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Versions: (draft-zorn-dime-rfc4005bis) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 RFC 7155

Network Working Group                                       G. Zorn, Ed.
Internet-Draft                                               Network Zen
Obsoletes: 4005 (if approved)                               May 18, 2012
Intended status: Standards Track
Expires: November 19, 2012


               Diameter Network Access Server Application
                     draft-ietf-dime-rfc4005bis-09

Abstract

   This document describes the Diameter protocol application used for
   Authentication, Authorization, and Accounting (AAA) services in the
   Network Access Server (NAS) environment; it obsoletes RFC 4005.  When
   combined with the Diameter Base protocol, Transport Profile, and
   Extensible Authentication Protocol specifications, this application
   specification satisfies typical network access services requirements.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on November 19, 2012.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of



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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  5
     1.1.  Changes from RFC 4005  . . . . . . . . . . . . . . . . . .  5
     1.2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  6
     1.3.  Requirements Language  . . . . . . . . . . . . . . . . . .  7
     1.4.  Advertising Application Support  . . . . . . . . . . . . .  7
     1.5.  Application Identification . . . . . . . . . . . . . . . .  7
     1.6.  Accounting Model . . . . . . . . . . . . . . . . . . . . .  8
   2.  NAS Calls, Ports, and Sessions . . . . . . . . . . . . . . . .  8
     2.1.  Diameter Session Establishment . . . . . . . . . . . . . .  8
     2.2.  Diameter Session Reauthentication or Reauthorization . . .  9
     2.3.  Diameter Session Termination . . . . . . . . . . . . . . . 10
   3.  Diameter NAS Application Messages  . . . . . . . . . . . . . . 10
     3.1.  AA-Request (AAR) Command . . . . . . . . . . . . . . . . . 11
     3.2.  AA-Answer (AAA) Command  . . . . . . . . . . . . . . . . . 12
     3.3.  Re-Auth-Request (RAR) Command  . . . . . . . . . . . . . . 14
     3.4.  Re-Auth-Answer (RAA) Command . . . . . . . . . . . . . . . 15
     3.5.  Session-Termination-Request (STR) Command  . . . . . . . . 16
     3.6.  Session-Termination-Answer (STA) Command . . . . . . . . . 17
     3.7.  Abort-Session-Request (ASR) Command  . . . . . . . . . . . 18
     3.8.  Abort-Session-Answer (ASA) Command . . . . . . . . . . . . 19
     3.9.  Accounting-Request (ACR) Command . . . . . . . . . . . . . 20
     3.10. Accounting-Answer (ACA) Command  . . . . . . . . . . . . . 22
   4.  Diameter NAS Application AVPs  . . . . . . . . . . . . . . . . 23
     4.1.  Derived AVP Data Formats . . . . . . . . . . . . . . . . . 23
       4.1.1.  QoSFilterRule  . . . . . . . . . . . . . . . . . . . . 23
     4.2.  NAS Session AVPs . . . . . . . . . . . . . . . . . . . . . 24
       4.2.1.  Call and Session Information . . . . . . . . . . . . . 24
       4.2.2.  NAS-Port AVP . . . . . . . . . . . . . . . . . . . . . 25
       4.2.3.  NAS-Port-Id AVP  . . . . . . . . . . . . . . . . . . . 25
       4.2.4.  NAS-Port-Type AVP  . . . . . . . . . . . . . . . . . . 26
       4.2.5.  Called-Station-Id AVP  . . . . . . . . . . . . . . . . 26
       4.2.6.  Calling-Station-Id AVP . . . . . . . . . . . . . . . . 26
       4.2.7.  Connect-Info AVP . . . . . . . . . . . . . . . . . . . 27
       4.2.8.  Originating-Line-Info AVP  . . . . . . . . . . . . . . 27
       4.2.9.  Reply-Message AVP  . . . . . . . . . . . . . . . . . . 28
     4.3.  NAS Authentication AVPs  . . . . . . . . . . . . . . . . . 28
       4.3.1.  User-Password AVP  . . . . . . . . . . . . . . . . . . 29
       4.3.2.  Password-Retry AVP . . . . . . . . . . . . . . . . . . 29
       4.3.3.  Prompt AVP . . . . . . . . . . . . . . . . . . . . . . 29
       4.3.4.  CHAP-Auth AVP  . . . . . . . . . . . . . . . . . . . . 29
       4.3.5.  CHAP-Algorithm AVP . . . . . . . . . . . . . . . . . . 30
       4.3.6.  CHAP-Ident AVP . . . . . . . . . . . . . . . . . . . . 30
       4.3.7.  CHAP-Response AVP  . . . . . . . . . . . . . . . . . . 30



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       4.3.8.  CHAP-Challenge AVP . . . . . . . . . . . . . . . . . . 30
       4.3.9.  ARAP-Password AVP  . . . . . . . . . . . . . . . . . . 30
       4.3.10. ARAP-Challenge-Response AVP  . . . . . . . . . . . . . 30
       4.3.11. ARAP-Security AVP  . . . . . . . . . . . . . . . . . . 31
       4.3.12. ARAP-Security-Data AVP . . . . . . . . . . . . . . . . 31
     4.4.  NAS Authorization AVPs . . . . . . . . . . . . . . . . . . 31
       4.4.1.  Service-Type AVP . . . . . . . . . . . . . . . . . . . 33
       4.4.2.  Callback-Number AVP  . . . . . . . . . . . . . . . . . 33
       4.4.3.  Callback-Id AVP  . . . . . . . . . . . . . . . . . . . 34
       4.4.4.  Idle-Timeout AVP . . . . . . . . . . . . . . . . . . . 34
       4.4.5.  Port-Limit AVP . . . . . . . . . . . . . . . . . . . . 34
       4.4.6.  NAS-Filter-Rule AVP  . . . . . . . . . . . . . . . . . 34
       4.4.7.  Filter-Id AVP  . . . . . . . . . . . . . . . . . . . . 34
       4.4.8.  Configuration-Token AVP  . . . . . . . . . . . . . . . 35
       4.4.9.  QoS-Filter-Rule AVP  . . . . . . . . . . . . . . . . . 35
       4.4.10. Framed Access Authorization AVPs . . . . . . . . . . . 36
         4.4.10.1.  Framed-Protocol AVP . . . . . . . . . . . . . . . 36
         4.4.10.2.  Framed-Routing AVP  . . . . . . . . . . . . . . . 36
         4.4.10.3.  Framed-MTU AVP  . . . . . . . . . . . . . . . . . 36
         4.4.10.4.  Framed-Compression AVP  . . . . . . . . . . . . . 36
         4.4.10.5.  IP Access Authorization AVPs  . . . . . . . . . . 37
           4.4.10.5.1.  Framed-IP-Address AVP . . . . . . . . . . . . 37
           4.4.10.5.2.  Framed-IP-Netmask AVP . . . . . . . . . . . . 37
           4.4.10.5.3.  Framed-Route AVP  . . . . . . . . . . . . . . 37
           4.4.10.5.4.  Framed-Pool AVP . . . . . . . . . . . . . . . 38
           4.4.10.5.5.  Framed-Interface-Id AVP . . . . . . . . . . . 38
           4.4.10.5.6.  Framed-IPv6-Prefix AVP  . . . . . . . . . . . 38
           4.4.10.5.7.  Framed-IPv6-Route AVP . . . . . . . . . . . . 38
           4.4.10.5.8.  Framed-IPv6-Pool AVP  . . . . . . . . . . . . 39
         4.4.10.6.  IPX Access AVPs . . . . . . . . . . . . . . . . . 39
           4.4.10.6.1.  Framed-IPX-Network AVP  . . . . . . . . . . . 39
         4.4.10.7.  AppleTalk Network Access AVPs . . . . . . . . . . 39
           4.4.10.7.1.  Framed-AppleTalk-Link AVP . . . . . . . . . . 39
           4.4.10.7.2.  Framed-AppleTalk-Network AVP  . . . . . . . . 40
           4.4.10.7.3.  Framed-AppleTalk-Zone AVP . . . . . . . . . . 40
         4.4.10.8.  AppleTalk Remote Access AVPs  . . . . . . . . . . 40
           4.4.10.8.1.  ARAP-Features AVP . . . . . . . . . . . . . . 40
           4.4.10.8.2.  ARAP-Zone-Access AVP  . . . . . . . . . . . . 41
       4.4.11. Non-Framed Access Authorization AVPs . . . . . . . . . 41
         4.4.11.1.  Login-IP-Host AVP . . . . . . . . . . . . . . . . 41
         4.4.11.2.  Login-IPv6-Host AVP . . . . . . . . . . . . . . . 41
         4.4.11.3.  Login-Service AVP . . . . . . . . . . . . . . . . 42
         4.4.11.4.  TCP Services  . . . . . . . . . . . . . . . . . . 42
           4.4.11.4.1.  Login-TCP-Port AVP  . . . . . . . . . . . . . 42
         4.4.11.5.  LAT Services  . . . . . . . . . . . . . . . . . . 42
           4.4.11.5.1.  Login-LAT-Service AVP . . . . . . . . . . . . 42
           4.4.11.5.2.  Login-LAT-Node AVP  . . . . . . . . . . . . . 43
           4.4.11.5.3.  Login-LAT-Group AVP . . . . . . . . . . . . . 43



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           4.4.11.5.4.  Login-LAT-Port AVP  . . . . . . . . . . . . . 44
     4.5.  NAS Tunneling AVPs . . . . . . . . . . . . . . . . . . . . 44
       4.5.1.  Tunneling AVP  . . . . . . . . . . . . . . . . . . . . 45
       4.5.2.  Tunnel-Type AVP  . . . . . . . . . . . . . . . . . . . 45
       4.5.3.  Tunnel-Medium-Type AVP . . . . . . . . . . . . . . . . 46
       4.5.4.  Tunnel-Client-Endpoint AVP . . . . . . . . . . . . . . 46
       4.5.5.  Tunnel-Server-Endpoint AVP . . . . . . . . . . . . . . 47
       4.5.6.  Tunnel-Password AVP  . . . . . . . . . . . . . . . . . 47
       4.5.7.  Tunnel-Private-Group-Id AVP  . . . . . . . . . . . . . 47
       4.5.8.  Tunnel-Assignment-Id AVP . . . . . . . . . . . . . . . 48
       4.5.9.  Tunnel-Preference AVP  . . . . . . . . . . . . . . . . 49
       4.5.10. Tunnel-Client-Auth-Id AVP  . . . . . . . . . . . . . . 50
       4.5.11. Tunnel-Server-Auth-Id AVP  . . . . . . . . . . . . . . 50
     4.6.  NAS Accounting AVPs  . . . . . . . . . . . . . . . . . . . 50
       4.6.1.  Accounting-Input-Octets AVP  . . . . . . . . . . . . . 51
       4.6.2.  Accounting-Output-Octets AVP . . . . . . . . . . . . . 51
       4.6.3.  Accounting-Input-Packets AVP . . . . . . . . . . . . . 51
       4.6.4.  Accounting-Output-Packets AVP  . . . . . . . . . . . . 52
       4.6.5.  Acct-Session-Time AVP  . . . . . . . . . . . . . . . . 52
       4.6.6.  Acct-Authentic AVP . . . . . . . . . . . . . . . . . . 52
       4.6.7.  Accounting-Auth-Method AVP . . . . . . . . . . . . . . 52
       4.6.8.  Acct-Delay-Time AVP  . . . . . . . . . . . . . . . . . 52
       4.6.9.  Acct-Link-Count AVP  . . . . . . . . . . . . . . . . . 53
       4.6.10. Acct-Tunnel-Connection AVP . . . . . . . . . . . . . . 53
       4.6.11. Acct-Tunnel-Packets-Lost AVP . . . . . . . . . . . . . 54
   5.  AVP Occurrence Tables  . . . . . . . . . . . . . . . . . . . . 54
     5.1.  AA-Request/Answer AVP Table  . . . . . . . . . . . . . . . 54
     5.2.  Accounting AVP Tables  . . . . . . . . . . . . . . . . . . 57
       5.2.1.  Framed Access Accounting AVP Table . . . . . . . . . . 58
       5.2.2.  Non-Framed Access Accounting AVP Table . . . . . . . . 60
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 61
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 61
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 62
     8.1.  Normative References . . . . . . . . . . . . . . . . . . . 62
     8.2.  Informative References . . . . . . . . . . . . . . . . . . 63
   Appendix A.  Acknowledgements  . . . . . . . . . . . . . . . . . . 66
     A.1.  RFC 4005 . . . . . . . . . . . . . . . . . . . . . . . . . 66
     A.2.  RFC 4005bis  . . . . . . . . . . . . . . . . . . . . . . . 67













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1.  Introduction

   This document describes the Diameter protocol application used for
   AAA in the Network Access Server (NAS) environment.  When combined
   with the Diameter Base protocol [I-D.ietf-dime-rfc3588bis], Transport
   Profile [RFC3539], and EAP [RFC4072] specifications, this
   specification satisfies the NAS-related requirements defined in
   Aboba, et al. [RFC2989] and Beadles & Mitton [RFC3169].

   First, this document describes the operation of a Diameter NAS
   application.  Then it defines the Diameter message Command-Codes.
   The following sections list the AVPs used in these messages, grouped
   by common usage.  These are session identification, authentication,
   authorization, tunneling, and accounting.  The authorization AVPs are
   further broken down by service type.

1.1.  Changes from RFC 4005

   This document obsoletes RFC 4005 and is not backward compatible with
   that document.  An overview of some the major changes are given
   below.

   o  All of the material regarding RADIUS/Diameter protocol
      interactions has been removed.

   o  The Command Code Format (CCF) [I-D.ietf-dime-rfc3588bis] for the
      Accounting-Request and Accounting-Answer messages has been changed
      to explicitly require the inclusion of the Acct-Application-Id AVP
      and exclude the Vendor-Specific-Application-Id AVP.  Normally,
      this type of change would also require the allocation of a new
      command code and consequently, a new application-id (See Section
      1.3.3 of [I-D.ietf-dime-rfc3588bis]).  However, the presence of an
      instance of the Acct-Application-Id AVP was required in RFC 4005,
      as well:

         The ACR message [BASE] is sent by the NAS to report its session
         information to a target server downstream.

