AAA Working Group Pat R. Calhoun Internet-Draft Black Storm Networks Category: Standards Track Glen Zorn Cisco Systems, Inc. David Spence Interlink Networks, Inc. David Mitton Circular Logic November 2002 Diameter NASREQ Application draft-ietf-aaa-diameter-nasreq-10.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 2002. All Rights Reserved. Abstract This document describes Diameter applications that are used for AAA in the Network Access Server (NAS) environment. This application, Calhoun et al. Expires April 2003 [Page 1] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 combined with the Diameter base protocol, Transport Profile, EAP and CMS Security specifications, satisfies NAS-related requirements defined in RFC 2989 [AAACRIT]. Given that it is expected that initial deployments of the Diameter protocol will include legacy systems. This application was carefully designed to ease the burden of protocol conversion between RADIUS and Diameter. This is achieved by re-using the RADIUS attribute space, and eliminating the need to perform many attribute translations. Calhoun et al. Expires April 2003 [Page 2] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1. Requirements Language . . . . . . . . . . . . . . . . . . . . 6 1.2. Advertising Application Support . . . . . . . . . . . . . . . 6 2. NASREQ Calls, Ports, and Sessions . . . . . . . . . . . . . . . 6 2.1. Diameter Session Establishment . . . . . . . . . . . . . . . . 7 2.2. Diameter Session Re-Authentication or Re-Authorization . . . . 7 2.3. Diameter Session Termination . . . . . . . . . . . . . . . . . 8 3. NASREQ Messages . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1. AA-Request (AAR) Command . . . . . . . . . . . . . . . . . . . 8 3.2. AA-Answer (AAA) Command . . . . . . . . . . . . . . . . . . . 11 4. NASREQ Application AVPs . . . . . . . . . . . . . . . . . . . . 13 4.1. Call and Session Information . . . . . . . . . . . . . . . . . 13 4.1.1. NAS-Port AVP . . . . . . . . . . . . . . . . . . . . . . . . 14 4.1.2. NAS-Port-Id AVP . . . . . . . . . . . . . . . . . . . . . . 14 4.1.3. NAS-Port-Type AVP . . . . . . . . . . . . . . . . . . . . . 15 4.1.4. Called-Station-Id AVP . . . . . . . . . . . . . . . . . . . 15 4.1.5. Calling-Station-Id AVP . . . . . . . . . . . . . . . . . . . 15 4.1.6. Connect-Info AVP . . . . . . . . . . . . . . . . . . . . . . 16 4.1.7. Originating-Line-Info AVP . . . . . . . . . . . . . . . . . 16 4.1.8. Reply-Message AVP . . . . . . . . . . . . . . . . . . . . . 17 4.1.9. Termination-Action AVP . . . . . . . . . . . . . . . . . . . 17 4.2. Authentication AVPs . . . . . . . . . . . . . . . . . . . . . 18 4.2.1. User-Password AVP . . . . . . . . . . . . . . . . . . . . . 19 4.2.2. Password-Retry AVP . . . . . . . . . . . . . . . . . . . . . 20 4.2.3. Prompt AVP . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.2.4. CHAP-Auth AVP . . . . . . . . . . . . . . . . . . . . . . . 20 4.2.5. CHAP-Ident AVP . . . . . . . . . . . . . . . . . . . . . . . 20 4.2.6. CHAP-Algorithm AVP . . . . . . . . . . . . . . . . . . . . . 21 4.2.7. CHAP-Challenge AVP . . . . . . . . . . . . . . . . . . . . . 21 4.2.8. CHAP-Response AVP . . . . . . . . . . . . . . . . . . . . . 21 4.2.9. ARAP-Password AVP . . . . . . . . . . . . . . . . . . . . . 21 4.2.10. ARAP-Challenge-Response AVP . . . . . . . . . . . . . . . . 21 4.2.11. ARAP-Security AVP . . . . . . . . . . . . . . . . . . . . . 22 4.2.12. ARAP-Security-Data AVP . . . . . . . . . . . . . . . . . . 22 4.3. Authorization AVPs . . . . . . . . . . . . . . . . . . . . . . 22 4.3.1. Service-Type AVP . . . . . . . . . . . . . . . . . . . . . . 23 4.3.2. Callback-Number AVP . . . . . . . . . . . . . . . . . . . . 24 4.3.3. Callback-Id AVP . . . . . . . . . . . . . . . . . . . . . . 24 4.3.4. Idle-Timeout AVP . . . . . . . . . . . . . . . . . . . . . . 25 4.3.5. Port-Limit AVP . . . . . . . . . . . . . . . . . . . . . . . 25 4.3.6. NAS-Filter-Rule AVP . . . . . . . . . . . . . . . . . . . . 25 4.3.7. Filter-Id AVP . . . . . . . . . . . . . . . . . . . . . . . 25 4.3.8. Configuration-Token AVP . . . . . . . . . . . . . . . . . . 26 4.3.9. Framed Access Authorization AVPs . . . . . . . . . . . . . . 26 4.3.9.1. Framed-Protocol AVP . . . . . . . . . . . . . . . . . . . 26 Calhoun et al. Expires April 2003 [Page 3] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.3.9.2. Framed-Routing AVP . . . . . . . . . . . . . . . . . . . . 26 4.3.9.3. Framed-MTU AVP . . . . . . . . . . . . . . . . . . . . . . 26 4.3.9.4. Framed-Compression AVP . . . . . . . . . . . . . . . . . . 27 4.3.10. IP Access . . . . . . . . . . . . . . . . . . . . . . . . . 27 4.3.10.1. Framed-IP-Address AVP . . . . . . . . . . . . . . . . . . 27 4.3.10.2. Framed-IP-Netmask AVP . . . . . . . . . . . . . . . . . . 27 4.3.10.3. Framed-Route AVP . . . . . . . . . . . . . . . . . . . . 28 4.3.10.4. Framed-Pool AVP . . . . . . . . . . . . . . . . . . . . . 28 4.3.10.5. Framed-Interface-Id AVP . . . . . . . . . . . . . . . . . 28 4.3.10.6. Framed-IPv6-Prefix AVP . . . . . . . . . . . . . . . . . 29 4.3.10.7. Framed-IPv6-Route AVP . . . . . . . . . . . . . . . . . . 29 4.3.10.8. Framed-IPv6-Pool AVP . . . . . . . . . . . . . . . . . . 29 4.3.11. IPX Access . . . . . . . . . . . . . . . . . . . . . . . . 29 4.3.11.1. Framed-IPX-Network AVP . . . . . . . . . . . . . . . . . 30 4.3.12. Appletalk Access . . . . . . . . . . . . . . . . . . . . . 30 4.3.12.1. Framed-AppleTalk-Link AVP . . . . . . . . . . . . . . . . 30 4.3.12.2. Framed-AppleTalk-Network AVP . . . . . . . . . . . . . . 30 4.3.12.3. Framed-AppleTalk-Zone AVP . . . . . . . . . . . . . . . . 31 4.3.13. ARAP Access . . . . . . . . . . . . . . . . . . . . . . . . 31 4.3.13.1. ARAP-Features AVP . . . . . . . . . . . . . . . . . . . . 31 4.3.13.2. ARAP-Zone-Access AVP . . . . . . . . . . . . . . . . . . 31 4.3.14. Non-Framed Access Authorization AVPs . . . . . . . . . . . 31 4.3.14.1. Login-IP-Host AVP . . . . . . . . . . . . . . . . . . . . 32 4.3.14.2. Login-IPv6-Host AVP . . . . . . . . . . . . . . . . . . . 32 4.3.14.3. Login-Service AVP . . . . . . . . . . . . . . . . . . . . 32 4.3.15. TCP Services . . . . . . . . . . . . . . . . . . . . . . . 32 4.3.15.1. Login-TCP-Port AVP . . . . . . . . . . . . . . . . . . . 33 4.3.16. LAT Services . . . . . . . . . . . . . . . . . . . . . . . 33 4.3.16.1. Login-LAT-Service AVP . . . . . . . . . . . . . . . . . . 33 4.3.16.2. Login-LAT-Node AVP . . . . . . . . . . . . . . . . . . . 34 4.3.16.3. Login-LAT-Group AVP . . . . . . . . . . . . . . . . . . . 34 4.3.16.4. Login-LAT-Port AVP . . . . . . . . . . . . . . . . . . . 34 4.4. Tunneling Group AVPs . . . . . . . . . . . . . . . . . . . . . 35 4.4.1. Tunnel-Type AVP . . . . . . . . . . . . . . . . . . . . . . 36 4.4.2. Tunnel-Medium-Type AVP . . . . . . . . . . . . . . . . . . . 36 4.4.3. Tunnel-Client-Endpoint AVP . . . . . . . . . . . . . . . . . 36 4.4.4. Tunnel-Server-Endpoint AVP . . . . . . . . . . . . . . . . . 37 4.4.5. Tunnel-Password AVP . . . . . . . . . . . . . . . . . . . . 