcct]. 10.2.1. Accounting Framed Access AVP Table The table in this section is used when the Service-Type specifies Framed Access. +-----------+ | Command | |-----+-----+ Attribute Name | ACR | ACA | ---------------------------------------|-----+-----+ Accounting-Auth-Method | 0-1 | 0 | Accounting-Input-Octets | 1 | 0 | Accounting-Input-Packets | 1 | 0 | Accounting-Output-Octets | 1 | 0 | Accounting-Output-Packets | 1 | 0 | Accounting-Record-Type | 1 | 1 | Accounting-Record-Number | 0-1 | 0-1 | Accounting-Realtime-Required | 0-1 | 0 | Accounting-Sub-Session-Id | 0-1 | 0-1 | Acct-Application-Id | 0-1 | 0-1 | Acct-Session-Id | 0-1 | 0-1 | Acct-Multi-Session-Id | 0-1 | 0-1 | Acct-Authentic | 1 | 0 | Acct-Delay-Time | 0-1 | 0 | Acct-Interim-Interval | 0-1 | 0 | Acct-Link-Count | 0-1 | 0 | Acct-Session-Time | 1 | 0 | Acct-Tunnel-Connection | 0-1 | 0 | Acct-Tunnel-Packets-Lost | 0-1 | 0 | Connection-Info | 0+ | 0 | Event-Timestamp | 0-1 | 0-1 | Error-Reporting-Host | 0 | 0-1 | Framed-AppleTalk-Link | 0-1 | 0 | Framed-AppleTalk-Network | 0-1 | 0 | Framed-AppleTalk-Zone | 0-1 | 0 | Framed-Compression | 0-1 | 0 | ---------------------------------------|-----+-----+ Calhoun et al. Expires Apr 2004 [Page 66] INTERNET-DRAFT Diameter NAS Application Oct 2003 +-----------+ | Command | |-----+-----+ Attribute Name | ACR | ACA | ---------------------------------------|-----+-----+ Framed-IP-Address | 0-1 | 0 | Framed-IP-Netmask | 0-1 | 0 | Framed-IPv6-Pool | 0-1 | 0 | Framed-IPX-Network | 0-1 | 0 | Framed-MTU | 0-1 | 0 | Framed-Pool | 0-1 | 0 | Framed-Protocol | 0-1 | 0 | Framed-Route | 0-1 | 0 | Framed-Routing | 0-1 | 0 | NAS-Filter-Rule | 0-1 | 0 | NAS-Identifier | 0-1 | 0-1 | NAS-IP-Address | 0-1 | 0-1 | NAS-IPv6-Address | 0-1 | 0-1 | NAS-Port | 0-1 | 0-1 | NAS-Port-Id | 0-1 | 0-1 | NAS-Port-Type | 0-1 | 0-1 | Origin-Host | 1 | 1 | Origin-Realm | 1 | 1 | Origin-State-Id | 0-1 | 0-1 | Proxy-Info | 0+ | 0+ | Route-Record | 0+ | 0+ | Service-Type | 0-1 | 0-1 | Termination-Cause | 0-1 | 0-1 | Tunnel-Assignment-Id | 0-1 | 0 | Tunnel-Client-Endpoint | 0-1 | 0 | Tunnel-Medium-Type | 0-1 | 0 | Tunnel-Private-Group-Id | 0-1 | 0 | Tunnel-Server-Endpoint | 0-1 | 0 | Tunnel-Type | 0-1 | 0 | User-Name | 0-1 | 0-1 | Vendor-Specific-Application-Id | 0-1 | 0-1 | ---------------------------------------|-----+-----+ 10.2.2. Accounting Non-Framed Access AVP Table The table in this section is used when the Service-Type specifies Non-Framed Access. Calhoun et al. Expires Apr 2004 [Page 67] INTERNET-DRAFT Diameter NAS Application Oct 2003 +-----------+ | Command | |-----+-----+ Attribute Name | ACR | ACA | ---------------------------------------|-----+-----+ Accounting-Auth-Method | 0-1 | 0 | Accounting-Input-Octets | 1 | 0 | Accounting-Output-Octets | 1 | 0 | Accounting-Record-Type | 1 | 1 | Accounting-Record-Number | 0-1 | 0-1 | Accounting-Realtime-Required | 0-1 | 0 | Accounting-Sub-Session-Id | 0-1 | 0-1 | Acct-Application-Id | 1 | 1 | Acct-Session-Id | 1 | 0-1 | Acct-Multi-Session-Id | 0-1 | 0-1 | Acct-Authentic | 1 | 0 | Acct-Delay-Time | 0-1 | 0 | Acct-Interim-Interval | 0-1 | 0 | Acct-Link-Count | 0-1 | 0 | Acct-Session-Time | 1 | 0 | Event-Timestamp | 0-1 | 0-1 | Error-Reporting-Host | 0 | 0-1 | Login-IP-Host | 0+ | 0 | Login-IPv6-Host | 0+ | 0 | Login-LAT-Service | 0-1 | 0 | Login-LAT-Node | 0-1 | 0 | Login-LAT-Group | 0-1 | 0 | Login-LAT-Port | 0-1 | 0 | Login-Service | 0-1 | 0 | Login-TCP-Port | 0-1 | 0 | NAS-Identifier | 0-1 | 0-1 | NAS-IP-Address | 0-1 | 0-1 | NAS-IPv6-Address | 0-1 | 0-1 | NAS-Port | 0-1 | 0-1 | NAS-Port-Id | 0-1 | 0-1 | NAS-Port-Type | 0-1 | 0-1 | Origin-Host | 1 | 1 | Origin-Realm | 1 | 1 | Origin-State-Id | 0-1 | 0-1 | Proxy-Info | 0+ | 0+ | Route-Record | 0+ | 0+ | Service-Type | 0-1 | 0-1 | Termination-Cause | 0-1 | 0-1 | User-Name | 0-1 | 0-1 | Vendor-Specific-Application-Id | 0-1 | 0-1 | ---------------------------------------|-----+-----+ Calhoun et al. Expires Apr 2004 [Page 68] INTERNET-DRAFT Diameter NAS Application Oct 2003 11. IANA Considerations This section provides guidance to the Internet Assigned Numbers Authority (IANA) regarding registration of values related to the Diameter protocol, in accordance with BCP 26 [IANAConsid]. This document defines values in the namespaces that have created and defined in the Diameter Base [Base]. The IANA Considerations section of that document details the assignment criteria. Values assigned in this document, or by future IANA action, must be coordinated within this shared namespace. 11.1. Command Codes This specification assigns the values 265 and 268 from the Command Code namespace defined in [Base]. See sections 3.1 and 3.2 for the assignment of the namespace in this specification. 11.2. AVP Codes This specification assigns the values 363-366 and 400-405 from the AVP Code namespace defined in [Base]. See sections 4, and 5 for the assignment of the namespace in this specification. Note that the values 363-366 are jointly, but consistently, assigned in [DiamMIP]. This document also creates one new namespace to be managed by IANA, as described in Section 11.5. This specification also specifies the use of AVPs in the 0-255 range, which are defined in [RADIUSTypes]. These values are assigned by the policy in RFC 2865 Section 6. [RADIUS] 11.3. Application Identifier This specification uses the value one (1) in the Application Identifier namespace as assigned in [Base]. See section 1.2 above for more information. 11.4. CHAP-Algorithm AVP Values As defined in Section 5.5, the CHAP-Algorithm AVP (AVP Code 403) uses the values of the "PPP AUTHENTICATION ALGORITHMS" namespace defined in [PPPCHAP]. Calhoun et al. Expires Apr 2004 [Page 69] INTERNET-DRAFT Diameter NAS Application Oct 2003 11.5. Accounting-Auth-Method AVP Values As defined in Section 8.6, the Accounting-Auth-Method AVP (AVP Code TBD) defines the values 1-5. All remaining values are available for assignment via IETF Consensus [IANA]." 12. Security Considerations The security considerations of the Diameter protocol itself have been discussed in [Base]. This document does not contain a security protocol, but does discuss how PPP authentication protocols can be carried within the Diameter protocol. The PPP authentication protocols that are described are PAP and CHAP. The use of PAP SHOULD be discouraged, since it exposes user's passwords to possibly non-trusted entities. However, PAP is also frequently used for use with One-Time Passwords (OTP), which do not expose a security risk. This document also describes how CHAP can be carried within the Diameter protocol, which is required for RADIUS backward compatibility. The CHAP protocol, as used in a RADIUS environment, facilitates authentication replay attacks. The use of the EAP authentication protocols are described in [DiamEAP] can offer better security given a method suitable for the circumstances. 