         Either of Acct-Application-Id or Vendor-Specific-Application-Id
         AVPs MUST be present.  If the Vendor-Specific-Application-Id
         grouped AVP is present, it must have an Acct-Application-Id
         inside.

      Thus, though the syntax of the commands has changed, the semantics
      have not (with the caveat that the Acct-Application-Id AVP can no
      longer be contained in the Vendor-Specific-Application-Id AVP).





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   o  The lists of RADIUS attribute values have been deleted in favor of
      references to the appropriate IANA registries.

   o  The accounting model to be used is now specified.

   There are many other many miscellaneous fixes that have been
   introduced in this document that may not be considered significant
   but they are useful nonetheless.  Examples are fixes to example IP
   addresses, addition of clarifying references, etc.  All of the errata
   previously filed against RFC 4005 have been fixed.  A comprehensive
   list of changes is not shown here for practical reasons.

1.2.  Terminology

   Section 1.2 of the base Diameter specification
   [I-D.ietf-dime-rfc3588bis] defines most of the terminology used in
   this document.  Additionally, the following terms and acronyms are
   used in this application:

   NAS (Network Access Server)
      A device that provides an access service for a user to a network.
      The service may be a network connection or a value-added service
      such as terminal emulation [RFC2881].

   PPP (Point-to-Point Protocol)
      A multiprotocol serial datalink.  PPP is the primary IP datalink
      used for dial-in NAS connection service [RFC1661].

   CHAP (Challenge Handshake Authentication Protocol)
      An authentication process used in PPP [RFC1994].

   PAP (Password Authentication Protocol)
      A deprecated PPP authentication process, but often used for
      backward compatibility [RFC1334].

   SLIP (Serial Line Interface Protocol)
      A serial datalink that only supports IP.  A design prior to PPP.

   ARAP (Appletalk Remote Access Protocol)
      A serial datalink for accessing Appletalk networks [ARAP].

   IPX (Internet Packet Exchange)
      The network protocol used by NetWare networks [IPX].

   L2TP (Layer Two Tunneling Protocol)

      L2TP [RFC3931] provides a dynamic mechanism for tunneling Layer 2
      "circuits" across a packet-oriented data network.



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   LAC (L2TP Access Concentrator)

      An L2TP Control Connection Endpoint being used to cross-connect an
      L2TP session directly to a data link [RFC3931].

   LAT (Local Area Transport)
      A Digital Equipment Corp.  LAN protocol for terminal services
      [LAT].

   LCP (Link Control Protocol)

      One of the three major components of PPP [RFC1661].  LCP is used
      to automatically agree upon encapsulation format options, handle
      varying limits on sizes of packets, detect a looped-back link and
      other common misconfiguration errors, and terminate the link.
      Other optional facilities provided are authentication of the
      identity of its peer on the link, and determination when a link is
      functioning properly and when it is failing.

   PPTP (Point-to-Point Tunneling Protocol)

      A protocol which allows PPP to be tunneled through an IP network
      [RFC2637].

   VPN (Virtual Private Network)
      In this document, this term is used to describe access services
      that use tunneling methods.

1.3.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

1.4.  Advertising Application Support

   Diameter nodes conforming to this specification MUST advertise
   support by including the value of one (1) in the Auth-Application-Id
   of the Capabilities-Exchange-Request (CER) message.

1.5.  Application Identification

   When used in this application, the Auth-Application-Id AVP MUST be
   set to the value one (1) in the following messages

   o  AA-Request (Section 3.1)





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   o  Re-Auth-Request(Section 3.3)

   o  Session-Termination-Request (Section 3.5)

   o  Abort-Session-Request (Section 3.7)

1.6.  Accounting Model

   It is RECOMMENDED that the coupled accounting model (Section 9.3 of
   [I-D.ietf-dime-rfc3588bis]) be used with this application; therefore,
   the value of the Acct-Application-Id AVP in the Accounting-Request
   (Section 3.10) and Accounting-Answer (Section 3.9) messages SHOULD be
   set to one (1).

2.  NAS Calls, Ports, and Sessions

   The arrival of a new call or service connection at a port of a
   Network Access Server (NAS) starts a Diameter NAS message exchange.
   Information about the call, the identity of the user, and the user's
   authentication information are packaged into a Diameter AA-Request
   (AAR) message and sent to a server.

   The server processes the information and responds with a Diameter AA-
   Answer (AAA) message that contains authorization information for the
   NAS, or a failure code (Result-Code AVP).  A value of
   DIAMETER_MULTI_ROUND_AUTH indicates an additional authentication
   exchange, and several AAR and AAA messages may be exchanged until the
   transaction completes.

   Depending on the value of the Auth-Request-Type AVP, the Diameter
   protocol allows authorization-only requests that contain no
   authentication information from the client.  This capability goes
   beyond the Call Check capabilities provided by RADIUS (Section 5.6 of
   [RFC2865]) in that no access decision is requested.  As a result,
   service cannot be started as a result of a response to an
   authorization-only request without introducing a significant security
   vulnerability.

2.1.  Diameter Session Establishment

   When the authentication or authorization exchange completes
   successfully, the NAS application SHOULD start a session context.  If
   the Result-Code of DIAMETER_MULTI_ROUND_AUTH is returned, the
   exchange continues until a success or error is returned.

   If accounting is active, the application MUST also send an Accounting
   message [I-D.ietf-dime-rfc3588bis].  An Accounting-Record-Type of
   START_RECORD is sent for a new session.  If a session fails to start,



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   the EVENT_RECORD message is sent with the reason for the failure
   described.

   Note that the return of an unsupportable Accounting-Realtime-Required
   value [I-D.ietf-dime-rfc3588bis] would result in a failure to
   establish the session.

2.2.  Diameter Session Reauthentication or Reauthorization

   The Diameter Base protocol allows users to be periodically
   reauthenticated and/or reauthorized.  In such instances, the
   Session-Id AVP in the AAR message MUST be the same as the one present
   in the original authentication/authorization message.

   A Diameter server informs the NAS of the maximum time allowed before
   reauthentication or reauthorization via the Authorization-Lifetime
   AVP [I-D.ietf-dime-rfc3588bis].  A NAS MAY reauthenticate and/or
   reauthorize before the end, but A NAS MUST reauthenticate and/or
   reauthorize at the end of the period provided by the Authorization-
   Lifetime AVP.  The failure of a reauthentication exchange will
   terminate the service.

   Furthermore, it is possible for Diameter servers to issue an
   unsolicited reauthentication and/or reauthorization request (e.g.,
   Re-Auth-Request (RAR) message [I-D.ietf-dime-rfc3588bis]) to the NAS.
   Upon receipt of such a message, the NAS MUST respond to the request
   with a Re-Auth-Answer (RAA) message [I-D.ietf-dime-rfc3588bis].

   If the RAR properly identifies an active session, the NAS will
   initiate a new local reauthentication or authorization sequence as
   indicated by the Re-Auth-Request-Type value.  This will cause the NAS
   to send a new AAR message using the existing Session-Id.  The server
   will respond with an AAA message to specify the new service
   parameters.

   If accounting is active, every change of authentication or
   authorization SHOULD generate an accounting message.  If the NAS
   service is a continuation of the prior user context, then an
   Accounting-Record-Type of INTERIM_RECORD indicating the new session
   attributes and cumulative status would be appropriate.  If a new user
   or a significant change in authorization is detected by the NAS, then
   the service may send two messages of the types STOP_RECORD and
   START_RECORD.  Accounting may change the subsession identifiers
   (Acct-Session-ID, or Acct-Sub-Session-Id) to indicate such sub-
   sessions.  A service may also use a different Session-Id value for
   accounting (see Section 9.6 of [I-D.ietf-dime-rfc3588bis]).

   However, the Diameter Session-ID AVP value used for the initial



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   authorization exchange MUST be used to generate an STR message when
   the session context is terminated.

2.3.  Diameter Session Termination

   When a NAS receives an indication that a user's session is being
   disconnected by the client (e.g., an LCP Terminate-Request message
   [RFC1661] is received) or an administrative command, the NAS MUST
   issue a Session-Termination-Request (STR) [I-D.ietf-dime-rfc3588bis]
   to its Diameter Server.  This will ensure that any resources
   maintained on the servers are freed appropriately.

   Furthermore, a NAS that receives an Abort-Session-Request (ASR)
   [I-D.ietf-dime-rfc3588bis] MUST issue an ASA if the session
   identified is active and disconnect the PPP (or tunneling) session.

   If accounting is active, an Accounting STOP_RECORD message
   [I-D.ietf-dime-rfc3588bis] MUST be sent upon termination of the
   session context.

   More information on Diameter Session Termination can be found in
   Sections 8.4 and 8.5 of [I-D.ietf-dime-rfc3588bis].

3.  Diameter NAS Application Messages

   This section defines the Diameter message Command-Code
   [I-D.ietf-dime-rfc3588bis] values that MUST be supported by all
   Diameter implementations conforming to this specification.  The
   Command Codes are as follows:

   +-----------------------------------+---------+------+--------------+
   | Command Name                      | Abbrev. | Code | Reference    |
   +-----------------------------------+---------+------+--------------+
   | AA-Request                        |   AAR   |  265 | Section 3.1  |
   | AA-Answer                         |   AAA   |  265 | Section 3.2  |
   | Re-Auth-Request                   |   RAR   |  258 | Section 3.3  |
   | Re-Auth-Answer                    |   RAA   |  258 | Section 3.4  |
   | Session-Termination-Request       |   STR   |  275 | Section 3.5  |
   | Session-Termination-Answer        |   STA   |  275 | Section 3.6  |
   | Abort-Session-Request             |   ASR   |  274 | Section 3.7  |
   | Abort-Session-Answer              |   ASA   |  274 | Section 3.8  |
   | Accounting-Request                |   ACR   |  271 | Section 3.9  |
   | Accounting-Answer                 |   ACA   |  271 | Section 3.10 |
   +-----------------------------------+---------+------+--------------+







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3.1.  AA-Request (AAR) Command

   The AA-Request (AAR), which is indicated by setting the Command-Code
   field to 265 and the 'R' bit in the Command Flags field, is used to
   request authentication and/or authorization for a given NAS user.
   The type of request is identified through the Auth-Request-Type AVP
   [I-D.ietf-dime-rfc3588bis] The recommended value for most situations
   is AUTHORIZE_AUTHENTICATE.

   If Authentication is requested, the User-Name attribute SHOULD be
   present, as well as any additional authentication AVPs that would
   carry the password information.  A request for authorization SHOULD
   only include the information from which the authorization will be
   performed, such as the User-Name, Called-Station-Id, or Calling-
   Station-Id AVPs.  All requests SHOULD contain AVPs uniquely
   identifying the source of the call, such as Origin-Host and NAS-Port.
   Certain networks MAY use different AVPs for authorization purposes.
   A request for authorization will include some AVPs defined in
   Section 4.4.

   It is possible for a single session to be authorized first and then
   for an authentication request to follow.

   This AA-Request message MAY be the result of a multi-round
   authentication exchange, which occurs when the AA-Answer message is
   received with the Result-Code AVP set to DIAMETER_MULTI_ROUND_AUTH.
   A subsequent AAR message SHOULD be sent, with the User-Password AVP
   that includes the user's response to the prompt, and MUST include any
   State AVPs that were present in the AAA message.

      Message Format

         <AA-Request> ::= < Diameter Header: 265, REQ, PXY >
                          < Session-Id >
                          { Auth-Application-Id }
                          { Origin-Host }
                          { Origin-Realm }
                          { Destination-Realm }
                          { Auth-Request-Type }
                          [ Destination-Host ]
                          [ NAS-Identifier ]
                          [ NAS-IP-Address ]
                          [ NAS-IPv6-Address ]
                          [ NAS-Port ]
                          [ NAS-Port-Id ]
                          [ NAS-Port-Type ]
                          [ Origin-AAA-Protocol ]
                          [ Origin-State-Id ]



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                          [ Port-Limit ]
                          [ User-Name ]
                          [ User-Password ]
                          [ Service-Type ]
                          [ State ]
                          [ Authorization-Lifetime ]
                          [ Auth-Grace-Period ]
                          [ Auth-Session-State ]
                          [ Callback-Number ]
                          [ Called-Station-Id ]
                          [ Calling-Station-Id ]
                          [ Originating-Line-Info ]
                          [ Connect-Info ]
                          [ CHAP-Auth ]
                          [ CHAP-Challenge ]
                        * [ Framed-Compression ]
                          [ Framed-Interface-Id ]
                          [ Framed-IP-Address ]
                        * [ Framed-IPv6-Prefix ]
                          [ Framed-IP-Netmask ]
                          [ Framed-MTU ]
                          [ Framed-Protocol ]
                          [ ARAP-Password ]
                          [ ARAP-Security ]
                        * [ ARAP-Security-Data ]
                        * [ Login-IP-Host ]
                        * [ Login-IPv6-Host ]
                          [ Login-LAT-Group ]
                          [ Login-LAT-Node ]
                          [ Login-LAT-Port ]
                          [ Login-LAT-Service ]
                        * [ Tunneling ]
                        * [ Proxy-Info ]
                        * [ Route-Record ]
                        * [ AVP ]

3.2.  AA-Answer (AAA) Command

   The AA-Answer (AAA) message is indicated by setting the Command-Code
   field to 265 and clearing the 'R' bit in the Command Flags field.  It
   is sent in response to the AA-Request (AAR) message.  If
   authorization was requested, a successful response will include the
   authorization AVPs appropriate for the service being provided, as
   defined in Section 4.4.

