| Network Working Group | G. Zorn |
| Internet-Draft | Network Zen |
| Updates: 4005 (if approved) | L.M. Morand |
| Intended status: Standards Track | Orange Labs |
| Expires: February 24, 2012 | T.H. Hiller |
| Lucent Technologies | |
| August 23, 2011 |
The RADIUS-Diameter Gateway (RADIA) Application
draft-zorn-dime-radia-gate-04.txt
This document describes the Diameter RADIUS-Diameter Gateway (RADIA) Application, which is designed to facillitate the interoperability of Authentication, Authorization and Accounting (AAA) systems based upon RADIUS and Diameter.
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 February 24, 2012.
Copyright (c) 2011 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 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English.
The Diameter Network Access Server (NASREQ) Application [RFC4005] specifies methods to deal with various interactions between the RADIUS [RFC2865] and Diameter [RFC3588] protocols. In particular, the translation of RADIUS messages and attributes to and from Diameter commands and Attribute-Value Pairs (AVPs) is described at some length. However, there is a fundamental and insurmountable problem with attempting to translate Diameter protocol elements into RADIUS protocol elements: a single Diameter AVP may be much larger than an entire RADIUS message. Various workarounds have been proposed to ameliorate this proble, including limiting the size of Diameter elements that might require translation into RADIUS and returning an error upon receipt of an untranslatable AVP. The former approach uneccessarily limits the utility of, for example, the NASREQ application in pure Diameter deployments while the latter can result in the denial of service to otherwise legitimate users.
This document describes a simple method to solve the problems of interaction between RADIUS and Diameter by taking advantage of the fact thata RADIUS message can fit into a single Diameter AVP.
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].
The following sections define the syntax, semantics and usage of the RADIA application.
Servers and proxies supporting the RADIUS-Diameter Gateway application MUST advertise support by including the value <AID> in the Auth-Application-Id of the Capabilities-Exchange-Request (CER), Accounting-Request (ACR), Accounting-Answer (ACA), RADIA-Request (RDR), and RADIA-Answer (RDA) messages.
Session usage in the RADIA application is identical to that in NASREQ.
The RADIA application defines two new commands: Gateway-Request (RDR) and Gateway-Answer (RDA). The following sections describe these commands.
<RDR> ::= < Diameter Header: CC1, REQ, PXY >
{ Origin-Host }
{ Origin-Realm }
{ Destination-Realm }
{ Auth-Application-Id }
{ Radius-Message}
[ Destination-Host ]
* [ Proxy-Info ]
* [ Route-Record ]
* [ AVP ]
The peer sends the RADIA-Request (RDR) command, indicated by the Command-Code field set to <CC1> and the Command Flags' 'R' bit set, in order to transmit a RADIUS message (encapsulated in the Radius-Message AVP [RadMsg]) toward its final destination. The Radius-Message AVP will generally encapsulate a RADIUS request message (e.g., Access-Request).
Message format:
<RDA> ::= < Diameter Header: CC2, REQ, PXY >
{ Origin-Host }
{ Origin-Realm }
{ Destination-Realm }
{ Auth-Application-Id }
{ Radius-Message}
[ Destination-Host ]
* [ Proxy-Info ]
* [ Route-Record ]
* [ AVP ]
The peer sends the RADIA-Answer (RDA) command, indicated by the Command-Code field set to <CC2> and the Command Flags' 'R' bit set, in order to transmit a RADIUS message (encapsulated in the Radius-Message AVP [RadMsg]) toward its final destination. The Radius-Message AVP will generally encapsulate a RADIUS reply message (e.g., Access-Accept).
Message format:
This section describes the single AVP specific to the RADIUS-Diameter Gateway application.
The Radius-Message AVP (AVP code <AVP>) is of type OctetString. The 'M' bit MUST be set and the 'V' bit MUST NOT be set. The AVP contains a complete RADIUS message.
The protocol defined in this specification has no effect upon the security of either Diameter or RADIUS.
Upon publication of this memo as an RFC, IANA is requested to assign values as described in the following sections.
An application identifier for Diameter RADIUS-Diameter Gateway (<AID>, Section 3) must be assigned according to the policy specified in Section 11.3 of RFC 3588.
Command codes must be assigned for the RADIA-Request (RDR) (<CC1>, Section 3.3.1) and RADIA-Answer (RDA) (<CC2>, Section 3.3.2) commands according to the policy specified in RFC 3588, Section 11.2.1.
A code must be assigned for the following AVP using the policy specified in RFC 3588, Section 11.1.1: Radius-Message (<AVP>, Section 3.4.1).
| [RFC4005] | Calhoun, P., Zorn, G., Spence, D. and D. Mitton, "Diameter Network Access Server Application", RFC 4005, August 2005. |
| [RFC2865] | Rigney, C., Willens, S., Rubens, A. and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000. |
| [RFC3588] | Calhoun, P., Loughney, J., Guttman, E., Zorn, G. and J. Arkko, "Diameter Base Protocol", RFC 3588, September 2003. |
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. |