38 4.4.6. Tunnel-Private-Group-Id AVP . . . . . . . . . . . . . . . . 38 4.4.7. Tunnel-Assignment-Id AVP . . . . . . . . . . . . . . . . . . 38 4.4.8. Tunnel-Preference AVP . . . . . . . . . . . . . . . . . . . 40 4.4.9. Tunnel-Client-Auth-Id AVP . . . . . . . . . . . . . . . . . 40 4.4.10. Tunnel-Server-Auth-Id AVP . . . . . . . . . . . . . . . . . 40 5. Accounting . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.1. Accounting-Input-Octets AVP . . . . . . . . . . . . . . . . . 42 5.2. Accounting-Output-Octets AVP . . . . . . . . . . . . . . . . . 42 5.3. Accounting-Input-Packets AVP . . . . . . . . . . . . . . . . . 42 5.4. Accounting-Output-Packets AVP . . . . . . . . . . . . . . . . 42 Calhoun et al. Expires April 2003 [Page 4] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 5.5. Acct-Session-Time AVP . . . . . . . . . . . . . . . . . . . . 43 5.6. Acct-Authentic AVP . . . . . . . . . . . . . . . . . . . . . . 43 5.7. Acct-Delay-Time . . . . . . . . . . . . . . . . . . . . . . . 43 5.8. Acct-Link-Count . . . . . . . . . . . . . . . . . . . . . . . 43 5.9. Acct-Tunnel-Connection AVP . . . . . . . . . . . . . . . . . . 44 5.10. Acct-Tunnel-Packets-Lost AVP . . . . . . . . . . . . . . . . 44 6. RADIUS/Diameter Protocol Interactions . . . . . . . . . . . . . 45 6.1. RADIUS Request Forwarded as Diameter Request . . . . . . . . . 45 6.1.1. Diameter Request Forwarded as RADIUS Request . . . . . . . . 47 6.2. RADIUS Attributes Used Only for Compatibility . . . . . . . . 48 6.2.1. NAS-IP-Address AVP . . . . . . . . . . . . . . . . . . . . . 49 6.2.2. NAS-IPv6-Address AVP . . . . . . . . . . . . . . . . . . . . 49 6.2.3. NAS-Identifier AVP . . . . . . . . . . . . . . . . . . . . . 49 6.2.4. State AVP . . . . . . . . . . . . . . . . . . . . . . . . . 49 6.2.5. Termination-Cause AVP Code Values . . . . . . . . . . . . . 50 6.3. RADIUS Attributes Not Allowed in Diameter Messages . . . . . . 52 6.4. Diameter AVPs that can be Translated to RADIUS Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 6.5. RADIUS Vendor Specific Attributes . . . . . . . . . . . . . . 52 6.5.1. Transmitting a Diameter Vendor AVP as a RADIUS VSA . . . . . 52 6.5.2. Forwarding a RADIUS VSA to a Diameter Vendor AVP . . . . . . 53 7. AVP Occurrence Tables . . . . . . . . . . . . . . . . . . . . . 53 7.1. AA-Request/Answer AVP Table . . . . . . . . . . . . . . . . . 54 7.2. Accounting AVP Tables . . . . . . . . . . . . . . . . . . . . 58 7.2.1. Accounting Framed Access AVP Table . . . . . . . . . . . . . 58 7.2.2. Accounting Non-Framed Access AVP Table . . . . . . . . . . . 60 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 62 8.1. Command Codes . . . . . . . . . . . . . . . . . . . . . . . . 62 8.2. AVP Codes . . . . . . . . . . . . . . . . . . . . . . . . . . 62 8.3. Application Identifier . . . . . . . . . . . . . . . . . . . . 62 8.4. CHAP-Algorithm AVP Values . . . . . . . . . . . . . . . . . . 62 9. Security Considerations . . . . . . . . . . . . . . . . . . . . 62 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 63 10.1. Normative References . . . . . . . . . . . . . . . . . . . . 63 10.2. Informative References . . . . . . . . . . . . . . . . . . . 64 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . . 66 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . . 67 Calhoun et al. Expires April 2003 [Page 5] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 1. Introduction This document describes Diameter applications that are used for AAA in the Network Access Server (NAS) environment. The Diameter NAS application, when combined with the Diameter base protocol [BASE], Transport Profile [DiamTrans] EAP [DiamEAP], and CMS Security [DiamCMS] specifications, satisfies NAS-related requirements defined in RFC2989 [AAACRIT]. Given that it is expected that initial deployments of the Diameter protocol will include legacy systems, this application was carefully designed to ease the burden of protocol conversion between RADIUS [RADIUS] and Diameter. This is achieved by re-using the RADIUS attribute space, thus eliminating the need to perform many attribute translations. This document first describes the operation of a NASREQ 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, and Accounting. The Authorization AVPs are further broken down by service type. 1.1. 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]. 1.2. Advertising Application Support Diameter nodes conforming to this specification MAY 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. NASREQ Calls, Ports, and Sessions The arrival of a new call or connection at a port of a Network Access Calhoun et al. Expires April 2003 [Page 6] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 Server (NAS) (or any NASREQ speaking device) starts a Diameter NASREQ message exchange. Information about the call, the identity of the user, and his 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. Unlike the RADIUS protocol [RADIUS], the Diameter protocol does not require authentication information to be contained in a request from the client. Therefore, it is possible to send a request for authorization only. The type of service depends upon the Auth- Request-Type AVP. This difference MAY cause operational issues in environments that need RADIUS interoperability, and it MAY be necessary that protocol conversion gateways add authentication information when transmitting to a RADIUS server. 2.1. Diameter Session Establishment When the authentication or authorization exchange completes successfully, the NASREQ application SHOULD start a session context, and MAY send an Accounting START_RECORD message [BASE]. The failure to start a session SHOULD cause an Accounting EVENT_RECORD message. 2.2. Diameter Session Re-Authentication or Re-Authorization The Diameter protocol allows for users to be periodically re- authenticated and/or re-authorized. 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 re-authentication or re-authorization via the Authorization-Lifetime AVP [BASE]. Note, however, that the Authorization-Lifetime AVP SHOULD NOT be used if the AAR message contained a NAS-IP-Address or NAS-Identifier AVP since this would mean that the NAS is using RADIUS which does not support server-initiated re-authentication or re-authorization. Calhoun et al. Expires April 2003 [Page 7] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 A NAS MUST re-authenticate and/or authorize after the period provided by the server. Furthermore, it is possible for Diameter servers to issue an unsolicited re-authentication and/or re-authorization by issuing an Re-Auth-Request message to the NAS. Upon receipt of such a message, the NAS is instructed to issue a request to re-authenticate and/or re-authorize the client. 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, SHOULD cause the sending of an Accounting STOP_RECORD message [BASE]. More information on Diameter Session Termination is in [BASE] section 8.4. 