   For authentication exchanges requiring 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 Reply-Message or



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   more and MAY include zero or one State AVPs.

   If the Reply-Message AVP was present, the network access server
   SHOULD send the text to the user's client to display to the user,
   instructing the client to prompt the user for a response.  For
   example, this capability can be achieved in PPP via PAP.  If the
   access client is unable to prompt the user for a new response, it
   MUST treat the AA-Answer (AAA) with the Reply-Message AVP as an error
   and deny access.

      Message Format

         <AA-Answer> ::= < Diameter Header: 265, PXY >
                         < Session-Id >
                         { Auth-Application-Id }
                         { Auth-Request-Type }
                         { Result-Code }
                         { Origin-Host }
                         { Origin-Realm }
                         [ User-Name ]
                         [ Service-Type ]
                       * [ Class ]
                       * [ Configuration-Token ]
                         [ Acct-Interim-Interval ]
                         [ Error-Message ]
                         [ Error-Reporting-Host ]
                       * [ Failed-AVP ]
                         [ Idle-Timeout ]
                         [ Authorization-Lifetime ]
                         [ Auth-Grace-Period ]
                         [ Auth-Session-State ]
                         [ Re-Auth-Request-Type ]
                         [ Multi-Round-Time-Out ]
                         [ Session-Timeout ]
                         [ State ]
                       * [ Reply-Message ]
                         [ Origin-AAA-Protocol ]
                         [ 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 ]



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                         [ Callback-Number ]
                         [ Framed-Appletalk-Link ]
                       * [ Framed-Appletalk-Network ]
                         [ Framed-Appletalk-Zone ]
                       * [ Framed-Compression ]
                         [ Framed-Interface-Id ]
                         [ Framed-IP-Address ]
                       * [ Framed-IPv6-Prefix ]
                         [ Framed-IPv6-Pool ]
                       * [ Framed-IPv6-Route ]
                         [ Framed-IP-Netmask ]
                       * [ Framed-Route ]
                         [ Framed-Pool ]
                         [ Framed-IPX-Network ]
                         [ Framed-MTU ]
                         [ Framed-Protocol ]
                         [ Framed-Routing ]
                       * [ Login-IP-Host ]
                       * [ Login-IPv6-Host ]
                         [ Login-LAT-Group ]
                         [ Login-LAT-Node ]
                         [ Login-LAT-Port ]
                         [ Login-LAT-Service ]
                         [ Login-Service ]
                         [ Login-TCP-Port ]
                       * [ NAS-Filter-Rule ]
                       * [ QoS-Filter-Rule ]
                       * [ Tunneling ]
                       * [ Redirect-Host ]
                         [ Redirect-Host-Usage ]
                         [ Redirect-Max-Cache-Time ]
                       * [ Proxy-Info ]
                       * [ AVP ]

3.3.  Re-Auth-Request (RAR) Command

   A Diameter server may initiate a re-authentication and/or re-
   authorization service for a particular session by issuing a Re-Auth-
   Request (RAR) message [I-D.ietf-dime-rfc3588bis].

   For example, for pre-paid services, the Diameter server that
   originally authorized a session may need some confirmation that the
   user is still using the services.

   If a NAS receives an RAR message with Session-Id equal to a currently
   active session and a Re-Auth-Type that includes authentication, it
   MUST initiate a re-authentication toward the user, if the service
   supports this particular feature.



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      Message Format

         <RA-Request>  ::= < Diameter Header: 258, REQ, PXY >
                          < Session-Id >
                          { Origin-Host }
                          { Origin-Realm }
                          { Destination-Realm }
                          { Destination-Host }
                          { Auth-Application-Id }
                          { Re-Auth-Request-Type }
                          [ User-Name ]
                          [ Origin-AAA-Protocol ]
                          [ Origin-State-Id ]
                          [ NAS-Identifier ]
                          [ NAS-IP-Address ]
                          [ NAS-IPv6-Address ]
                          [ NAS-Port ]
                          [ NAS-Port-Id ]
                          [ NAS-Port-Type ]
                          [ Service-Type ]
                          [ Framed-IP-Address ]
                          [ Framed-IPv6-Prefix ]
                          [ Framed-Interface-Id ]
                          [ Called-Station-Id ]
                          [ Calling-Station-Id ]
                          [ Originating-Line-Info ]
                          [ Acct-Session-Id ]
                          [ Acct-Multi-Session-Id ]
                          [ State ]
                        * [ Class ]
                          [ Reply-Message ]
                        * [ Proxy-Info ]
                        * [ Route-Record ]
                        * [ AVP ]

3.4.  Re-Auth-Answer (RAA) Command

   The Re-Auth-Answer (RAA) message [I-D.ietf-dime-rfc3588bis] is sent
   in response to the RAR.  The Result-Code AVP MUST be present and
   indicates the disposition of the request.

   A successful RAA transaction MUST be followed by an AAR message.









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      Message Format

         <RA-Answer>  ::= < Diameter Header: 258, PXY >
                          < Session-Id >
                          { Result-Code }
                          { Origin-Host }
                          { Origin-Realm }
                          [ User-Name ]
                          [ Origin-AAA-Protocol ]
                          [ Origin-State-Id ]
                          [ Error-Message ]
                          [ Error-Reporting-Host ]
                        * [ Failed-AVP ]
                        * [ Redirected-Host ]
                          [ Redirected-Host-Usage ]
                          [ Redirected-Host-Cache-Time ]
                          [ Service-Type ]
                        * [ Configuration-Token ]
                          [ Idle-Timeout ]
                          [ Authorization-Lifetime ]
                          [ Auth-Grace-Period ]
                          [ Re-Auth-Request-Type ]
                          [ State ]
                        * [ Class ]
                        * [ Reply-Message ]
                          [ Prompt ]
                        * [ Proxy-Info ]
                        * [ AVP ]

3.5.  Session-Termination-Request (STR) Command

   The Session-Termination-Request (STR) message
   [I-D.ietf-dime-rfc3588bis] is sent by the NAS to inform the Diameter
   Server that an authenticated and/or authorized session is being
   terminated.
















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      Message Format

         <ST-Request> ::= < Diameter Header: 275, REQ, PXY >
                         < Session-Id >
                         { Origin-Host }
                         { Origin-Realm }
                         { Destination-Realm }
                         { Auth-Application-Id }
                         { Termination-Cause }
                         [ User-Name ]
                         [ Destination-Host ]
                       * [ Class ]
                         [ Origin-AAA-Protocol ]
                         [ Origin-State-Id ]
                       * [ Proxy-Info ]
                       * [ Route-Record ]
                       * [ AVP ]

3.6.  Session-Termination-Answer (STA) Command

   The Session-Termination-Answer (STA) message
   [I-D.ietf-dime-rfc3588bis] is sent by the Diameter Server to
   acknowledge the notification that the session has been terminated.
   The Result-Code AVP MUST be present and MAY contain an indication
   that an error occurred while the STR was being serviced.

   Upon sending or receiving the STA, the Diameter Server MUST release
   all resources for the session indicated by the Session-Id AVP.  Any
   intermediate server in the Proxy-Chain MAY also release any
   resources, if necessary.





















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      Message Format

         <ST-Answer>  ::= < Diameter Header: 275, PXY >
                          < Session-Id >
                          { Result-Code }
                          { Origin-Host }
                          { Origin-Realm }
                          [ User-Name ]
                        * [ Class ]
                          [ Error-Message ]
                          [ Error-Reporting-Host ]
                        * [ Failed-AVP ]
                          [ Origin-AAA-Protocol ]
                          [ Origin-State-Id ]
                        * [ Redirect-Host ]
                          [ Redirect-Host-Usase ]
                          [ Redirect-Max-Cache-Time ]
                        * [ Proxy-Info ]
                        * [ AVP ]

3.7.  Abort-Session-Request (ASR) Command

   The Abort-Session-Request (ASR) message [I-D.ietf-dime-rfc3588bis]
   may be sent by any server to the NAS providing session service, to
   request that the session identified by the Session-Id be stopped.


























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      Message Format

         <AS-Request>  ::= < Diameter Header: 274, REQ, PXY >
                          < Session-Id >
                          { Origin-Host }
                          { Origin-Realm }
                          { Destination-Realm }
                          { Destination-Host }
                          { Auth-Application-Id }
                          [ User-Name ]
                          [ Origin-AAA-Protocol ]
                          [ Origin-State-Id ]
                          [ NAS-Identifier ]
                          [ NAS-IP-Address ]
                          [ NAS-IPv6-Address ]
                          [ NAS-Port ]
                          [ NAS-Port-Id ]
                          [ NAS-Port-Type ]
                          [ Service-Type ]
                          [ Framed-IP-Address ]
                          [ Framed-IPv6-Prefix ]
                          [ Framed-Interface-Id ]
                          [ Called-Station-Id ]
                          [ Calling-Station-Id ]
                          [ Originating-Line-Info ]
                          [ Acct-Session-Id ]
                          [ Acct-Multi-Session-Id ]
                          [ State ]
                        * [ Class ]
                        * [ Reply-Message ]
                        * [ Proxy-Info ]
                        * [ Route-Record ]
                        * [ AVP ]

3.8.  Abort-Session-Answer (ASA) Command

   The ASA message [I-D.ietf-dime-rfc3588bis] is sent in response to the
   ASR.  The Result-Code AVP MUST be present and indicates the
   disposition of the request.

   If the session identified by Session-Id in the ASR was successfully
   terminated, Result-Code is set to DIAMETER_SUCCESS.  If the session
   is not currently active, the Result-Code AVP is set to
   DIAMETER_UNKNOWN_SESSION_ID.  If the access device does not stop the
   session for any other reason, the Result-Code AVP is set to
   DIAMETER_UNABLE_TO_COMPLY.





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      Message Format

         <AS-Answer>  ::= < Diameter Header: 274, PXY >
                          < Session-Id >
                          { Result-Code }
                          { Origin-Host }
                          { Origin-Realm }
                          [ User-Name ]
                          [ Origin-AAA-Protocol ]
                          [ Origin-State-Id ]
                          [ State]
                          [ Error-Message ]
                          [ Error-Reporting-Host ]
                        * [ Failed-AVP ]
                        * [ Redirected-Host ]
                          [ Redirected-Host-Usage ]
                          [ Redirected-Max-Cache-Time ]
                        * [ Proxy-Info ]
                        * [ AVP ]

3.9.  Accounting-Request (ACR) Command

   The ACR message [I-D.ietf-dime-rfc3588bis] is sent by the NAS to
   report its session information to a target server downstream.

   The Acct-Application-Id AVP MUST be present.

   The AVPs listed in the Base protocol specification
   [I-D.ietf-dime-rfc3588bis] MUST be assumed to be present, as
   appropriate.  NAS service-specific accounting AVPs SHOULD be present
   as described in Section 4.6 and the rest of this specification.

      Message Format

         <AC-Request> ::= < Diameter Header: 271, REQ, PXY >
                         < Session-Id >
                         { Origin-Host }
                         { Origin-Realm }
                         { Destination-Realm }
                         { Accounting-Record-Type }
                         { Accounting-Record-Number }
                         { Acct-Application-Id }
                         [ User-Name ]
                         [ Accounting-Sub-Session-Id ]
                         [ Acct-Session-Id ]
                         [ Acct-Multi-Session-Id ]
                         [ Origin-AAA-Protocol ]
                         [ Origin-State-Id ]



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                         [ Destination-Host ]
                         [ Event-Timestamp ]
                         [ Acct-Delay-Time ]
                         [ NAS-Identifier ]
                         [ NAS-IP-Address ]
                         [ NAS-IPv6-Address ]
                         [ NAS-Port ]
                         [ NAS-Port-Id ]
                         [ NAS-Port-Type ]
                       * [ Class ]
                         [ Service-Type ]
                         [ Termination-Cause ]
                         [ Accounting-Input-Octets ]
                         [ Accounting-Input-Packets ]
                         [ Accounting-Output-Octets ]
                         [ Accounting-Output-Packets ]
                         [ Acct-Authentic ]
                         [ Accounting-Auth-Method ]
                         [ Acct-Link-Count ]
                         [ Acct-Session-Time ]
                         [ Acct-Tunnel-Connection ]
                         [ Acct-Tunnel-Packets-Lost ]
                         [ Callback-Id ]
                         [ Callback-Number ]
                         [ Called-Station-Id ]
                         [ Calling-Station-Id ]
                       * [ Connection-Info ]
                         [ Originating-Line-Info ]
                         [ Authorization-Lifetime ]
                         [ Session-Timeout ]
                         [ Idle-Timeout ]
                         [ Port-Limit ]
                         [ Accounting-Realtime-Required ]
                         [ Acct-Interim-Interval ]
                       * [ Filter-Id ]
                       * [ NAS-Filter-Rule ]
                       * [ Qos-Filter-Rule ]
                         [ Framed-AppleTalk-Link ]
                         [ Framed-AppleTalk-Network ]
                         [ Framed-AppleTalk-Zone ]
                         [ Framed-Compression ]
                         [ Framed-Interface-Id ]
                         [ Framed-IP-Address ]
                         [ Framed-IP-Netmask ]
                       * [ Framed-IPv6-Prefix ]
                         [ Framed-IPv6-Pool ]
                       * [ Framed-IPv6-Route ]
                         [ Framed-IPX-Network ]



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                         [ Framed-MTU ]
                         [ Framed-Pool ]
                         [ Framed-Protocol ]
                       * [ Framed-Route ]
                         [ 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 ]
                       * [ Tunneling ]
                       * [ Proxy-Info ]
                       * [ Route-Record ]
                       * [ AVP ]

3.10.  Accounting-Answer (ACA) Command

   The ACA message [I-D.ietf-dime-rfc3588bis] is used to acknowledge an
   Accounting-Request command.  The Accounting-Answer command contains
   the same Session-Id as the Request.  The same level of security MUST
   be applied to both the Accounting-Request and the corresponding
   Accounting-Answer message.  For example, if the ACR was protected
   using end-to-end security techniques then the corresponding ACA
   message MUST be protected in the same way; note, however, that the
   definition of such techniques is outside the scope of this document.

