Network Working Group P. Calhoun
Request for Comments: 3588 Airespace, Inc.
Category: Standards Track J. Loughney
Nokia
E. Guttman
Sun Microsystems, Inc.
G. Zorn
Cisco Systems, Inc.
J. Arkko
Ericsson
September 2003
Diameter Base Protocol
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
The Diameter base protocol is intended to provide an Authentication,
Authorization and Accounting (AAA) framework for applications such as
network access or IP mobility. Diameter is also intended to work in
both local Authentication, Authorization & Accounting and roaming
situations. This document specifies the message format, transport,
error reporting, accounting and security services to be used by all
Diameter applications. The Diameter base application needs to be
supported by all Diameter implementations.
Conventions Used In This Document
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 BCP 14, RFC 2119
[KEYWORD].
Calhoun, et al. Standards Track [Page 1]
RFC 3588 Diameter Based Protocol September 2003
Table of Contents
1. Introduction................................................. 6
1.1. Diameter Protocol..................................... 9
1.1.1. Description of the Document Set.............. 10
1.2. Approach to Extensibility............................. 11
1.2.1. Defining New AVP Values...................... 11
1.2.2. Creating New AVPs............................ 11
1.2.3. Creating New Authentication Applications..... 11
1.2.4. Creating New Accounting Applications......... 12
1.2.5. Application Authentication Procedures........ 14
1.3. Terminology........................................... 14
2. Protocol Overview............................................ 18
2.1. Transport............................................. 20
2.1.1. SCTP Guidelines.............................. 21
2.2. Securing Diameter Messages............................ 21
2.3. Diameter Application Compliance....................... 21
2.4. Application Identifiers............................... 22
2.5. Connections vs. Sessions.............................. 22
2.6. Peer Table............................................ 23
2.7. Realm-Based Routing Table............................. 24
2.8. Role of Diameter Agents............................... 25
2.8.1. Relay Agents................................. 26
2.8.2. Proxy Agents................................. 27
2.8.3. Redirect Agents.............................. 28
2.8.4. Translation Agents........................... 29
2.9. End-to-End Security Framework......................... 30
2.10. Diameter Path Authorization........................... 30
3. Diameter Header.............................................. 32
3.1. Command Codes......................................... 35
3.2. Command Code ABNF specification....................... 36
3.3. Diameter Command Naming Conventions................... 38
4. Diameter AVPs................................................ 38
4.1. AVP Header............................................ 39
4.1.1. Optional Header Elements..................... 41
4.2. Basic AVP Data Formats................................ 41
4.3. Derived AVP Data Formats.............................. 42
4.4. Grouped AVP Values.................................... 49
4.4.1. Example AVP with a Grouped Data Type......... 50
4.5. Diameter Base Protocol AVPs........................... 53
5. Diameter Peers............................................... 56
5.1. Peer Connections...................................... 56
5.2. Diameter Peer Discovery............................... 56
5.3. Capabilities Exchange................................. 59
5.3.1. Capabilities-Exchange-Request................ 60
5.3.2. Capabilities-Exchange-Answer................. 60
5.3.3. Vendor-Id AVP................................ 61
5.3.4. Firmware-Revision AVP........................ 61
Calhoun, et al. Standards Track [Page 2]
RFC 3588 Diameter Based Protocol September 2003
5.3.5. Host-IP-Address AVP.......................... 62
5.3.6. Supported-Vendor-Id AVP...................... 62
5.3.7. Product-Name AVP............................. 62
5.4. Disconnecting Peer Connections........................ 62
5.4.1. Disconnect-Peer-Request...................... 63
5.4.2. Disconnect-Peer-Answer....................... 63
5.4.3. Disconnect-Cause AVP......................... 63
5.5. Transport Failure Detection........................... 64
5.5.1. Device-Watchdog-Request...................... 64
5.5.2. Device-Watchdog-Answer....................... 64
5.5.3. Transport Failure Algorithm.................. 65
5.5.4. Failover and Failback Procedures............. 65
5.6. Peer State Machine.................................... 66
5.6.1. Incoming connections......................... 68
5.6.2. Events....................................... 69
5.6.3. Actions...................................... 70
5.6.4. The Election Process......................... 71
6. Diameter Message Processing.................................. 71
6.1. Diameter Request Routing Overview..................... 71
6.1.1. Originating a Request........................ 73
6.1.2. Sending a Request............................ 73
6.1.3. Receiving Requests........................... 73
6.1.4. Processing Local Requests.................... 73
6.1.5. Request Forwarding........................... 74
6.1.6. Request Routing.............................. 74
6.1.7. Redirecting Requests......................... 74
6.1.8. Relaying and Proxying Requests............... 75
6.2. Diameter Answer Processing.........................