3. NASREQ 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 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, and the default mode is both authentication and authorization. Calhoun et al. Expires April 2003 [Page 8] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 identifing 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 4.3. 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. Calhoun et al. Expires April 2003 [Page 9] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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-IP-Address ] [ NAS-IPv6-Address ] [ NAS-Identifier ] [ NAS-Port-Type ] [ Port-Limit ] [ User-Name ] [ User-Password ] [ Service-Type ] [ Idle-Timeout ] [ State ] [ Authorization-Lifetime ] [ Auth-Grace-Period ] [ Auth-Session-State ] [ Session-Timeout ] [ Callback-Number ] [ Called-Station-Id ] [ Calling-Station-Id ] * [ Class ] [ Originating-Line-Info ] [ Connect-Info ] [ CHAP-Auth ] [ CHAP-Challenge ] * [ Framed-Compression ] [ Framed-Interface-Id ] * [ Framed-IPv6-Prefix ] [ Framed-IP-Address ] [ Framed-IP-Netmask ] [ Framed-MTU ] [ Framed-Protocol ] [ ARAP-Password ] [ ARAP-Security ] * [ ARAP-Security-Data ] * [ Login-IP-Host ] * [ Login-IPv6-Host ] [ Login-LAT-Group ] Calhoun et al. Expires April 2003 [Page 10] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 [ 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 4.3. 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 AVPs. If the Reply-Message AVP was present, the access device SHOULD display the text message to the user, and MUST prompt the user for a response. If the access device is unable to prompt the user for a new response, which could be achieved via PAP, it MUST treat this answer 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 ] Calhoun et al. Expires April 2003 [Page 11] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 [ Error-Reporting-Host ] [ Idle-Timeout ] [ Authorization-Lifetime ] [ Auth-Grace-Period ] [ Auth-Session-State ] [ Re-Auth-Request-Type ] [ Session-Timeout ] [ State ] * [ Reply-Message ] [ Termination-Action ] [ 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 ] * [ Framed-Compression ] [ Framed-Interface-Id ] * [ Framed-IPv6-Prefix ] [ Framed-IPv6-Pool ] * [ Framed-IPv6-Route ] [ Framed-IP-Address ] [ 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 ] Calhoun et al. Expires April 2003 [Page 12] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 * [ Redirect-Host ] [ Redirect-Host-Usage ] [ Redirect-Max-Cache-Time ] * [ Proxy-Info ] * [ AVP ] 4. NASREQ Application 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 cause interoperability issues should the request traverse a AAA node that only supports the RADIUS protocol. However, the Diameter protocol should not be hampered from future developments due to the existing installed base. There are some RADIUS attributes that are not allowed or supported directly in Diameter. See section 6 below for more information. 4.1. Call and Session Information This section contains the NASREQ unique AVPs that are needed to identify call and session context information, and allows the server to set constraints on a session. These AVPs are used in addition to the Base AVPs of: Session-Id Auth-Application-Id Origin-Host Origin-Realm Auth-Request-Type Common session status AVPs are listed here too. The following table describes the Session level AVPs, their AVP Code values, types, possible flag values and whether the AVP MAY be encrypted. Calhoun et al. Expires April 2003 [Page 13] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST|MAY | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| NAS-Port 5 4.1.1 Unsigned32 | M | P | | V | Y | NAS-Port-Id 87 4.1.2 UTF8String | M | P | | V | Y | NAS-Port-Type 61 4.1.3 Enumerated | M | P | | V | Y | Called-Station-Id 30 4.1.4 UTF8String | M | P | | V | Y | Calling-Station- 31 4.1.5 UTF8String | M | P | | V | Y | Id | | | | | | Connect-Info 77 4.1.6 UTF8String | M | P | | V | Y | Originating-Line- 94 4.1.7 OctetString| | M,P | | V | Y | Info | | | | | | Reply-Message 18 4.1.8 UTF8String | M | P | | V | Y | Termination- 29 4.1.9 Enumerated | M | P | | V | Y | Action | | | | | | -----------------------------------------|----+-----+----+-----|----| 4.1.1. 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. 4.1.2. 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. Calhoun et al. Expires April 2003 [Page 14] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.1.3. 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 services types concurrently. The supported values are defined in [RADTYPE]. 4.1.4. 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 of the phone number that the user called, using Dialed Number Identification (DNIS) or a similar technology. Note that this may be different from the phone number the call comes in on. 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. 4.1.5. 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 the ASCII string of the phone number that the call came from, using Automatic Number Identification (ANI) or a similar technology. 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 ANI. The codification of the range of allowed usage of this field is outside the scope of this specification. Calhoun et al. Expires April 2003 [Page 15] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.1.6. Connect-Info AVP The Connect-Info AVP (AVP Code 77) is of type UTF8String and is sent in the AA-Request message, and 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" 4.1.7. 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) 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 Calhoun et al. Expires April 2003 [Page 16] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 4.1.8. 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. 4.1.9. Termination-Action AVP The Termination-Action AVP is of type Enumerated and indicates what action the NAS should take when the specified service is completed. This AVP SHOULD only be present in authorization responses. The following values are supported as listed in [RADTYPE]: Calhoun et al. Expires April 2003 [Page 17] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 DEFAULT 0 Upon termination of the authorized service the NAS MUST terminate the current session. AA-REQUEST 1 Upon termination of the authorized service the NAS MAY send a new AA-Request (AAR) command. When the authorized service terminates, the NAS SHOULD NOT terminate the session or generate a Session-Termination-Request (STR) command. Instead, it SHOULD generate a new AAR command which contains the same value of the Session-Id AVP it sent in the previous AAR command. It SHOULD also include the State AVP from the previous AA-Answer (AAA) command if it contained one. An exception to this rule applies, however, if the authorized service terminates due to the expiry of the Session-Timeout AVP. In this case, the NAS MUST terminate the expired session and MAY generate a new AAR command with a new Session-Id. Note: The Termination-Action AVP is typically used for the login service (Service-Type = 1 or "Login") or by 802.1X supplicants [802.1X] (e.g., NAS-Port-Type = 19 or "Wireless - IEEE 802.11"). When used for the login service, the service typically terminates when the login host clears the connection. The NAS may prompt the user for a new connection and issue a new AA-Request. When used by 802.1X supplicants, the service typically terminates due to the expiry of the Session-Timeout AVP. The access device may then reauthenticate the user with a new AA-Request. The RECOMMENDED way to do this in Diameter is to use the Authorization-Lifetime AVP rather than the Termination-Action AVP. However, the Termination- Action AVP MAY be used when copied from a RADIUS Access-Accept to a Diameter AA-Answer by a Translation Agent. 