   Only the target Diameter Server or home Diameter Server SHOULD
   respond with the Accounting-Answer command.

   The Acct-Application-Id AVP MUST be present.

   The AVPs listed in the Base protocol specification
   [I-D.ietf-dime-rfc3588bis] MUST be assumed to be present, as
   appropriate.  NAS service-specific accounting AVPs SHOULD be present
   as described in Section 4.6 and the rest of this specification.













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      Message Format

         <AC-Answer> ::= < Diameter Header: 271, PXY >
                         < Session-Id >
                         { Result-Code }
                         { Origin-Host }
                         { Origin-Realm }
                         { Accounting-Record-Type }
                         { Accounting-Record-Number }
                         { Acct-Application-Id }
                         [ User-Name ]
                         [ Accounting-Sub-Session-Id ]
                         [ Acct-Session-Id ]
                         [ Acct-Multi-Session-Id ]
                         [ Event-Timestamp ]
                         [ Error-Message ]
                         [ Error-Reporting-Host ]
                       * [ Failed-AVP ]
                         [ Origin-AAA-Protocol ]
                         [ Origin-State-Id ]
                         [ NAS-Identifier ]
                         [ NAS-IP-Address ]
                         [ NAS-IPv6-Address ]
                         [ NAS-Port ]
                         [ NAS-Port-Id ]
                         [ NAS-Port-Type ]
                         [ Service-Type ]
                         [ Termination-Cause ]
                         [ Accounting-Realtime-Required ]
                         [ Acct-Interim-Interval ]
                       * [ Class ]
                       * [ Proxy-Info ]
                       * [ AVP ]

4.  Diameter NAS Application AVPs

   The following sections define a new derived AVP data format, a set of
   application-specific AVPs and describe the use of AVPs defined in
   other documents by the Diameter NAS Application.

4.1.  Derived AVP Data Formats

4.1.1.  QoSFilterRule

   The QosFilterRule format is derived from the OctetString AVP Base
   Format.  It uses the ASCII charset.  Packets may be marked or metered
   based on the following information:




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   o  Direction (in or out)

   o  Source and destination IP address (possibly masked)

   o  Protocol

   o  Source and destination port (lists or ranges)

   o  DSCP values (no mask or range)

   Rules for the appropriate direction are evaluated in order; the first
   matched rule terminates the evaluation.  Each packet is evaluated
   once.  If no rule matches, the packet is treated as best effort.  An
   access device unable to interpret or apply a QoS rule SHOULD NOT
   terminate the session.

   QoSFilterRule filters MUST follow the following format:

      action dir proto from src to dst [options]
      where

      action
                  tag         Mark packet with a specific DSCP [RFC2474]
                  meter       Meter traffic

      dir         The format is as described under IPFilterRule
                  [I-D.ietf-dime-rfc3588bis]

      proto       The format is as described under IPFilterRule
                  [I-D.ietf-dime-rfc3588bis]

      src and dst The format is as described under IPFilterRule
                  [I-D.ietf-dime-rfc3588bis]

   The options are described in Section 4.4.9.

   The rule syntax is a modified subset of ipfw(8) from FreeBSD, and the
   ipfw.c code may provide a useful base for implementations.

4.2.  NAS Session AVPs

   Diameter reserves the AVP Codes 0 - 255 for RADIUS Attributes that
   are implemented in Diameter.

4.2.1.  Call and Session Information

   This section describes the AVPs specific to Diameter applications
   that are needed to identify the call and session context and status



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   information.  On a request, this information allows the server to
   qualify the session.

   These AVPs are used in addition to the following AVPs from the base
   protocol specification [I-D.ietf-dime-rfc3588bis]:

      Session-Id
      Auth-Application-Id
      Origin-Host
      Origin-Realm
      Auth-Request-Type
      Termination-Cause

   The following table gives the possible flag values for the session
   level AVPs.

                                                    +----------+
                                                    | AVP Flag |
                                                    |   rules  |
                                                    |----+-----+
                                                    |MUST| MUST|
           Attribute Name          Section Defined  |    |  NOT|
           -----------------------------------------|----+-----|
           NAS-Port                4.2.2            | M  |  V  |
           NAS-Port-Id             4.2.3            | M  |  V  |
           NAS-Port-Type           4.2.4            | M  |  V  |
           Called-Station-Id       4.2.5            | M  |  V  |
           Calling-Station-Id      4.2.6            | M  |  V  |
           Connect-Info            4.2.7            | M  |  V  |
           Originating-Line-Info   4.2.8            | M  |  V  |
           Reply-Message           4.2.9            | M  |  V  |
           -----------------------------------------|----+-----|

4.2.2.  NAS-Port AVP

   The NAS-Port AVP (AVP Code 5) is of type Unsigned32 and contains the
   physical or virtual port number of the NAS which is authenticating
   the user.  Note that "port" is meant in its sense as a service
   connection on the NAS, not as an IP protocol identifier.

   Either the NAS-Port AVP or the NAS-Port-Id AVP (Section 4.2.3) SHOULD
   be present in the AA-Request (AAR, Section 3.1) command if the NAS
   differentiates among its ports.

4.2.3.  NAS-Port-Id AVP

   The NAS-Port-Id AVP (AVP Code 87) is of type UTF8String and consists
   of ASCII text identifying the port of the NAS authenticating the



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   user.  Note that "port" is meant in its sense as a service connection
   on the NAS, not as an IP protocol identifier.

   Either the NAS-Port-Id AVP or the NAS-Port AVP (Section 4.2.2) SHOULD
   be present in the AA-Request (AAR, Section 3.1) command if the NAS
   differentiates among its ports.  NAS-Port-Id is intended for use by
   NASes that cannot conveniently number their ports.

4.2.4.  NAS-Port-Type AVP

   The NAS-Port-Type AVP (AVP Code 61) is of type Enumerated and
   contains the type of the port on which the NAS is authenticating the
   user.  This AVP SHOULD be present if the NAS uses the same NAS-Port
   number ranges for different service types concurrently.

   The currently supported values of the NAS-Port-Type AVP are listed in
   [RADIUSTypes].

4.2.5.  Called-Station-Id AVP

   The Called-Station-Id AVP (AVP Code 30) is of type UTF8String and
   allows the NAS to send the ASCII string describing the Layer 2
   address the user contacted in the request.  For dialup access, this
   can be a phone number obtained by using the Dialed Number
   Identification Service (DNIS) or a similar technology.  Note that
   this may be different from the phone number the call comes in on.
   For use with IEEE 802 access, the Called-Station-Id MAY contain a MAC
   address formatted as described in Congdon, et al. [RFC3580].

   If the Called-Station-Id AVP is present in an AAR message, Auth-
   Request-Type AVP is set to AUTHORIZE_ONLY and the User-Name AVP is
   absent, the Diameter Server MAY perform authorization based on this
   AVP.  This can be used by a NAS to request whether a call should be
   answered based on the DNIS result.

   The codification of this field's allowed usage range is outside the
   scope of this specification.

4.2.6.  Calling-Station-Id AVP

   The Calling-Station-Id AVP (AVP Code 31) is of type UTF8String and
   allows the NAS to send the ASCII string describing the Layer 2
   address from which the user connected in the request.  For dialup
   access, this is the phone number the call came from, using Automatic
   Number Identification (ANI) or a similar technology.  For use with
   IEEE 802 access, the Calling-Station-Id AVP MAY contain a MAC
   address, formated as described in RFC 3580.




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   If the Calling-Station-Id AVP is present in an AAR message, the Auth-
   Request-Type AVP is set to AUTHORIZE_ONLY and the User-Name AVP is
   absent, the Diameter Server MAY perform authorization based on the
   value of this AVP.  This can be used by a NAS to request whether a
   call should be answered based on the Layer 2 address (ANI, MAC
   Address, etc.)

   The codification of this field's allowed usage range is outside the
   scope of this specification.

4.2.7.  Connect-Info AVP

   The Connect-Info AVP (AVP Code 77) is of type UTF8String and is sent
   in the AA-Request message or an ACR message with the value of the
   Accounting-Record-Type AVP set to STOP.  When sent in the AA-Request,
   it indicates the nature of the user's connection.  The connection
   speed SHOULD be included at the beginning of the first Connect-Info
   AVP in the message.  If the transmit and receive connection speeds
   differ, both may be included in the first AVP with the transmit speed
   listed first (the speed at which the NAS modem transmits), then a
   slash (/), then the receive speed, and then other optional
   information.

   For example: "28800 V42BIS/LAPM" or "52000/31200 V90"

   If sent in an ACR message with the value of the Accounting-Record-
   Type AVP set to STOP, this attribute may summarize statistics
   relating to session quality.  For example, in IEEE 802.11, the
   Connect-Info AVP may contain information on the number of link layer
   retransmissions.  The exact format of this attribute is
   implementation specific.

4.2.8.  Originating-Line-Info AVP

   The Originating-Line-Info AVP (AVP Code 94) is of type OctetString
   and is sent by the NAS system to convey information about the origin
   of the call from an SS7 system.

   The Originating Line Information (OLI) element indicates the nature
   and/or characteristics of the line from which a call originated
   (e.g., pay phone, 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 to define different services.

   The Value field contains two octets (00 - 99).  ANSI T1.113 and
   BELLCORE 394 can be used for additional information about these



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   values and their use.  For information on the currently assigned
   values, see [ANITypes].

4.2.9.  Reply-Message AVP

   The Reply-Message AVP (AVP Code 18) is of type UTF8String and
   contains text that MAY be displayed to the user.  When used in an AA-
   Answer message with a successful Result-Code AVP, it indicates
   success.  When found in an AAA message with a Result-Code other than
   DIAMETER_SUCCESS, the AVP contains a failure message.

   The Reply-Message AVP MAY contain text to prompt the user before
   another AA-Request attempt.  When used in an AA-Answer message
   containing a Result-Code AVP with the value DIAMETER_MULTI_ROUND_AUTH
   or in an Re-Auth-Request message, it MAY contain text to prompt the
   user for a response.

4.3.  NAS Authentication AVPs

   This section defines the AVPs necessary to carry the authentication
   information in the Diameter protocol.  The functionality defined here
   provides a RADIUS-like AAA service [RFC2865] over a more reliable and
   secure transport, as defined in the base protocol
   [I-D.ietf-dime-rfc3588bis].

   The following table gives the possible flag values for the session
   level AVPs.

                                                    +----------+
                                                    | AVP Flag |
                                                    |  rules   |
                                                    |----+-----|
                                                    |MUST| MUST|
           Attribute Name           Section Defined |    |  NOT|
           -----------------------------------------|----+-----|
           User-Password                 4.3.1      | M  |  V  |
           Password-Retry                4.3.2      | M  |  V  |
           Prompt                        4.3.3      | M  |  V  |
           CHAP-Auth                     4.3.4      | M  |  V  |
           CHAP-Algorithm                4.3.5      | M  |  V  |
           CHAP-Ident                    4.3.6      | M  |  V  |
           CHAP-Response                 4.3.7      | M  |  V  |
           CHAP-Challenge                4.3.8      | M  |  V  |
           ARAP-Password                 4.3.9      | M  |  V  |
           ARAP-Challenge-Response       4.3.10     | M  |  V  |
           ARAP-Security                 4.3.11     | M  |  V  |
           ARAP-Security-Data            4.3.12     | M  |  V  |
           -----------------------------------------|----+-----|



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4.3.1.  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 by
   Fajardo, et al. [I-D.ietf-dime-rfc3588bis], Diameter messages are
   encrypted by using IPsec [RFC4301] or TLS [RFC5246].  Unless this AVP
   is used for one-time passwords, the User-Password AVP SHOULD NOT be
   used in untrusted proxy environments without encrypting it by using
   end-to-end security techniques.

   The clear-text password (prior to encryption) MUST NOT be longer than
   128 bytes in length.

4.3.2.  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 is permitted before being
   disconnected.  This AVP is primarily intended for use when the
   Framed-Protocol AVP (Section 4.4.10.1) is set to ARAP.

4.3.3.  Prompt AVP

   The Prompt AVP (AVP Code 76) is of type Enumerated and MAY be present
   in the AA-Answer message.  When present, it is used by the NAS to
   determine whether the user's response, when entered, should be
   echoed.

   The supported values are listed in [RADIUSTypes]

4.3.4.  CHAP-Auth AVP

   The CHAP-Auth AVP (AVP Code 402) is of type Grouped and contains the
   information necessary to authenticate a user using the PPP Challenge-
   Handshake Authentication Protocol (CHAP) [RFC1994].  If the CHAP-Auth
   AVP is found in a message, the CHAP-Challenge AVP (Section 4.3.8)
   MUST be present as well.  The optional AVPs containing the CHAP
   response depend upon the value of the CHAP-Algorithm AVP
   (Section 4.3.8).  The grouped AVP has the following ABNF grammar:







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   CHAP-Auth  ::= < AVP Header: 402 >
                  { CHAP-Algorithm }
                  { CHAP-Ident }
                  [ CHAP-Response ]
                * [ AVP ]

4.3.5.  CHAP-Algorithm AVP

   The CHAP-Algorithm AVP (AVP Code 403) is of type Enumerated and
   contains the algorithm identifier used in the computation of the CHAP
   response [RFC1994].  The following values are currently supported:

   CHAP with MD5 5  The CHAP response is computed by using the procedure
      described in [RFC1994] This algorithm requires that the CHAP-
      Response AVP (Section 4.3.7) MUST be present in the CHAP-Auth AVP
      (Section 4.3.4).