13. References 13.1. Normative References [Base] P. Calhoun, et.al, "Diameter Base Protocol", RFC3588, Sept 2003. [AAATrans] B. Aboba, J. Wood. "Authentication, Authorization and Accounting (AAA) Transport Profile", draft-ietf-aaa- transport-12, IETF work in progress, January 2003 [RADIUS] C. Rigney, A. Rubens, W. Simpson, S. Willens, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000. Calhoun et al. Expires Apr 2004 [Page 70] INTERNET-DRAFT Diameter NAS Application Oct 2003 [RADIUSTypes] IANA, "RADIUS Types", URL: [RADIUSIPv6] B. Aboba, G. Zorn, D. Mitton, "RADIUS and IPv6", RFC 3162, August 2001. [IPv6Addr] Hinden, R., Deering, S., "Internet Protocol Version 6 (IPv6) Addressing Architecture", RFC 3516, April 2003. [PPPCHAP] W. Simpson, "PPP Challenge Handshake Authentication Protocol (CHAP)", RFC 1994, August 1996. [IANAConsid] Narten, Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998 [IANA] IANA Assigned Numbers Database, URL: [Keywords] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [ISOLatin] ISO 8859. International Standard -- Information Processing -- 8-bit Single-Byte Coded Graphic Character Sets -- Part 1: Latin Alphabet No. 1, ISO 8859-1:1987. URL: [ANITypes] NANPA Number Resource Info, ANI Assignments, URL: 13.2. Informative References [RADIUSAcct] C. Rigney, "RADIUS Accounting", RFC 2866, June 2000. [RADIUSExt] C. Rigney, W. Willats, P. Calhoun, "RADIUS Extensions", RFC 2869, June 2000. [RADTunnels] G. Zorn, D. Leifer, A. Rubens, J. Shriver, M. Holdrege, I. Goyret, "RADIUS Attributes for Tunnel Protocol Support", RFC 2868, June 2000. [RADTunlAcct] G. Zorn, B. Aboba, D. Mitton, "RADIUS Accounting Modifications for Tunnel Protocol Support", RFC 2867, June 2000. Calhoun et al. Expires Apr 2004 [Page 71] INTERNET-DRAFT Diameter NAS Application Oct 2003 [RADDynAuth] M. Chiba, M Dommety, M. Eklund, D. Mitton, B. Aboba, "Dynamic Authorization Extensions to Remote Authentication Dial In User Service (RADIUS)", RFC 3576, August 2003. [RADIUSIANA] B. Aboba, "IANA Considerations for RADIUS", RFC 3575, August 2003. [ExtRADPract] D. Mitton, "Network Access Servers Requirements: Extended RADIUS Practices", RFC 2882, July 2000. [NASModel] D. Mitton, M. Beadles, "Network Access Server Requirements Next Generation (NASREQNG) NAS Model", RFC 2881, July 2000. [NASCriteria] M. Beadles, D. Mitton, "Criteria for Evaluating Network Access Server Protocols", RFC 3169, September 2001. [AAACriteria] Aboba, et al., "Criteria for Evaluating AAA Protocols for Network Access", RFC 2989, Nov 2000. [DiamEAP] G. Zorn, "Diameter EAP Application", draft-ietf-aaa- eap-01.txt, IETF work in progress, August 2002. [DiamCMS] P. Calhoun, W. Bulley, S. Farrell, "Diameter CMS Security Application", draft-ietf-aaa-diameter-cms-sec-04.txt, IETF