4.2. 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]. Calhoun et al. Expires April 2003 [Page 18] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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|MAY | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| User-Password 2 4.2.1 OctetString| M | P | | V | Y | Password-Retry 75 4.2.2 Unsigned32 | M | P | | V | Y | Prompt 76 4.2.3 Enumerated | M | P | | V | Y | CHAP-Auth 409 4.2.4 Grouped | M | P | | V | Y | CHAP-Ident 410 4.2.5 OctetString| M | P | | V | Y | CHAP-Algorithm 412 4.2.6 Enumerated | M | P | | V | Y | CHAP-Challenge 60 4.2.7 OctetString| M | P | | V | Y | CHAP-Response 411 4.2.8 OctetString| M | P | | V | Y | ARAP-Password 70 4.2.9 OctetString| M | P | | V | Y | ARAP-Challenge- 84 4.2.10 OctetString| M | P | | V | Y | Response | | | | | | ARAP-Security 73 4.2.11 Unsigned32 | M | P | | V | Y | ARAP-Security- 74 4.2.12 OctetString| M | P | | V | Y | Data | | | | | | -----------------------------------------|----+-----+----+-----|----| 4.2.1. 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 [DiamSEC]. The clear-text password (prior to encryption) MUST NOT be longer than 128 bytes in length. Calhoun et al. Expires April 2003 [Page 19] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.2.2. 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 4.3.9.1) is set to ARAP. 4.2.3. 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 under "RADIUS Types" in [RADTYPE]. 4.2.4. CHAP-Auth AVP The CHAP-Auth AVP (AVP Code 409) 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 AVP containing the CHAP response depends upon the value of the CHAP-Algorithm AVP. Its Data field has the following ABNF grammar: CHAP-Auth ::= < AVP Header: 409 > { CHAP-Algorithm } { CHAP-Ident } [ CHAP-Response ] * [ AVP ] 4.2.5. CHAP-Ident AVP The CHAP-Ident AVP (AVP Code 410) is of type OctetString and contains the one octet CHAP Identifier used in the computation of the CHAP response [PPPCHAP]. Calhoun et al. Expires April 2003 [Page 20] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.2.6. CHAP-Algorithm AVP The CHAP-Algorithm AVP (AVP Code 412) is of type Enumerated and contains the algorithm identifier used in the computation of the CHAP response [PPPCHAP]. The following values are currently supported: CHAP with MD5 5 The CHAP response is computed using the procedure described in [PPPCHAP]. The CHAP-Response AVP MUST be present in the CHAP- Auth AVP. 4.2.7. CHAP-Challenge AVP The CHAP-Challenge AVP (AVP Code 60) is of type OctetString and contains the CHAP Challenge sent by the NAS to a PPP Challenge- Handshake Authentication Protocol (CHAP) [PPPCHAP] user. 4.2.8. CHAP-Response AVP The CHAP-Response AVP (AVP Code 411) is of type OctetString and contains the 16 octet authentication data provided by the user in response to the CHAP challenge [PPPCHAP]. 4.2.9. 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 4.3.9.1) 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. 4.2.10. 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 4.3.9.1) 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 password is padded at the end with NULL octets to a length of 8 before using it as a key. Calhoun et al. Expires April 2003 [Page 21] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.2.11. 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 4.3.9.1) 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. 4.2.12. 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. 4.3. Authorization AVPs in 3 This section contains the authorization AVPs that are supported in the NASREQ Application. The Service-Type AVP SHOULD be present in all messages, and based on the value of the Service-Type AVP, additional AVPs defined in this section and section 5.0 MAY be present. Due to space constraints, the short form IPFiltrRule is used to represent IPFilterRule. +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST|MAY | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| Service-Type 6 4.3.1 Enumerated | M | P | | V | Y | Callback-Number 19 4.3.2 UTF8String | M | P | | V | Y | Callback-Id 20 4.3.3 UTF8String | M | P | | V | Y | Idle-Timeout 28 4.3.4 Unsigned32 | M | P | | V | Y | Port-Limit 62 4.3.5 Unsigned32 | M | P | | V | Y | NAS-Filter-Rule 400 4.3.6 IPFiltrRule| M | P | | V | Y | Filter-Id 11 4.3.7 UTF8String | M | P | | V | Y | Configuration- 78 4.3.8 OctetString| M | | | P,V | | Token | | | | | | Calhoun et al. Expires April 2003 [Page 22] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 Framed-Protocol 7 4.3.9.1 Enumerated | M | P | | V | Y | Framed-Routing 10 4.3.9.2 Enumerated | M | P | | V | Y | Framed-MTU 12 4.3.9.3 Unsigned32 | M | P | | V | Y | Framed- 13 4.3.9.4 Enumerated | M | P | | V | Y | Compression | | | | | | Framed-IP-Address 8 4.3.10.1 IPAddress | M | P | | V | Y | Framed-IP-Netmask 9 4.3.10.2 IPAddress | M | P | | V | Y | Framed-Route 22 4.3.10.3 UTF8String | M | P | | V | Y | Framed-Pool 88 4.3.10.4 OctetString| M | P | | V | Y | Framed- 96 4.3.10.5 Unsigned64 | M | P | | V | Y | Interface-Id | | | | | | Framed-IPv6- 97 4.3.10.6 IPAddress | M | P | | V | Y | Prefix | | | | | | Framed-IPv6- 99 4.3.10.7 UTF8String | M | P | | V | Y | Route | | | | | | Framed-IPv6-Pool 100 4.3.10.8 OctetString| M | P | | V | Y | Framed-IPX- 23 4.3.11.1 UTF8String | M | P | | V | Y | Network | | | | | | Framed-Appletalk- 37 4.3.12.1 Unsigned32 | M | P | | V | Y | Link | | | | | | Framed-Appletalk- 38 4.3.12.2 Unsigned32 | M | P | | V | Y | Network | | | | | | Framed-Appletalk- 39 4.3.12.3 OctetString| M | P | | V | Y | Zone | | | | | | ARAP-Features 71 4.3.13.1 OctetString| M | P | | V | Y | ARAP-Zone-Access 72 4.3.13.2 Enumerated | M | P | | V | Y | Login-IP-Host 14 4.3.14.1 IPAddress | M | P | | V | Y | Login-IPv6-Host 98 4.3.14.2 IPAddress | M | P | | V | Y | Login-Service 15 4.3.14.3 Enumerated | M | P | | V | Y | Login-TCP-Port 16 4.3.15.1 Unsigned32 | M | P | | V | Y | Login-LAT-Service 34 4.3.16.1 OctetString| M | P | | V | Y | Login-LAT-Node 35 4.3.16.2 OctetString| M | P | | V | Y | Login-LAT-Group 36 4.3.16.3 OctetString| M | P | | V | Y | Login-LAT-Port 63 4.3.16.4 OctetString| M | P | | V | Y | -----------------------------------------|----+-----+----+-----|----| 4.3.1. 