4.3.6.  CHAP-Ident AVP

   The CHAP-Ident AVP (AVP Code 404) is of type OctetString and contains
   the 1 octet CHAP Identifier used in the computation of the CHAP
   response [RFC1994]

4.3.7.  CHAP-Response AVP

   The CHAP-Response AVP (AVP Code 405) is of type OctetString and
   contains the 16 octet authentication data provided by the user in
   response to the CHAP challenge [RFC1994].

4.3.8.  CHAP-Challenge AVP

   The CHAP-Challenge AVP (AVP Code 60) is of type OctetString and
   contains the CHAP Challenge sent by the NAS to the CHAP peer
   [RFC1994].

4.3.9.  ARAP-Password AVP

   The ARAP-Password AVP (AVP Code 70) is of type OctetString and is
   only present when the Framed-Protocol AVP (Section 4.4.10.1) 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 Rigney, et al. [RFC2869] for more information on the contents of
   this AVP.

4.3.10.  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 (Section 4.4.10.1)



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   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 Diameter
   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 fewer than 8 octets in length,
   the password is padded at the end with NULL octets to a length of 8
   before it is used as a key.

4.3.11.  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
   (Section 4.4.10.1) is set to the value of ARAP, and the Result-Code
   AVP ([I-D.ietf-dime-rfc3588bis], Section 7.1) is set to
   DIAMETER_MULTI_ROUND_AUTH.  See RFC 2869 for more information on the
   contents of this AVP.

4.3.12.  ARAP-Security-Data AVP

   The ARAP-Security-Data 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 (Section 4.4.10.1) is set to the value of ARAP and the
   Result-Code AVP ([I-D.ietf-dime-rfc3588bis], Section 7.1) is set to
   DIAMETER_MULTI_ROUND_AUTH.  This AVP contains the security module
   challenge or response associated with the ARAP Security Module
   specified in the ARAP-Security AVP (Section 4.3.11).

4.4.  NAS Authorization AVPs

   This section contains the authorization AVPs supported in the NAS
   Application.  The Service-Type AVP SHOULD be present in all messages
   and, based on its value, additional AVPs defined in this section and
   Section 4.5 MAY be present.

   The following table gives the possible flag values for the session-
   level AVPs.














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                                                    +----------+
                                                    | AVP Flag |
                                                    |  rules   |
                                                    |----+-----|
                                                    |MUST| MUST|
           Attribute Name           Section Defined |    |  NOT|
           -----------------------------------------|----+-----|
           Service-Type                4.4.1        | M  |  V  |
           Callback-Number             4.4.2        | M  |  V  |
           Callback-Id                 4.4.3        | M  |  V  |
           Idle-Timeout                4.4.4        | M  |  V  |
           Port-Limit                  4.4.5        | M  |  V  |
           NAS-Filter-Rule             4.4.6        | M  |  V  |
           Filter-Id                   4.4.7        | M  |  V  |
           Configuration-Token         4.4.8        | M  |  V  |
           QoS-Filter-Rule             4.4.9        |    |     |
           Framed-Protocol             4.4.10.1     | M  |  V  |
           Framed-Routing              4.4.10.2     | M  |  V  |
           Framed-MTU                  4.4.10.3     | M  |  V  |
           Framed-Compression          4.4.10.4     | M  |  V  |
           Framed-IP-Address           4.4.10.5.1   | M  |  V  |
           Framed-IP-Netmask           4.4.10.5.2   | M  |  V  |
           Framed-Route                4.4.10.5.3   | M  |  V  |
           Framed-Pool                 4.4.10.5.4   | M  |  V  |
           Framed-Interface-Id         4.4.10.5.5   | M  |  V  |
           Framed-IPv6-Prefix          4.4.10.5.6   | M  |  V  |
           Framed-IPv6-Route           4.4.10.5.7   | M  |  V  |
           Framed-IPv6-Pool            4.4.10.5.8   | M  |  V  |
           Framed-IPX-Network          4.4.10.6.1   | M  |  V  |
           Framed-Appletalk-Link       4.4.10.7.1   | M  |  V  |
           Framed-Appletalk-Network    4.4.10.7.2   | M  |  V  |
           Framed-Appletalk-Zone       4.4.10.7.3   | M  |  V  |
           ARAP-Features               4.4.10.8.1   | M  |  V  |
           ARAP-Zone-Access            4.4.10.8.2   | M  |  V  |
           Login-IP-Host               4.4.11.1     | M  |  V  |
           Login-IPv6-Host             4.4.11.2     | M  |  V  |
           Login-Service               4.4.11.3     | M  |  V  |
           Login-TCP-Port              4.4.11.4.1   | M  |  V  |
           Login-LAT-Service           4.4.11.5.1   | M  |  V  |
           Login-LAT-Node              4.4.11.5.2   | M  |  V  |
           Login-LAT-Group             4.4.11.5.3   | M  |  V  |
           Login-LAT-Port              4.4.11.5.4   | M  |  V  |
           -----------------------------------------|----+-----|








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4.4.1.  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.  It MUST treat unknown or
   unsupported Service-Types received in a response as a failure and end
   the session with a DIAMETER_INVALID_AVP_VALUE Result-Code.

   When used in a request, the Service-Type AVP SHOULD be considered a
   hint to the server that the NAS believes the user would prefer the
   kind of service indicated.  The server is not required to honor the
   hint.  Furthermore, if the service specified by the server is
   supported, but not compatible with the current mode of access, the
   NAS MUST fail to start the session.  The NAS MUST also generate the
   appropriate error message(s).

   The complete list of defined values that the Service-Type AVP can
   take can be found in [RFC2865] and [RADIUSTypes], but the following
   values require further qualification here:


      Login (1)
         The user should be connected to a host.  The message MAY
         include additional AVPs as defined in Section 4.4.11.4 or
         Section 4.4.11.5.

      Framed (2)
         A Framed Protocol, such as PPP or SLIP, should be started for
         the User.  The message MAY include additional AVPs defined in
         Section 4.4.10, or Section 4.5 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, and then a
         Framed Protocol, such as PPP or SLIP, should be started for the
         User.  The message MAY include additional AVPs defined in
         Section 4.4.10, or Section 4.5 for tunneling services.

4.4.2.  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



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   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 this field's allowed usage range is outside the
   scope of this specification.

4.4.3.  Callback-Id AVP

   The Callback-Id AVP (AVP Code 20) is of type UTF8String and contains
   the name of a place to be called, to be interpreted by the NAS.  This
   AVP MAY be present in an authentication and/or authorization
   response.

   This AVP is not roaming-friendly as it assumes that the Callback-Id
   is configured on the NAS.  Using the Callback-Number AVP
   (Section 4.4.2) is therefore preferable.

4.4.4.  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 allowable to
   the user before termination of the session or before a prompt is
   issued.  The default is none, or system specific.

4.4.5.  Port-Limit AVP

   The Port-Limit AVP (AVP Code 62) is of type Unsigned32 and sets the
   maximum number of ports the NAS provides to the user.  It MAY be used
   in an authentication and/or authorization request as a hint to the
   server that multilink PPP [RFC1990] service is desired, but the
   server is not required to honor the hint in the corresponding
   response.

4.4.6.  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 of these AVPs MAY be present in an authorization
   response.

4.4.7.  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



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   different NASes without regard to filter-list implementation details.
   However, this AVP is not roaming-friendly, as filter naming differs
   from one service provider to another.

   In environments where backward compatibility with RADIUS is not
   required, it is RECOMMENDED that the NAS-Filter-Rule AVP
   (Section 4.4.6) be used instead.

4.4.8.  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 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.

4.4.9.  QoS-Filter-Rule AVP

   The QoS-Filter-Rule AVP (AVP Code 407) is of type QoSFilterRule
   (Section 4.1.1) and provides QoS 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.

   The use of this AVP is NOT RECOMMENDED; the AVPs defined by Korhonen,
   et al. [RFC5777] SHOULD be used instead.

   The following options are defined for the QoSFilterRule filters:

   DSCP <color>  If action is set to tag (Section 4.1.1) this option
         MUST be included in the rule.

         Color values are defined in Nichols, et al. [RFC2474].  Exact
         matching of DSCP values is required (no masks or ranges).

   metering <rate> <color_under> <color_over>  The metering option
         provides Assured Forwarding, as defined in Heinanen, et al.
         [RFC2597]. and MUST be present if the action is set to meter
         (Section 4.1.1) The rate option is the throughput, in bits per
         second, used by the access device to mark packets.  Traffic
         over the rate is marked with the color_over codepoint, and
         traffic under the rate is marked with the color_under
         codepoint.  The color_under and color_over options contain the
         drop preferences and MUST conform to the recommended codepoint
         keywords described in RFC 2597 (e.g., AF13).

         The metering option also supports the strict limit on traffic
         required by Expedited Forwarding, as defined in Davie, et



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         al. [RFC3246].  The color_over option may contain the keyword
         "drop" to prevent forwarding of traffic that exceeds the rate
         parameter.

4.4.10.  Framed Access Authorization AVPs

   This section lists the authorization AVPs necessary to support framed
   access, such as PPP and SLIP.  AVPs defined in this section MAY be
   present in a message if the Service-Type AVP was set to "Framed" or
   "Callback Framed".

4.4.10.1.  Framed-Protocol AVP

   The Framed-Protocol AVP (AVP Code 7) is of type Enumerated and
   contains the framing to be used for framed access.  This AVP MAY be
   present in both requests and responses.  The supported values are
   listed in [RADIUSTypes].

4.4.10.2.  Framed-Routing AVP

   The Framed-Routing AVP (AVP Code 10) is of type Enumerated and
   contains the routing method for the user when the user is a router to
   a network.  This AVP SHOULD only be present in authorization
   responses.  The supported values are listed in [RADIUSTypes].

4.4.10.3.  Framed-MTU AVP

   The Framed-MTU AVP (AVP Code 12) is of type Unsigned32 and contains
   the Maximum Transmission Unit (MTU) to be configured for the user,
   when it is not negotiated by some other means (such as PPP).  This
   AVP SHOULD only be present in authorization responses.  The MTU value
   MUST be in the range from 64 to 65535.

4.4.10.4.  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.  The NAS is
   responsible for applying the proper compression protocol to the
   appropriate link traffic.

   The supported values are listed in [RADIUSTypes].





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4.4.10.5.  IP Access Authorization AVPs

   The AVPs defined in this section are used when the user requests, or
   is being granted, access service to IP.

4.4.10.5.1.  Framed-IP-Address AVP

   The Framed-IP-Address AVP (AVP Code 8) [RFC2865] is of type
   OctetString and contains an IPv4 address of the type specified in the
   attribute value to be configured for the user.  It MAY be used in an
   authorization request as a hint to the server that a specific address
   is desired, but the server is not required to honor the hint in the
   corresponding response.

   Two values have special significance: 0xFFFFFFFF and 0xFFFFFFFE.  The
   value 0xFFFFFFFF indicates that the NAS should allow the user to
   select an address (i.e., 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).

4.4.10.5.2.  Framed-IP-Netmask AVP

   The Framed-IP-Netmask AVP (AVP Code 9) is of type OctetString and
   contains the four octets of the IPv4 netmask to be configured for the
   user when the user is a router to a network.  It MAY be used in an
   authorization request as a hint to the server that a specific netmask
   is desired, but the server is not required to honor the hint in the
   corresponding response.  This AVP MUST be present in a response if
   the request included this AVP with a value of 0xFFFFFFFF.

4.4.10.5.3.  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 of these 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.  This is
   followed by a space, a gateway address in dotted quad form, a space,
   and one or more metrics separated by spaces; for example,

      "192.0.2.0/24 192.0.2.1 1"

   The length specifier may be omitted, in which case it should default
   to 8 bits for class A prefixes, to 16 bits for class B prefixes, and
   to 24 bits for class C prefixes; for example,



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      "192.0.2.0 192.0.2.1 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.

4.4.10.5.4.  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
   [RFC2865], the encoding of the Data field SHOULD also conform to the
   rules for the UTF8String Data Format.

4.4.10.5.5.  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.

4.4.10.5.6.  Framed-IPv6-Prefix AVP

   The Framed-IPv6-Prefix AVP (AVP Code 97) is of type OctetString and
   contains the IPv6 prefix to be configured for the user.  One or more
   AVPs MAY be used in authorization requests as a hint to the server
   that specific IPv6 prefixes are desired, but the server is not
   required to honor the hint in the corresponding response.

4.4.10.5.7.  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 of these 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.  This is followed by a space, a gateway
   address in hexadecimal notation, a space, and one or more metrics
   separated by spaces; for example,





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      "2001:db8::/32 2001:db8:106: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
   in:

      "2001:db8::/32 :: 1"

4.4.10.5.8.  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
   [RFC3162], the encoding of the Data field SHOULD also conform to the
   rules for the UTF8String Data Format.

4.4.10.6.  IPX Access AVPs

   The AVPs defined in this section are used when the user requests, or
   is being granted, access to an IPX network service [IPX].

4.4.10.6.1.  Framed-IPX-Network AVP

   The Framed-IPX-Network AVP (AVP Code 23) is of type Unsigned32 and
   contains the IPX Network number to be configured for the user.  It
   MAY be used in an authorization request as a hint to the server that
   a specific address is desired, but the server is not required to
   honor the hint in the corresponding response.

   Two addresses have special significance: 0xFFFFFFFF and 0xFFFFFFFE.
   The value 0xFFFFFFFF indicates that the NAS should allow the user to
   select an address (i.e., Negotiated).  The value 0xFFFFFFFE indicates
   that the NAS should select an address for the user (e.g., assign it
   from a pool of one or more IPX networks kept by the NAS).

4.4.10.7.  AppleTalk Network Access AVPs

   The AVPs defined in this section are used when the user requests, or
   is being granted, access to an AppleTalk network [AppleTalk].