work in progress, March 2002. [DiamMIP] P. Calhoun, C. Perkins, T. Johansson, "Diameter Mobile IP Application", draft-ietf-aaa-diameter-mobileip-14.txt, IETF work in progress, April 2003. [RAD802.1X] P. Congdon, et.al "IEEE 802.1X RADIUS Usage Guidelines", RFC 3580, September 2003. [802.1X] IEEE Standard for Local and metropolitan networks - Port- Based Network Access Control, IEEE Std 802.1X-2001, June 2001 [CDMA2000] 3GPP2 "P.S0001-B", Wireless IP Network Standard, October 2002. http://www.3gpp2.com/Public_html/specs/P.S0001-B_v1.0.pdf [UTF-8] F. Yergeau, "UTF-8, a transformation format of ISO 10646", RFC 2279, January 1998. [STD51] W. Simpson, Editor, "The Point-to-Point Protocol (PPP)", STD 51, RFC 1661, July 1994 Calhoun et al. Expires Apr 2004 [Page 72] INTERNET-DRAFT Diameter NAS Application Oct 2003 14. Acknowledgements The authors would like to thank Carl Rigney, Allan C. Rubens, William Allen Simpson, and Steve Willens for their work on the original RADIUS [RADIUS], from which many of the concepts in this specification were derived. Thanks, also, to: Carl Rigney for [RADIUSAcct] and [RADIUSExt]; Ward Willats for [RADIUSExt]; Glen Zorn, Bernard Aboba and Dave Mitton for [RADTunlAcct] and [RADIPV6]; Dory Leifer, John Shriver, Matt Holdrege and Ignacio Goyret for their work on [RADTunnels]. This document stole text and concepts from both [RADTunnels] and [RADIUSExt]. Thanks go to Carl Williams for providing IPv6 specific text. The authors would also like to acknowledge the following people for their contributions in the development of the Diameter protocol: Bernard Aboba, Jari Arkko, William Bulley, Kuntal Chowdhury, Daniel C. Fox, Lol Grant, Nancy Greene, Jeff Hagg, Peter Heitman, Paul Krumviede, Fergal Ladley, Ryan Moats, Victor Muslin, Kenneth Peirce, Sumit Vakil, John R. Vollbrecht and Jeff Weisberg. Finally, Pat Calhoun would like to thank Sun Microsystems since most of the effort put into this document was done while he was in their employ. 15. Authors' Addresses Questions about this memo can be directed to: Pat R. Calhoun Airespace 110 Nortech Parkway San Jose, CA 95134 USA Phone: 1 408-635-2023 E-mail: pcalhoun@airespace.com Glen Zorn Cisco Systems, Inc. 500 108th Avenue N.E., Suite 500 Bellevue, WA 98004 USA Phone: 1 425-471-4861 E-Mail: gwz@cisco.com Calhoun et al. Expires Apr 2004 [Page 73] INTERNET-DRAFT Diameter NAS Application Oct 2003 David Spence Interlink Networks, Inc. 775 Technology Drive, Suite 200 Ann Arbor, MI 48108 USA Phone: 1 734-821-1203 Fax: 1 734-821-1235 EMail: dspence@interlinknetworks.com David Mitton Circular Logic Unlimited 733 Turnpike St #154 North Andover, MA 01845 Email: david@mitton.com Intellectual Property Considerations The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards- related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Full Copyright Statement Copyright (C) The Internet Society (2003). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it Calhoun et al. Expires Apr 2004 [Page 74] INTERNET-DRAFT Diameter NAS Application Oct 2003 or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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. Calhoun et al. Expires Apr 2004 [Page 75]