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 though a response with a Result-Code other than Diameter-SUCCESS had been received instead. Calhoun et al. Expires April 2003 [Page 23] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 would prefer the kind of service indicated, but the server is not required to honor the hint. The following values have been defined for the Service-Type AVP: The complete list of defined values can be found in [RADIUS] and [RADTYPE]. The following values are extracted from [RADIUS] and are listed here since they are further qualified: Login 1 The user should be connected to a host. The message MAY include additional AVPs defined in sections 4.3.14, 4.1.15, and 4.3.16. Framed 2 A Framed Protocol should be started for the User, such as PPP or SLIP. The message MAY include additional AVPs defined in section 4.3.9, or 4.4 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 section 4.3.9, or 4.4 for tunneling services. 4.3.2. 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. 4.3.3. 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 Calhoun et al. Expires April 2003 [Page 24] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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. 4.3.4. 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. 4.3.5. 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. 4.3.6. 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. 4.3.7. 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. Calhoun et al. Expires April 2003 [Page 25] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 In non-RADIUS environments, it is RECOMMENDED that the NAS-Filter- Rule AVP be used instead. 4.3.8. 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. 4.3.9. 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". 4.3.9.1. 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 [RADTYPE]. 4.3.9.2. 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 [RADTYPE]. 4.3.9.3. 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 Calhoun et al. Expires April 2003 [Page 26] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 between the range of 64 and 65535. 4.3.9.4. 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 [RADTYPE]. 4.3.10. 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 4.3.9.1) is set to PPP, SLIP, Gandalf proprietarySingleLink/MultiLink protocol, or X.75 Synchronous. 4.3.10.1. Framed-IP-Address AVP The Framed-IP-Address AVP (AVP Code 8) is of type IPAddress and contains the address 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 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). 4.3.10.2. Framed-IP-Netmask AVP The Framed-IP-Netmask AVP (AVP Code 9) is of type IPAddress and contains the IP 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 Calhoun et al. Expires April 2003 [Page 27] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 response. This AVP MUST be present in a response if the request included this AVP with a value of 0xFFFFFFFF. 4.3.10.3. 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 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. 4.3.10.4. 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. 4.3.10.5. 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. Calhoun et al. Expires April 2003 [Page 28] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.3.10.6. Framed-IPv6-Prefix AVP The Framed-IPv6-Prefix AVP (AVP Code 97) is of type IPAddress 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. 4.3.10.7. 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". 4.3.10.8. 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. 4.3.11. 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 4.3.9.1) is set to PPP, Xylogics proprietary IPX/SLIP, Gandalf proprietarySingleLink/MultiLink protocol, or X.75 Synchronous. Calhoun et al. Expires April 2003 [Page 29] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.3.11.1. Framed-IPX-Network AVP The Framed-IPX-Network AVP (AVP Code 23) is of type UTF8String, 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. 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). 4.3.12. 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 4.3.9.1) is set to PPP, Gandalf proprietary SingleLink/MultiLink protocol, or X.75 Synchronous. 4.3.12.1. 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. 4.3.12.2. 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 Calhoun et al. Expires April 2003 [Page 30] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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. 4.3.12.3. 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. 4.3.13. 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 4.3.9.1) is set to AppleTalk Remote Access Protocol (ARAP). 4.3.13.1. 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. 4.3.13.2. 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 [RADTYPE], and are defined in [RADIUSEXT]. 4.3.14. 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 Calhoun et al. Expires April 2003 [Page 31] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 "Login" or "Callback Login". 4.3.14.1. Login-IP-Host AVP The Login-IP-Host AVP (AVP Code 14) [RADIUS] is of type IPAddress 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: 0xFFFFFFFF and 0. The value 0xFFFFFFFF 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. 4.3.14.2. Login-IPv6-Host AVP The Login-IPv6-Host AVP (AVP Code 98) [RADIUSIPV6] is of type IPAddress 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. 4.3.14.3. 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 [RADTYPE]. 4.3.15. 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. Calhoun et al. Expires April 2003 [Page 32] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.3.15.1. 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. 4.3.16. LAT Services The AVP described in this section MAY be present if the Login-Service AVP is set to LAT. 4.3.16.1. 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). 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. Calhoun et al. Expires April 2003 [Page 33] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 4.3.16.2. 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. 4.3.16.3. 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. 4.3.16.4. 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 Calhoun et al. Expires April 2003 [Page 34] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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. 4.4. Tunneling Group AVPs The Tunneling AVP (AVP Code 403) is of type Grouped and contains AVPs used to describe a tunnel. Its Data field has the following ABNF grammar: Tunneling ::= < AVP Header: 403 > { 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 ] +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST|MAY | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| Tunneling 403 4.4 Grouped | M | P | | V | N | Tunnel-Type 64 4.4.1 Enumerated | M | P | | V | Y | Tunnel-Medium- 65 4.4.2 Enumerated | M | P | | V | Y | Type | | | | | | Tunnel-Client- 66 4.4.3 UTF8String | M | P | | V | Y | Endpoint | | | | | | Tunnel-Server- 67 4.4.4 UTF8String | M | P | | V | Y | Endpoint | | | | | | Tunnel-Password 69 4.4.5 OctetString| M | P | | V | Y | Tunnel-Private- 81 4.4.6 UTF8String | M | P | | V | Y | Group-Id | | | | | | Tunnel- 82 4.4.7 OctetString| M | P | | V | Y | Assignment-Id | | | | | | Tunnel-Preference 83 4.4.8 Unsigned32 | M | P | | V | Y | Calhoun et al. Expires April 2003 [Page 35] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 Tunnel-Client- 90 4.4.9 Unsigned32 | M | P | | V | Y | Auth-Id | | | | | | Tunnel-Server- 91 4.4.10 OctetString| M | P | | V | Y | Auth-Id | | | | | | -----------------------------------------|----+-----+----+-----|----| 4.4.1. 