4.4.10.7.1.  Framed-AppleTalk-Link AVP

   The Framed-AppleTalk-Link AVP (AVP Code 37) is of type Unsigned32 and
   contains the AppleTalk network number that should be used for the
   serial link to the user, which is another AppleTalk router.  This AVP



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   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 0 to 65,535.  The
   special value of 0 indicates an unnumbered serial link.  A value of 1
   to 65,535 means that the serial line between the NAS and the user
   should be assigned that value as an AppleTalk network number.

4.4.10.7.2.  Framed-AppleTalk-Network AVP

   The Framed-AppleTalk-Network AVP (AVP Code 38) is of type Unsigned32
   and contains the AppleTalk Network number that 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 0 to 65,535.  The
   special value 0 indicates that the NAS should assign a network for
   the user, using its default cable range.  A value between 1 and
   65,535 (inclusive) indicates to the AppleTalk Network that the NAS
   should probe to find an address for the user.

4.4.10.7.3.  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 this field's allowed range is outside the scope
   of this specification.

4.4.10.8.  AppleTalk Remote Access AVPs

   The AVPs defined in this section are used when the user requests, or
   is being granted, access to the AppleTalk network via the AppleTalk
   Remote Access Protocol [ARAP].  They are only present if the Framed-
   Protocol AVP (Section 4.4.10.1) is set to ARAP.  Section 2.2 of RFC
   2869 describes the operational use of these attributes.

4.4.10.8.1.  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 RFC 2869 for more information about the
   format of this AVP.




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4.4.10.8.2.  ARAP-Zone-Access AVP

   The ARAP-Zone-Access AVP (AVP Code 72) is of type Enumerated and MAY
   be present in the AA-Accept message if the Framed-Protocol AVP is set
   to the value of ARAP.

   The supported values are listed in [RADIUSTypes] and defined in RFC
   2869.

4.4.11.  Non-Framed Access Authorization AVPs

   This section contains the authorization AVPs that are needed to
   support terminal server functionality.  AVPs defined in this section
   MAY be present in a message if the Service-Type AVP was set to
   "Login" or "Callback Login".

4.4.11.1.  Login-IP-Host AVP

   The Login-IP-Host AVP (AVP Code 14) [RFC2865] is of type OctetString
   and contains the IPv4 address of a host with which to connect the
   user when the Login-Service AVP is included.  It MAY be used in an
   AA-Request command as a hint to the Diameter Server that a specific
   host is desired, but the Diameter Server is not required to honor the
   hint in the AA-Answer.

   Two addresses have special significance: all ones and 0.  The value
   of all ones indicates that the NAS SHOULD allow the user to select an
   address.  The value 0 indicates that the NAS SHOULD select a host to
   connect the user to.

4.4.11.2.  Login-IPv6-Host AVP

   The Login-IPv6-Host AVP (AVP Code 98) [RFC3162] is of type
   OctetString and contains the IPv6 address of a host with which to
   connect the user when the Login-Service AVP is included.  It MAY be
   used in an AA-Request command as a hint to the Diameter Server that a
   specific host is desired, but the Diameter Server is not required to
   honor the hint in the AA-Answer.

   Two addresses have special significance,
   0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF and 0.  The value
   0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF indicates that the NAS SHOULD
   allow the user to select an address.  The value 0 indicates that the
   NAS SHOULD select a host to connect the user to.







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4.4.11.3.  Login-Service AVP

   The Login-Service AVP (AVP Code 15) is of type Enumerated and
   contains the service that 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 RFC 2869.

4.4.11.4.  TCP Services

   The AVP described in the following section MAY be present if the
   Login-Service AVP is set to Telnet, Rlogin, TCP Clear, or TCP Clear
   Quiet.

4.4.11.4.1.  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
   65,535.

4.4.11.5.  LAT Services

   The AVPs described in this section MAY be present if the Login-
   Service AVP is set to LAT [LAT].

4.4.11.5.1.  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 this service attribute when dealing with clustered
   systems.  In these environments, several different time-sharing hosts
   share the same resources (disks, printers, etc.), and administrators
   often configure each host 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.
   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).



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   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 lowercase
   alphabetics, and the ISO Latin-1 character set extension
   [ISO.8859-1.1987].  All LAT string comparisons are case insensitive.

4.4.11.5.2.  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 Login-
   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 lowercase
   alphabetics, and the ISO Latin-1 character set extension
   [ISO.8859-1.1987].  All LAT string comparisons are case insensitive.

4.4.11.5.3.  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 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 Login-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 bitmap.  The administrators assign a
   bitmap of authorized group codes to each user.  LAT gets these from
   the operating system and uses them 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.







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4.4.11.5.4.  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 in a response if the Login-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
   [ISO.8859-1.1987].

   All LAT string comparisons are case insensitive.

4.5.  NAS Tunneling AVPs

   Some NASes support compulsory tunnel services in which the incoming
   connection data is conveyed by an encapsulation method to a gateway
   elsewhere in the network.  This is typically transparent to the
   service user, and the tunnel characteristics may be described by the
   remote AAA server, based on the user's authorization information.
   Several tunnel characteristics may be returned, and the NAS
   implementation may choose one.  See Zorn, et al. [RFC2868] and Zorn,
   Aboba & Mitton [RFC2867] for further information.

   The following table gives the possible flag values for the session
   level AVPs and specifies whether the AVP MAY be encrypted.





















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                                                    +----------+
                                                    | AVP Flag |
                                                    |  rules   |
                                                    |----+-----|
                                                    |MUST| MUST|
           Attribute Name          Section Defined  |    | NOT |
           -----------------------------------------|----+-----|
           Tunneling                   4.5.1        | M  |  V  |
           Tunnel-Type                 4.5.2        | M  |  V  |
           Tunnel-Medium-Type          4.5.3        | M  |  V  |
           Tunnel-Client-Endpoint      4.5.4        | M  |  V  |
           Tunnel-Server-Endpoint      4.5.5        | M  |  V  |
           Tunnel-Password             4.5.6        | M  |  V  |
           Tunnel-Private-Group-Id     4.5.7        | M  |  V  |
           Tunnel-Assignment-Id        4.5.8        | M  |  V  |
           Tunnel-Preference           4.5.9        | M  |  V  |
           Tunnel-Client-Auth-Id       4.5.10       | M  |  V  |
           Tunnel-Server-Auth-Id       4.5.11       | M  |  V  |
           -----------------------------------------|----+-----|

4.5.1.  Tunneling AVP

   The Tunneling AVP (AVP Code 401) is of type Grouped and contains the
   following AVPs, used to describe a compulsory tunnel service
   ([RFC2868], [RFC2867]).  Its data field has the following ABNF
   grammar:

   Tunneling     ::= < AVP Header: 401 >
                     { Tunnel-Type }
                     { Tunnel-Medium-Type }
                     { Tunnel-Client-Endpoint }
                     { Tunnel-Server-Endpoint }
                     [ Tunnel-Preference ]
                     [ Tunnel-Client-Auth-Id ]
                     [ Tunnel-Server-Auth-Id ]
                     [ Tunnel-Assignment-Id ]
                     [ Tunnel-Password ]
                     [ Tunnel-Private-Group-Id ]

4.5.2.  Tunnel-Type AVP

   The Tunnel-Type AVP (AVP Code 64) is of type Enumerated and contains
   the tunneling protocol(s) to be used (in the case of a tunnel
   initiator) or 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.




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   The Tunnel-Type AVP SHOULD also be included in ACR 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 were received with the Result-Code indicating a
   failure.

   The supported values are listed in [RADIUSTypes].

4.5.3.  Tunnel-Medium-Type AVP

   The Tunnel-Medium-Type AVP (AVP Code 65) is of type Enumerated and
   contains the transport medium to use when creating a tunnel for
   protocols (such as L2TP [RFC3931]) that can operate over multiple
   transports.  It MAY be used in an authorization request as a hint to
   the server that a specific medium is desired, but the server is not
   required to honor the hint in the corresponding response.

   The supported values are listed in [RADIUSTypes].

4.5.4.  Tunnel-Client-Endpoint AVP

   The Tunnel-Client-Endpoint AVP (AVP Code 66) is of type UTF8String
   and contains the address of the initiator end of the tunnel.  It MAY
   be used in an authorization request as a hint to the server that a
   specific endpoint is desired, but the server is not required to honor
   the hint in the corresponding response.  This AVP SHOULD be included
   in the corresponding ACR messages, in which case it indicates the
   address from which the tunnel was initiated.  This AVP, along with
   the Tunnel-Server-Endpoint (Section 4.5.5) and Session-Id AVPs
   ([I-D.ietf-dime-rfc3588bis], Section 8.8), can be used to provide a
   globally unique means to identify a tunnel for accounting and
   auditingpurposes.

   If the value of the Tunnel-Medium-Type AVP (Section 4.5.3) is IPv4
   (1), then this string is either the fully qualified domain name
   (FQDN) of the tunnel client machine, or a "dotted-decimal" IP
   address.  Implementations MUST support the dotted-decimal format and
   SHOULD support the FQDN format for IP addresses.

   If Tunnel-Medium-Type is IPv6 (2), then this string is either the
   FQDN of the tunnel client machine, or a text representation of the
   address in either the preferred or alternate form [RFC3516].
   Conforming implementations MUST support the preferred form and SHOULD
   support both the alternate text form and the FQDN format for IPv6
   addresses.




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   If Tunnel-Medium-Type is neither IPv4 nor IPv6, then this string is a
   tag referring to configuration data local to the Diameter client that
   describes the interface or medium-specific client address to use.

4.5.5.  Tunnel-Server-Endpoint AVP

   The Tunnel-Server-Endpoint AVP (AVP Code 67) is of type 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 ACR messages, in
   which case it indicates the address from which the tunnel was
   initiated.  This AVP, along with the Tunnel-Client-Endpoint
   (Section 4.5.4) and Session-Id AVP ([I-D.ietf-dime-rfc3588bis],
   Section 8.8), can 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 server machine, or a
   "dotted-decimal" IP address.  Implementations MUST support the
   dotted-decimal format and SHOULD support the FQDN format for IP
   addresses.

   If Tunnel-Medium-Type is IPv6 (2), then this string is either the
   FQDN of the tunnel server machine, or a text representation of the
   address in either the preferred or alternate form [RFC3516].
   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 or medium-specific server address to use.

4.5.6.  Tunnel-Password AVP

   The Tunnel-Password AVP (AVP Code 69) is of type OctetString and may
   contain a password to be used to authenticate to a remote server.

   The Tunnel-Password AVP SHOULD NOT be used in untrusted proxy
   environments without encrypting it by using end-to-end security
   techniques.

4.5.7.  Tunnel-Private-Group-Id AVP

   The Tunnel-Private-Group-Id AVP (AVP Code 81) is of type OctetString
   and contains the group Id for a particular tunneled session.  The



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   Tunnel-Private-Group-Id AVP MAY be included in an authorization
   request if the tunnel initiator can predetermine the group resulting
   from a particular connection.  It 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 ACR messages that pertain to the tunneled session.

4.5.8.  Tunnel-Assignment-Id AVP

   The Tunnel-Assignment-Id AVP (AVP Code 82) is of type OctetString and
   is used to indicate to the tunnel initiator the particular tunnel to
   which a session is to be assigned.  Some tunneling protocols, such as
   PPTP [RFC2637] and L2TP [RFC3931], allow for sessions between the
   same two tunnel endpoints to be multiplexed over the same tunnel and
   also for a given session to use its own dedicated tunnel.  This
   attribute provides a mechanism for Diameter to inform the tunnel
   initiator (for example, a 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 providing an
   appropriate level of service.  It is expected that any QoS-related
   Diameter tunneling attributes defined in the future accompanying this
   one 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 only intended to be of
   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
   to 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 pertaining to the
   tunneled session.



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   If a tunnel initiator supports the Tunnel-Assignment-Id AVP, then it
   should assign a session to a tunnel in the following manner:

   o  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.

   o  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.

   o  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
      session and for subsequent ones established without the Tunnel-
      Assignment-Id attribute.  A tunnel initiator MUST NOT assign a
      session for which a Tunnel-Assignment-Id AVP was not specified to
      a named tunnel (i.e., one that was initiated by a session
      specifying this AVP).

   Note that the same Id may be used to name different tunnels if these
   tunnels are between different endpoints.

4.5.9.  Tunnel-Preference AVP

   The Tunnel-Preference AVP (AVP Code 83) is of type Unsigned32 and is
   used to identify the relative preference assigned to each tunnel when
   more than one set of tunneling AVPs is returned within separate
   Grouped-AVP AVPs.  It MAY be used in an authorization request as a
   hint to the server that a specific preference is desired, but the
   server is not required to honor the hint in the corresponding
   response.

   For example, suppose that AVPs describing two tunnels are returned by
   the server, one with a Tunnel-Type of PPTP and the other with a
   Tunnel-Type of L2TP.  If the tunnel initiator supports only one of
   the Tunnel-Types returned, it will initiate a tunnel of that type.
   If, however, it supports both tunnel protocols, it SHOULD use the
   value of the Tunnel-Preference AVP to decide which tunnel should be
   started.  The tunnel with the lowest numerical 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.





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4.5.10.  Tunnel-Client-Auth-Id AVP

   The Tunnel-Client-Auth-Id AVP (AVP Code 90) is of type UTF8String and
   specifies the name used by the tunnel initiator during the
   authentication phase of tunnel establishment.  It MAY be used in an
   authorization request as a hint to the server that a specific
   preference is desired, but the server is not required to honor the
   hint in the corresponding response.  This AVP MUST be present in the
   authorization response if an authentication name other than the
   default is desired.  This AVP SHOULD be included in the ACR messages
   pertaining to the tunneled session.

4.5.11.  Tunnel-Server-Auth-Id AVP

   The Tunnel-Server-Auth-Id AVP (AVP Code 91) is of type UTF8String and
   specifies the name used by the tunnel terminator during the
   authentication phase of tunnel establishment.  It MAY be used in an
   authorization request as a hint to the server that a specific
   preference is desired, but the server is not required to honor the
   hint in the corresponding response.  This AVP MUST be present in the
   authorization response if an authentication name other than the
   default is desired.  This AVP SHOULD be included in the ACR messages
   pertaining to the tunneled session.

