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