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 [RADTYPE]. 4.4.2. 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 Value field contains one of the values listed under "Address Family Numbers" in [IANA]. The value of most importance is (1) for IPv4 and (2) for IPv6. 4.4.3. 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 Calhoun et al. Expires April 2003 [Page 36] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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. Conformant 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. 4.4.4. 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. Conformant implementations MUST support the dotted-decimal format and SHOULD support the FQDN format for IP addresses. Calhoun et al. Expires April 2003 [Page 37] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 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. 4.4.5. 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. 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 [DiamSEC]. 4.4.6. Tunnel-Private-Group-Id AVP The Tunnel-Private-Group-Id AVP (AVP Code 81) is of type UTF8String, and contains the group Id for a particular tunneled session. The 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. 4.4.7. 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 [PPTP] and L2TP [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 Calhoun et al. Expires April 2003 [Page 38] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 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 Calhoun et al. Expires April 2003 [Page 39] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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. 4.4.8. 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 which set of AVPs to use. 4.4.9. Tunnel-Client-Auth-Id AVP The Tunnel-Client-Auth-Id AVP (AVP Code 90) is of type Unsigned32 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. 4.4.10. Tunnel-Server-Auth-Id AVP The Tunnel-Server-Auth-Id AVP (AVP Code 91) is of type OctetString and specifies the name used by the tunnel terminator during the authentication phase of tunnel establishment. It MAY be used in an Calhoun et al. Expires April 2003 [Page 40] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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. 5. Accounting Applications implementing this specification use Diameter Accounting as defined in the Base [BASE] with the addition of the AVPs in the following section. Accounting Request messages (ACR) SHOULD be sent after any Authentication or Authorization transaction or 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 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|MAY | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| Accounting- 363 5.1 Unsigned64 | M | P | | V | Y | Input-Octets | | | | | | Accounting- 364 5.2 Unsigned64 | M | P | | V | Y | Output-Octets | | | | | | Accounting- 365 5.3 Unsigned64 | M | P | | V | Y | Input-Packets | | | | | | Accounting- 366 5.4 Unsigned64 | M | P | | V | Y | Output-Packets | | | | | | Acct-Session-Time 46 5.5 Unsigned32 | M | P | | V | Y | Acct-Authentic 45 5.6 Unsigned32 | M | P | | V | Y | Acct-Delay-Time 41 5.7 Unsigned32 | M | P | | V | Y | Acct-Link-Count 51 5.8 Unsigned32 | M | P | | V | Y | Acct-Tunnel- 68 5.9 OctetString| M | P | | V | Y | Connection | | | | | | Acct-Tunnel- 86 5.10 Unsigned32 | M | P | | V | Y | Packets-Lost | | | | | | -----------------------------------------|----+-----+----+-----|----| Calhoun et al. Expires April 2003 [Page 41] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 5.1. 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 NASREQ 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. 5.2. 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. For NASREQ 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. 5.3. 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 NASREQ 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. 5.4. 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 NASREQ 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. Calhoun et al. Expires April 2003 [Page 42] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 5.5. 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. 5.6. Acct-Authentic AVP The Acct-Authentic AVP (AVP Code 45) is of type Unsigned32, and specifies how the user was authenticated. The supported values are listed in [RADTYPE]. 5.7. 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. 5.8. Acct-Link-Count The Acct-Link-Count AVP (AVP Code 51) is of type Unsigned32 and indicates the number of links which are known to have been 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 accounting server to know when it has all the records for a given multilink service. When the number of Accounting-Requests received Calhoun et al. Expires April 2003 [Page 43] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 5.9. 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. 5.10. 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 April 2003 [Page 44] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 6. RADIUS/Diameter Protocol Interactions This section describes some basic guidelines that may be used by servers that act as Translation Agents. Complete description of the differences between RADIUS and Diameter is beyond the scope of this document and section. Note that this document does not restrict implementations from creating other methods, as long as the bridging function doesn't break the RADIUS nor the Diameter protocol. +---------------------+ | AVP Flag rules | |----+-----+----+-----|----+ AVP Section | | |SHLD| MUST|MAY | Attribute Name Code Defined Value Type |MUST| MAY | NOT| NOT|Encr| -----------------------------------------|----+-----+----+-----|----| NAS-Identifier 32 6.2.3 UTF8String | M | P | | V | Y | NAS-IP-Address 4 6.2.1 IPAddress | M | P | | V | Y | NAS-IPv6-Address 95 6.2.2 IPAddress | M | P | | V | Y | State 24 6.2.4 OctetString| M | P | | V | Y | Termination- 295 6.2.5 Enumerated | M | P | | V | Y | Cause | | | | | | -----------------------------------------|----+-----+----+-----|----| 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. Note that this section uses the two terms; AVP and attribute in a consise manner. The former is used to signify a Diameter AVP, while the latter is used to signify a RADIUS attribute. 6.1. 