4.6.  NAS Accounting AVPs

   Applications implementing this specification use Diameter Accounting
   (as defined in [I-D.ietf-dime-rfc3588bis]) and the AVPs in the
   following section.  Service-specific AVP usage is defined in the
   tables in Section 5.

   If accounting is active, Accounting Request (ACR) messages SHOULD be
   sent after the completion of any Authentication or Authorization
   transaction and at the end of a Session.  The value of the
   Accounting-Record-Type AVP [I-D.ietf-dime-rfc3588bis] indicates the
   type of event.  All other AVPs identify the session and provide
   additional information relevant to the event.

   The successful completion of the first Authentication or
   Authorization transaction SHOULD cause a START_RECORD to be sent.  If
   additional Authentications or Authorizations occur in later
   transactions, the first exchange should generate a START_RECORD, and
   the later an INTERIM_RECORD.  For a given session, there MUST only be
   one set of matching START and STOP records, with any number of
   INTERIM_RECORDS in between, or one EVENT_RECORD indicating the reason
   a session wasn't started.

   The following table gives the possible flag values for the session



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   level AVPs and specifies whether the AVP MAY be encrypted.

                                                    +----------+
                                                    | AVP Flag |
                                                    |  rules   |
                                                    |----+-----|
                                            Section |MUST| MUST|
           Attribute Name                   Defined |    |  NOT|
           -----------------------------------------|----+-----|
           Accounting-Input-Octets           4.6.1  | M  |  V  |
           Accounting-Output-Octets          4.6.2  | M  |  V  |
           Accounting-Input-Packets          4.6.3  | M  |  V  |
           Accounting-Output-Packets         4.6.4  | M  |  V  |
           Acct-Session-Time                 4.6.5  | M  |  V  |
           Acct-Authentic                    4.6.6  | M  |  V  |
           Accounting-Auth-Method            4.6.7  | M  |  V  |
           Acct-Delay-Time                   4.6.8  | M  |  V  |
           Acct-Link-Count                   4.6.9  | M  |  V  |
           Acct-Tunnel-Connection            4.6.10 | M  |  V  |
           Acct-Tunnel-Packets-Lost          4.6.11 | M  |  V  |
           -----------------------------------------|----+-----|

4.6.1.  Accounting-Input-Octets AVP

   The Accounting-Input-Octets AVP (AVP Code 363) is of type Unsigned64
   and contains the number of octets received from the user.

   For NAS usage, this AVP indicates how many octets have been received
   from the port in the course of this session.  It can only be present
   in ACR messages with an Accounting-Record-Type
   [I-D.ietf-dime-rfc3588bis] of INTERIM_RECORD or STOP_RECORD.

4.6.2.  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 NAS usage, this AVP indicates how many octets have been sent to
   the port in the course of this session.  It can only be present in
   ACR messages with an Accounting-Record-Type of INTERIM_RECORD or
   STOP_RECORD.

4.6.3.  Accounting-Input-Packets AVP

   The Accounting-Input-Packets (AVP Code 365) is of type Unsigned64 and
   contains the number of packets received from the user.

   For NAS usage, this AVP indicates how many packets have been received



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   from the port over the course of a session being provided to a Framed
   User.  It can only be present in ACR messages with an Accounting-
   Record-Type of INTERIM_RECORD or STOP_RECORD.

4.6.4.  Accounting-Output-Packets AVP

   The Accounting-Output-Packets (AVP Code 366) is of type Unsigned64
   and contains the number of IP packets sent to the user.

   For NAS usage, this AVP indicates how many packets have been sent to
   the port over the course of a session being provided to a Framed
   User.  It can only be present in ACR messages with an Accounting-
   Record-Type of INTERIM_RECORD or STOP_RECORD.

4.6.5.  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.

4.6.6.  Acct-Authentic AVP

   The Acct-Authentic AVP (AVP Code 45) is of type Enumerated and
   specifies how the user was authenticated.  The supported values are
   listed in [RADIUSTypes].

4.6.7.  Accounting-Auth-Method AVP

   The Accounting-Auth-Method AVP (AVP Code 406) is of type Enumerated.
   A NAS MAY include this AVP in an Accounting-Request message to
   indicate the method used to authenticate the user.  (Note that this
   AVP is semantically equivalent, and the supported values are
   identical, to the Microsoft MS-Acct-Auth-Type vendor-specific RADIUS
   attribute [RFC2548]).

4.6.8.  Acct-Delay-Time AVP

   The Acct-Delay-Time AVP (AVP Code 41) is of type Unsigned32 and
   indicates the number of seconds the Diameter client has been trying
   to send the Accounting-Request (ACR).  The accounting server may
   subtract this value from the time when 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



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   was rejected because it could not be delivered.  In these cases, the
   command MAY be buffered and transmitted 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
   re-sent 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.

4.6.9.  Acct-Link-Count AVP

   The Acct-Link-Count AVP (AVP Code 51) is of type Unsigned32 and
   indicates the total number of links that have been active (current or
   closed) in a given multilink session at the time the accounting
   record is generated.  This AVP MAY be included in Accounting-Requests
   for any session that 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
   with Accounting-Record-Type = STOP_RECORD and with the same Acct-
   Multi-Session-Id and unique Session-Ids 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 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

4.6.10.  Acct-Tunnel-Connection AVP

   The Acct-Tunnel-Connection AVP (AVP Code 68) is of type OctetString
   and contains the identifier assigned to the tunnel session.  This
   AVP, along with the Tunnel-Client-Endpoint (Section 4.5.4) and
   Tunnel-Server-Endpoint (Section 4.5.5) AVPs, may be used to provide a



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   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 (Section 4.5.2).  For example, to identify an
   L2TP tunnel connection fully, the L2TP Tunnel Id and Call Id might be
   encoded in this field.  The exact encoding of this field is
   implementation dependent.

4.6.11.  Acct-Tunnel-Packets-Lost AVP

   The Acct-Tunnel-Packets-Lost AVP (AVP Code 86) is of type Unsigned32
   and contains the number of packets lost on a given tunnel.

5.  AVP Occurrence Tables

   The following tables present the AVPs used by NAS applications in NAS
   messages and specify in which Diameter messages they may or may not
   be present.  Messages and AVPs defined in the base Diameter protocol
   [I-D.ietf-dime-rfc3588bis] are not described in this document.  Note
   that AVPs that can only be present within a Grouped AVP are not
   represented in this table.

   The tables use 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    Exactly one instance of the AVP MUST be present in the
           message.

5.1.  AA-Request/Answer AVP Table

   The table in this section is limited to the Command Codes defined in
   this specification.















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                                              +-----------+
                                              |  Command  |
                                              |-----+-----+
                AVP 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 |
                ------------------------------|-----+-----+

































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                                              +-----------+
                                              |  Command  |
                                              |-----+-----+
                Attribute Name                | AAR | AAA |
                ------------------------------|-----+-----+
                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+  | 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 |
                Idle-Timeout                  | 0   | 0-1 |
                Login-IP-Host                 | 0+  | 0+  |
                Login-IPv6-Host               | 0+  | 0+  |
                Login-LAT-Group               | 0-1 | 0-1 |
                Login-LAT-Node                | 0-1 | 0-1 |
                Login-LAT-Port                | 0-1 | 0-1 |
                Login-LAT-Service             | 0-1 | 0-1 |
                Login-Service                 | 0   | 0-1 |
                Login-TCP-Port                | 0   | 0-1 |
                Multi-Round-Time-Out          | 0   | 0-1 |
                ------------------------------|-----+-----+




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                                              +-----------+
                                              |  Command  |
                                              |-----+-----+
                Attribute Name                | AAR | AAA |
                ------------------------------|-----+-----+
                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   |
                Origin-AAA-Protocol           | 0-1 | 0-1 |
                Origin-Host                   | 1   | 1   |
                Origin-Realm                  | 1   | 1   |
                Origin-State-Id               | 0-1 | 0-1 |
                Originating-Line-Info         | 0-1 | 0   |
                Password-Retry                | 0   | 0-1 |
                Port-Limit                    | 0-1 | 0-1 |
                Prompt                        | 0   | 0-1 |
                Proxy-Info                    | 0+  | 0+  |
                QoS-Filter-Rule               | 0   | 0+  |
                Re-Auth-Request-Type          | 0   | 0-1 |
                Redirect-Host                 | 0   | 0+  |
                Redirect-Host-Usage           | 0   | 0-1 |
                Redirect-Max-Cache-Time       | 0   | 0-1 |
                Reply-Message                 | 0   | 0+  |
                Result-Code                   | 0   | 1   |
                Route-Record                  | 0+  | 0   |
                Service-Type                  | 0-1 | 0-1 |
                Session-Id                    | 1   | 1   |
                Session-Timeout               | 0   | 0-1 |
                State                         | 0-1 | 0-1 |
                Tunneling                     | 0+  | 0+  |
                User-Name                     | 0-1 | 0-1 |
                User-Password                 | 0-1 | 0   |
                ------------------------------|-----+-----+

5.2.  Accounting AVP Tables

   The tables in this section are used to show which AVPs defined in
   this document are to be present and used in NAS application
   Accounting messages.  These AVPs are defined in this document, as
   well as in [I-D.ietf-dime-rfc3588bis] and [RFC2866].







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5.2.1.  Framed Access Accounting AVP Table

   The table in this section is used when the Service-Type AVP
   (Section 4.4.1) specifies Framed Access.

                                                    +-----------+
                                                    |  Command  |
                                                    |-----+-----+
             Attribute Name                         | ACR | ACA |
             ---------------------------------------|-----+-----+
             Accounting-Auth-Method                 | 0-1 | 0   |
             Accounting-Input-Octets                | 1   | 0   |
             Accounting-Input-Packets               | 1   | 0   |
             Accounting-Output-Octets               | 1   | 0   |
             Accounting-Output-Packets              | 1   | 0   |
             Accounting-Record-Number               | 0-1 | 0-1 |
             Accounting-Record-Type                 | 1   | 1   |
             Accounting-Realtime-Required           | 0-1 | 0-1 |
             Accounting-Sub-Session-Id              | 0-1 | 0-1 |
             Acct-Application-Id                    | 0-1 | 0-1 |
             Acct-Session-Id                        | 1   | 0-1 |
             Acct-Multi-Session-Id                  | 0-1 | 0-1 |
             Acct-Authentic                         | 1   | 0   |
             Acct-Delay-Time                        | 0-1 | 0   |
             Acct-Interim-Interval                  | 0-1 | 0-1 |
             Acct-Link-Count                        | 0-1 | 0   |
             Acct-Session-Time                      | 1   | 0   |
             Acct-Tunnel-Connection                 | 0-1 | 0   |
             Acct-Tunnel-Packets-Lost               | 0-1 | 0   |
             Authorization-Lifetime                 | 0-1 | 0   |
             Callback-Id                            | 0-1 | 0   |
             Callback-Number                        | 0-1 | 0   |
             Called-Station-Id                      | 0-1 | 0   |
             Calling-Station-Id                     | 0-1 | 0   |
             Class                                  | 0+  | 0+  |
             Connection-Info                        | 0+  | 0   |
             Destination-Host                       | 0-1 | 0   |
             Destination-Realm                      | 1   | 0   |
             Event-Timestamp                        | 0-1 | 0-1 |
             Error-Message                          | 0   | 0-1 |
             Error-Reporting-Host                   | 0   | 0-1 |
             Failed-AVP                             | 0   | 0+  |
             ---------------------------------------|-----+-----+








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                                                   +-----------+
                                                   |  Command  |
                                                   |-----+-----+
            Attribute Name                         | ACR | ACA |
            ---------------------------------------|-----+-----+
            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-Prefix                     | 0+  | 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+  | 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-AAA-Protocol                    | 0-1 | 0-1 |
            Origin-Host                            | 1   | 1   |
            Origin-Realm                           | 1   | 1   |
            Origin-State-Id                        | 0-1 | 0-1 |
            Originating-Line-Info                  | 0-1 | 0   |
            Proxy-Info                             | 0+  | 0+  |
            QoS-Filter-Rule                        | 0+  | 0   |
            Route-Record                           | 0+  | 0   |
            Result-Code                            | 0   | 1   |
            Service-Type                           | 0-1 | 0-1 |
            Session-Id                             | 1   | 1   |
            Termination-Cause                      | 0-1 | 0-1 |
            Tunnel-Assignment-Id                   | 0-1 | 0   |
            Tunnel-Client-Endpoint                 | 0-1 | 0   |
            Tunnel-Medium-Type                     | 0-1 | 0   |
            Tunnel-Private-Group-Id                | 0-1 | 0   |
            Tunnel-Server-Endpoint                 | 0-1 | 0   |
            Tunnel-Type                            | 0-1 | 0   |
            User-Name                              | 0-1 | 0-1 |
            ---------------------------------------|-----+-----+





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5.2.2.  Non-Framed Access Accounting AVP Table

   The table in this section is used when the Service-Type AVP
   (Section 4.4.1) specifies Non-Framed Access.