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 assume to track session state information. Calhoun et al. Expires April 2003 [Page 45] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 When a Translation Agent receives a RADIUS message, the following steps should be taken: - If a Message-Authenticator attribute is present, it should be checked and discarded. The gateway system SHOULD generate and include a Message-Authenticator in return responses to this system. - The Diameter Origin-Host and Origin-Realm AVPs MUST be created and added using the information from the NAS-Identifier attribute, and/or the FQDN corresponding to the NAS-IP-Address attribute. 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. - 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 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 Tunnel information [RADTunnels], the attributes or tagged groups should each be converted to a Diameter Tunneling Grouped AVP set. - 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 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- Calhoun et al. Expires April 2003 [Page 46] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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, 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. 6.1.1. 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 it MAY be encoded in a RADIUS Proxy-State attribute: 1. Origin-Host AVP Calhoun et al. Expires April 2003 [Page 47] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 2. Session-Id AVP 3. Proxy-Info AVP 4. Route-Record AVPs (in the proper order) 5. 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 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. 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-Info AVP is present, extract the encoded information, otherwise retrieve the information from the local state table. - The request's Origin-Host information is added to the Destination-Host AVP. - The Acct-Session-Id information is added to the Session-Id AVP. - The Route-Record AVPs MUST be added to the Diameter message, in the same order they were present in the request. - 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, and MUST be present in the response, are added to the message. 6.2. RADIUS Attributes 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. Calhoun et al. Expires April 2003 [Page 48] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 6.2.1. NAS-IP-Address AVP The NAS-IP-Address AVP (AVP Code 4) [RADIUS] is of type IPAddress, and contains the IPv4 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. 6.2.2. NAS-IPv6-Address AVP The NAS-IPv6-Address AVP (AVP Code 95) [RADIUSIPV6] is of type IPAddress, 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. 6.2.3. 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. 6.2.4. State AVP The State AVP (AVP Code 24) [RADIUS] is of type OctetString and has two uses in the Diameter NASREQ 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 subsquent 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 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 Calhoun et al. Expires April 2003 [Page 49] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 the State AVP is implementation dependent. 6.2.5. 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 in www.iana.org, 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. +-----------------------+ | Code | +-----------+-----------+ Attribute 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 | [Congdon] Reauthentication Failure | 20 | 30 | [Congdon] Port Reinit | 21 | 31 | [Congdon] Port Disabled | 22 | 32 | [Congdon] ------------------------------|-----------+-----------+ 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. Calhoun et al. Expires April 2003 [Page 50] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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, 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. Calhoun et al. Expires April 2003 [Page 51] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 6.3. RADIUS Attributes Not Allowed in Diameter Messages The following RADIUS attributes MUST NOT be transfered to a Diameter message Many of these are discussed in section 6.1. Attribute Description Defined Nearest Diameter AVP ----------------------------------------------------------------- 3 CHAP-Password RFC 2865 CHAP-Auth Group 26 Vendor-Specific RFC 2865 Vendor Specific AVP 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 6.4. Diameter AVPs that can be Translated to RADIUS Attributes 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 (eg: Reply-Message). Some RADIUS attributes allow concatenation of multiple instances to overcome this limitation. If this is not possible, an attribute error should be returned. 6.5. 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. 6.5.1. Transmitting 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) Calhoun et al. Expires April 2003 [Page 52] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 (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" error will be returned, and the message will not be sent. 6.5.2. 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 (expanded with zeros) Diameter AVP length = length of AVP (header + data + padding) Diameter Data = RADIUS VSA vendor data 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. 7. AVP Occurrence Tables The following tables present the AVPs defined in this document, and specify in which Diameter messages they MAY, or MAY NOT be present. 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. Calhoun et al. Expires April 2003 [Page 53] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 7.1. AA-Request/Answer AVP Table The table in this section is limited to the Command Codes defined in this specification. Calhoun et al. Expires April 2003 [Page 54] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 +-----------+ | 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+ | Framed-Routing | 0 | 0-1 | Calhoun et al. Expires April 2003 [Page 55] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 ------------------------------|-----+-----+ Calhoun et al. Expires April 2003 [Page 56] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 +-----------+ | Command | |-----+-----+ Attribute Name | AAR | AAA | ------------------------------|-----+-----+ Idle-Timeout | 0-1 | 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 | 0-1 | 0-1 | State | 0-1 | 0-1 | Termination-Action | 0 | 0-1 | Termination-Cause | 0 | 0-1 | Tunneling | 0+ | 0+ | User-Name | 0-1 | 0-1 | User-Password | 0-1 | 0 | ------------------------------|-----+-----+ Calhoun et al. Expires April 2003 [Page 57] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 7.2. Accounting AVP Tables The tables in this section are used to represent which AVPs defined in this document are to be present in the Accounting messages, defined in [RADIUS]. 7.2.1. Accounting Framed Access AVP Table The table in this section is used when the Service-Type specifies Framed Access. Calhoun et al. Expires April 2003 [Page 58] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 +-----------+ | Command | | Code | |-----+-----+ Attribute Name | ACR | ACA | ---------------------------------------|-----+-----+ Accounting-Application-Id | 0-1 | 0-1 | 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 | 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 | 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 | Calhoun et al. Expires April 2003 [Page 59] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 | State | 0 | 0 | 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 | ---------------------------------------|-----+-----+ 7.2.2. 