                                                   +-----------+
                                                   |  Command  |
                                                   |-----+-----+
            Attribute Name                         | ACR | ACA |
            ---------------------------------------|-----+-----+
            Accounting-Auth-Method                 | 0-1 | 0   |
            Accounting-Input-Octets                | 1   | 0   |
            Accounting-Output-Octets               | 1   | 0   |
            Accounting-Record-Type                 | 1   | 1   |
            Accounting-Record-Number               | 0-1 | 0-1 |
            Accounting-Realtime-Required           | 0-1 | 0-1 |
            Accounting-Sub-Session-Id              | 0-1 | 0-1 |
            Acct-Application-Id                    | 0-1 | 0-1 |
            Acct-Session-Id                        | 1   | 0-1 |
            Acct-Multi-Session-Id                  | 0-1 | 0-1 |
            Acct-Authentic                         | 1   | 0   |
            Acct-Delay-Time                        | 0-1 | 0   |
            Acct-Interim-Interval                  | 0-1 | 0-1 |
            Acct-Link-Count                        | 0-1 | 0   |
            Acct-Session-Time                      | 1   | 0   |
            Authorization-Lifetime                 | 0-1 | 0   |
            Callback-Id                            | 0-1 | 0   |
            Callback-Number                        | 0-1 | 0   |
            Called-Station-Id                      | 0-1 | 0   |
            Calling-Station-Id                     | 0-1 | 0   |
            Class                                  | 0+  | 0+  |
            Connection-Info                        | 0+  | 0   |
            Destination-Host                       | 0-1 | 0   |
            Destination-Realm                      | 1   | 0   |
            Event-Timestamp                        | 0-1 | 0-1 |
            Error-Message                          | 0   | 0-1 |
            Error-Reporting-Host                   | 0   | 0-1 |
            Failed-AVP                             | 0   | 0+  |
            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   |
            ---------------------------------------|-----+-----+




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                                                   +-----------+
                                                   |  Command  |
                                                   |-----+-----+
            Attribute Name                         | ACR | ACA |
            ---------------------------------------|-----+-----+
            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-AAA-Protocol                    | 0-1 | 0-1 |
            Origin-Host                            | 1   | 1   |
            Origin-Realm                           | 1   | 1   |
            Origin-State-Id                        | 0-1 | 0-1 |
            Originating-Line-Info                  | 0-1 | 0   |
            Proxy-Info                             | 0+  | 0+  |
            QoS-Filter-Rule                        | 0+  | 0   |
            Route-Record                           | 0+  | 0   |
            Result-Code                            | 0   | 1   |
            Session-Id                             | 1   | 1   |
            Service-Type                           | 0-1 | 0-1 |
            Termination-Cause                      | 0-1 | 0-1 |
            User-Name                              | 0-1 | 0-1 |
            ---------------------------------------|-----+-----+

6.  IANA Considerations

   Several of the namespaces used in this document are managed by the
   Internet Assigned Numbers Authority [IANA], including the AVP Codes
   [AVP-Codes], AVP Specific Values [AVP-Vals], Application IDs
   [App-Ids], Command Codes [Command-Codes] and RADIUS Attribute Values
   [RADIUSTypes].

   For the current values allocated, and the policies governing
   allocation in those namespaces, please see the above-referenced
   registries.

7.  Security Considerations

   This document describes the extension of Diameter for the NAS
   application.  The security considerations of the Diameter protocol
   itself are discussed in [I-D.ietf-dime-rfc3588bis].  Use of this
   application of Diameter MUST take into consideration the security
   issues and requirements of the Base protocol.

   The use of the User-Password (Section 4.3.1) and Tunnel-Password
   (Section 4.5.6) AVPs is not safe in the absence of end-to-end



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   security; however, end-to-end security for the Diameter protocol is
   outside the scope of this document.

   This document does not contain a security protocol but does discuss
   how PPP authentication protocols can be carried within the Diameter
   protocol.  The PPP authentication protocols described are PAP and
   CHAP.

   The use of PAP SHOULD be discouraged, as it exposes users' passwords
   to possibly non-trusted entities.  However, PAP is also frequently
   used for use with One-Time Passwords, which do not expose a security
   risk.

   This document also describes how CHAP can be carried within the
   Diameter protocol, which is required for RADIUS backward
   compatibility.  The CHAP protocol, as used in a RADIUS environment,
   facilitates authentication replay attacks.

   The use of the EAP authentication protocols [RFC4072] can offer
   better security, given a method suitable for the circumstances.

8.  References

8.1.  Normative References

   [ANITypes]                  NANPA Number Resource Info, "ANI
                               Assignments", <http://www.nanpa.com/
                               number_resource_info/
                               ani_ii_assignments.html>.

   [I-D.ietf-dime-rfc3588bis]  Fajardo, V., Arkko, J., Loughney, J., and
                               G. Zorn, "Diameter Base Protocol",
                               draft-ietf-dime-rfc3588bis-33 (work in
                               progress), May 2012.

   [RFC1994]                   Simpson, W., "PPP Challenge Handshake
                               Authentication Protocol (CHAP)",
                               RFC 1994, August 1996.

   [RFC2119]                   Bradner, S., "Key words for use in RFCs
                               to Indicate Requirement Levels", BCP 14,
                               RFC 2119, March 1997.

   [RFC2865]                   Rigney, C., Willens, S., Rubens, A., and
                               W. Simpson, "Remote Authentication Dial
                               In User Service (RADIUS)", RFC 2865,
                               June 2000.




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   [RFC3162]                   Aboba, B., Zorn, G., and D. Mitton,
                               "RADIUS and IPv6", RFC 3162, August 2001.

   [RFC3516]                   Nerenberg, L., "IMAP4 Binary Content
                               Extension", RFC 3516, April 2003.

   [RFC3539]                   Aboba, B. and J. Wood, "Authentication,
                               Authorization and Accounting (AAA)
                               Transport Profile", RFC 3539, June 2003.

8.2.  Informative References

   [ARAP]                      Apple Computer, "Apple Remote Access
                               Protocol (ARAP) Version 2.0 External
                               Reference Specification", R0612LL/B ,
                               September 1994.

   [AVP-Codes]                 "IANA AAA AVP Codes Registry", <http://
                               www.iana.org/assignments/aaa-parameters/
                               aaa-parameters.xml#aaa-parameters-1>.

   [AVP-Vals]                  "IANA AAA AVP Specific Values", <http://
                               www.iana.org/assignments/aaa-parameters/
                               aaa-parameters.xml#aaa-parameters-2>.

   [App-Ids]                   "IANA AAA Application IDs Registry", <htt
                               p://www.iana.org/assignments/
                               aaa-parameters/
                               aaa-parameters.xml#aaa-parameters-1>.

   [AppleTalk]                 Sidhu, G., Andrews, R., and A.
                               Oppenheimer, "Inside AppleTalk", Second
                               Edition Apple Computer, 1990.

   [Command-Codes]             "IANA AAA Command Codes Registry", <http:
                               //www.iana.org/assignments/
                               aaa-parameters/
                               aaa-parameters.xml#command-code-rules>.

   [IANA]                      "Internet Assigned Numbers Authority",
                               <http://www.iana.org/>.

   [IPX]                       Novell, Inc., "NetWare System Technical
                               Interface Overview",  #883-000780-001,
                               June 1989.

   [ISO.8859-1.1987]           International Organization for
                               Standardization, "Information technology



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                               - 8-bit single byte coded graphic -
                               character sets - Part 1: Latin alphabet
                               No. 1, JTC1/SC2", ISO Standard 8859-1,
                               1987.

   [LAT]                       Digital Equipment Corp., "Local Area
                               Transport (LAT) Specification V5.0",  AA-
                               NL26A-TE, June 1989.

   [RADIUSTypes]               IANA, "IANA Radius Attribute Values
                               Registry", <http://www.iana.org/
                               assignments/radius-types-3>.

   [RFC1334]                   Lloyd, B. and W. Simpson, "PPP
                               Authentication Protocols", RFC 1334,
                               October 1992.

   [RFC1661]                   Simpson, W., "The Point-to-Point Protocol
                               (PPP)", STD 51, RFC 1661, July 1994.

   [RFC1990]                   Sklower, K., Lloyd, B., McGregor, G.,
                               Carr, D., and T. Coradetti, "The PPP
                               Multilink Protocol (MP)", RFC 1990,
                               August 1996.

   [RFC2474]                   Nichols, K., Blake, S., Baker, F., and D.
                               Black, "Definition of the Differentiated
                               Services Field (DS Field) in the IPv4 and
                               IPv6 Headers", RFC 2474, December 1998.

   [RFC2548]                   Zorn, G., "Microsoft Vendor-specific
                               RADIUS Attributes", RFC 2548, March 1999.

   [RFC2597]                   Heinanen, J., Baker, F., Weiss, W., and
                               J. Wroclawski, "Assured Forwarding PHB
                               Group", RFC 2597, June 1999.

   [RFC2637]                   Hamzeh, K., Pall, G., Verthein, W.,
                               Taarud, J., Little, W., and G. Zorn,
                               "Point-to-Point Tunneling Protocol",
                               RFC 2637, July 1999.

   [RFC2866]                   Rigney, C., "RADIUS Accounting",
                               RFC 2866, June 2000.

   [RFC2867]                   Zorn, G., Aboba, B., and D. Mitton,
                               "RADIUS Accounting Modifications for
                               Tunnel Protocol Support", RFC 2867,



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                               June 2000.

   [RFC2868]                   Zorn, G., Leifer, D., Rubens, A.,
                               Shriver, J., Holdrege, M., and I. Goyret,
                               "RADIUS Attributes for Tunnel Protocol
                               Support", RFC 2868, June 2000.

   [RFC2869]                   Rigney, C., Willats, W., and P. Calhoun,
                               "RADIUS Extensions", RFC 2869, June 2000.

   [RFC2881]                   Mitton, D. and M. Beadles, "Network
                               Access Server Requirements Next
                               Generation (NASREQNG) NAS Model",
                               RFC 2881, July 2000.

   [RFC2989]                   Aboba, B., Calhoun, P., Glass, S.,
                               Hiller, T., McCann, P., Shiino, H.,
                               Walsh, P., Zorn, G., Dommety, G.,
                               Perkins, C., Patil, B., Mitton, D.,
                               Manning, S., Beadles, M., Chen, X.,
                               Sivalingham, S., Hameed, A., Munson, M.,
                               Jacobs, S., Lim, B., Hirschman, B., Hsu,
                               R., Koo, H., Lipford, M., Campbell, E.,
                               Xu, Y., Baba, S., and E. Jaques,
                               "Criteria for Evaluating AAA Protocols
                               for Network Access", RFC 2989,
                               November 2000.

   [RFC3169]                   Beadles, M. and D. Mitton, "Criteria for
                               Evaluating Network Access Server
                               Protocols", RFC 3169, September 2001.

   [RFC3246]                   Davie, B., Charny, A., Bennet, J.,
                               Benson, K., Le Boudec, J., Courtney, W.,
                               Davari, S., Firoiu, V., and D. Stiliadis,
                               "An Expedited Forwarding PHB (Per-Hop
                               Behavior)", RFC 3246, March 2002.

   [RFC3580]                   Congdon, P., Aboba, B., Smith, A., Zorn,
                               G., and J. Roese, "IEEE 802.1X Remote
                               Authentication Dial In User Service
                               (RADIUS) Usage Guidelines", RFC 3580,
                               September 2003.

   [RFC3931]                   Lau, J., Townsley, M., and I. Goyret,
                               "Layer Two Tunneling Protocol - Version 3
                               (L2TPv3)", RFC 3931, March 2005.




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   [RFC4072]                   Eronen, P., Hiller, T., and G. Zorn,
                               "Diameter Extensible Authentication
                               Protocol (EAP) Application", RFC 4072,
                               August 2005.

   [RFC4301]                   Kent, S. and K. Seo, "Security
                               Architecture for the Internet Protocol",
                               RFC 4301, December 2005.

   [RFC5246]                   Dierks, T. and E. Rescorla, "The
                               Transport Layer Security (TLS) Protocol
                               Version 1.2", RFC 5246, August 2008.

   [RFC5777]                   Korhonen, J., Tschofenig, H.,
                               Arumaithurai, M., Jones, M., and A. Lior,
                               "Traffic Classification and Quality of
                               Service (QoS) Attributes for Diameter",
                               RFC 5777, February 2010.

Appendix A.  Acknowledgements

A.1.  RFC 4005

   The authors would like to thank Carl Rigney, Allan C. Rubens, William
   Allen Simpson, and Steve Willens for their work on the original
   RADIUS protocol, from which many of the concepts in this
   specification were derived.  Thanks, also, to Carl Rigney for
   [RFC2866] and [RFC2869]; Ward Willats for [RFC2869]; Glen Zorn,
   Bernard Aboba, and Dave Mitton for [RFC2867] and [RFC3162]; and Dory
   Leifer, John Shriver, Matt Holdrege, Allan Rubens, Glen Zorn and
   Ignacio Goyret for their work on [RFC2868].  This document stole text
   and concepts from both [RFC2868] and [RFC2869].  Thanks go to Carl
   Williams for providing IPv6-specific text.

   The authors would also like to acknowledge the following people for
   their contributions in the development of the Diameter protocol:
   Bernard Aboba, Jari Arkko, William Bulley, Kuntal Chowdhury, Daniel
   C. Fox, Lol Grant, Nancy Greene, Jeff Hagg, Peter Heitman, Paul
   Krumviede, Fergal Ladley, Ryan Moats, Victor Muslin, Kenneth Peirce,
   Sumit Vakil, John R. Vollbrecht, and Jeff Weisberg.

   Finally, Pat Calhoun would like to thank Sun Microsystems, as most of
   the effort put into this document was done while he was in their
   employ.







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A.2.  RFC 4005bis

   The vast majority of the text in this document was taken directly
   from RFC 4005; the editor owes a debt of gratitude to the authors
   thereof (especially Dave Mitton, who somehow managed to make nroff
   paginate the AVP Occurance Tables correctly!).

   Thanks (in no particular order) to Jai-Jin Lim, Liu Hans, Sebastien
   Decugis, Jouni Korhonen, Mark Jones, Hannes Tschofenig and Stefan
   Winter for their useful reviews and helpful comments.

Author's Address

   Glen Zorn (editor)
   Network Zen
   227/358 Thanon Sanphawut
   Bang Na, Bangkok  10260
   Thailand

   Phone: +66 (0) 87-040-4617
   EMail: glenzorn@gmail.com






























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