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 April 2003 [Page 60] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 +-----------+ | Command | | Code | |-----+-----+ Attribute Name | ACR | ACA | ---------------------------------------|-----+-----+ Accounting-Application-Id | 0-1 | 0-1 | Accounting-Input-Octets | 1 | 0 | Accounting-Input-Packets | 0 | 0 | Accounting-Output-Octets | 1 | 0 | Accounting-Output-Packets | 0 | 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 | 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-Filter-Rule | 0 | 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 | State | 0 | 0 | Termination-Cause | 0-1 | 0-1 | Calhoun et al. Expires April 2003 [Page 61] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 User-Name | 0-1 | 0-1 | Vendor-Specific-Application-Id | 0-1 | 0-1 | ---------------------------------------|-----+-----+ 8. IANA Considerations This section contains the namespaces that have either been created in this specification, or the values assigned to existing namespaces managed by IANA. 8.1. 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. 8.2. AVP Codes This specification assigns the values 363-366 and 400-414 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 specification also makes use of AVPs in the 0-255 range, which are defined in [RADTYPE]. 8.3. Application Identifier This specification assigns the value one (1) to the Application Identifier namespace defined in [IANAConsid]. See section 1.2 for more information. 8.4. CHAP-Algorithm AVP Values As defined in Section 4.2.6, the CHAP-Algorithm AVP (AVP Code 412) uses the values of the "PPP AUTHENTICATION ALGORITHMS" namespace defined in [PPPCHAP]. 9. Security Considerations This document does not contain any security protocol, but does discuss how PPP authentication protocols can be carried within the Calhoun et al. Expires April 2003 [Page 62] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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. PAP is also frequently used for use with One-Time Passwords (OTP), which does not expose any security risks. This document also describes how CHAP can be carried within the Diameter protocol, which is required for backward RADIUS compatibility. The CHAP protocol, as used in a RADIUS environment, facilitates authentication replay attacks. 10. References 10.1. Normative References [BASE] P. Calhoun, et.al, "Diameter Base Protocol", draft-ietf- aaa-diameter-15.txt, IETF work in progress, October 2002. [AAATrans] B. Aboba, J. Wood. "Authentication, Authorization and Accounting (AAA) Transport Profile", draft-ietf-aaa- transport-08, IETF work in progress, April 2002 [RADTYPE] IANA, "RADIUS Types", URL: [EAP] L. J. Blunk, J. R. Vollbrecht, "PPP Extensible Authentication Protocol (EAP)." RFC 2284, March 1998. [IPV6ADDR] Hinden, R., Deering, S., "IP Version 6 Addressing Architecture", RFC 2373, July 1998 [PPPCHAP] W. Simpson, "PPP Challenge Handshake Authentication Protocol (CHAP)", RFC 1994, August 1996. [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: [IANA] IANA Assigned Numbers Database, URL: Calhoun et al. Expires April 2003 [Page 63] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 [ANITYPES] NANPA Number Resource Info, ANI Assignments, URL: [KEYWORDS] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 10.2. Informative References [RADIUS] C. Rigney, A. Rubens, W. Simpson, S. Willens, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000. [RADIUSACCT] C. Rigney, "RADIUS Accounting", RFC 2866, June 2000. [RADIUSEXT] C. Rigney, W. Willats, P. Calhoun, "RADIUS Extensions", RFC 2869, June 2000. [NAI] B. Aboba, M. Beadles, "The Network Access Identifier." RFC 2486. January 1999. [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. [RADIUSIPV6] B. Aboba, G. Zorn, D. Mitton, "RADIUS and IPv6", RFC 3162, August 2001. [RADDYNAUTH] M. Chiba, M Dommety, M. Eklund, D. Mitton, B. Aboba, draft-chiba-radius-dynamic-authorization-05.txt", Work in Progress, Jan 2002 [ROAMCRIT] B. Aboba, G. Zorn, "Criteria for Evaluating Roaming Protocols", RFC 2477, January 1999. [EXTRADPRAC] 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. Calhoun et al. Expires April 2003 [Page 64] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 [NASCRIT] M. Beadles, D. Mitton, "Criteria for Evaluating Network Access Server Protocols", RFC 3169, September 2001. [AAACRIT] 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-13.txt, IETF work in progress, October 2002. [Congdon] P. Congdon, et.al "IEEE 802.1X RADIUS Usage Guidelines", draft-congdon-8021x-RADIUS-20.txt, IETF work in progress, June 2002. [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-A v3.0", Wireless IP Network Standard, July 2001. http://www.3gpp2.com/Public_html/specs/P.S0001-A_v3.0.pdf [TCPCompress] Jacobson, "Compressing TCP/IP headers for low-speed serial links", RFC 1144, February 1990. [PPPMP] Sklower, Lloyd, McGregor, Carr, "The PPP Multilink Protocol (MP)", RFC 1717, November 1994. [PPTP] Hamzeh, K., Pall, G., Verthein, W., Taarud, J., Little, W., Zorn, G., "Point-to-Point Tunneling Protocol (PPTP)", RFC 2637, July 1999 [L2F] Valencia, A., Littlewood, M., Kolar, T., "Cisco Layer Two Forwarding (Protocol) 'L2F'", RFC 2341, May 1998 [L2TP] Townsley, W. M., Valencia, A., Rubens, A., Pall, G. S., Zorn, G., Palter, B., "Layer Two Tunneling Protocol (L2TP)", RFC 2661, August 1999 [ATMP] Hamzeh, K., "Ascend Tunnel Management Protocol - ATMP", RFC 2107, February 1997 Calhoun et al. Expires April 2003 [Page 65] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 [MSMPPE] G. Pall, G. Zorn, "Microsoft Point-To-Point Encryption (MPPE) Protocol", RFC 3078, March 2001. [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 [IANAConsid] Narten, Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998 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, 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. Authors' Addresses Questions about this memo can be directed to: Pat R. Calhoun Calhoun et al. Expires April 2003 [Page 66] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 Black Storm Networks 250 Cambridge Avenue, Suite 200 Palo Alto, California, 94306 USA Phone: 1 650-617-2932 Fax: 1 650-786-6445 E-mail: pcalhoun@diameter.org 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 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 Full Copyright Statement Copyright (C) The Internet Society (2002). 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 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 Calhoun et al. Expires April 2003 [Page 67] INTERNET-DRAFT Diameter NASREQ Application Nov 2002 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 April 2003 [Page 68]