| 1. Introduction |
| 1.1. Scope |
| 1.2. Terminology |
| 1.3. IUA Overview |
| 1.3.1. Example: SG to MGC |
| 1.3.2. Support for the Management of SCTP Associations between the SG |
| 1.3.3. ASP Fail-over Model and Terminology |
| 1.3.4. Client/Server Model |
| 1.4. Services Provided by the IUA Layer |
| 1.4.1. Support for Transport of Q.921/Q.931 Boundary Primitives |
| 1.4.2. Support for Communication between Layer Management Modules on SG |
| 1.4.3. Support for Management of Active Associations between SG and MGC |
| 1.5. Functions Implemented by the IUA Layer |
| 1.5.1. Mapping |
| 1.5.2. Status of ASPs |
| 1.5.3. SCTP Stream Management |
| 1.5.4. Seamless Network Management Interworking |
| 1.5.5. Congestion Management |
| 1.6. Definition of IUA Boundaries |
| 1.6.1. Definition of IUA/Q.921 Boundary |
| 1.6.2. Definition of IUA/Q.931 Boundary |
| 1.6.3. Definition of SCTP/IUA Boundary |
| 1.6.4. Definition of IUA/Layer-Management Boundary |
| 2. Conventions |
| 3. Protocol Elements |
| 3.1. Common Message Header |
| 3.1.1. Version |
| 3.1.2. Message Classes and Types |
| 3.1.3. Reserved |
| 3.1.4. Message Length |
| 3.1.5. Variable-Length Parameter Format |
| 3.2. IUA Message Header |
| 3.3. IUA Messages |
| 3.3.1. Q.921/Q.931 Boundary Primitives Transport (QPTM) Messages |
| 3.3.1.1. Establish Messages (Request, Confirm, Indication) |
| 3.3.1.2. Release Messages (Request, Indication, Confirmation) |
| 3.3.1.3. Data Messages (Request, Indication) |
| 3.3.1.4. Unit Data Messages (Request, Indication) |
| 3.3.2. Application Server Process Maintenance (ASPM) Messages |
| 3.3.2.1. ASP Up (ASPUP) |
| 3.3.2.2. ASP Up Ack |
| 3.3.2.3. ASP Down (ASPDN) |
| 3.3.2.4. ASP Down Ack |
| 3.3.2.5. ASP Active (ASPAC) |
| 3.3.2.6. ASP Active Ack |
| 3.3.2.7. ASP Inactive (ASPIA) |
| 3.3.2.8. ASP Inactive Ack |
| 3.3.2.9. Heartbeat (BEAT) |
| 3.3.2.10. Heartbeat Ack (BEAT-Ack) |
| 3.3.3. Layer Management (MGMT) Messages |
| 3.3.3.1. Error (ERR) |
| 3.3.3.2. Notify (NTFY) |
| 3.3.3.3. TEI Status Messages (Request, Confirm, and Indication) |
| 3.3.3.4. TEI Query Message (Request) |
| 4. Procedures |
| 4.1. Procedures to Support Service in Section 1.4.1 |
| 4.1.1. Q.921 or Q.931 Primitives Procedures |
| 4.1.2. QPTM Message Procedures |
| 4.2. Procedures to Support Service in Section 1.4.2 |
| 4.2.1. Layer Management Primitives Procedures |
| 4.2.2. Receipt of IUA Peer Management Messages |
| 4.3. Procedures to Support Service in Section 1.4.3 |
| 4.3.1. AS and ASP State Maintenance |
| 4.3.1.1. ASP States |
| 4.3.1.2. AS States |
| 4.3.2. ASPM Procedures for Primitives |
| 4.3.3. ASPM Procedures for Peer-to-Peer Messages |
| 4.3.3.1. ASP Up Procedures |
| 4.3.3.2. ASP Down Procedures |
| 4.3.3.3. IUA Version Control |
| 4.3.3.4. ASP Active Procedures |
| 4.3.3.5. ASP Inactive Procedures |
| 4.3.3.6. Notify Procedures |
| 4.3.3.7. Heartbeat |
| 5. Examples |
| 5.1. Establishment of Association and Traffic between SGs and ASPs |
| 5.1.1. Single ASP in an Application Server (1+0 sparing) |
| 5.1.2. Two ASPs in Application Server (1+1 sparing) |
| 5.1.3. Two ASPs in an Application Server (1+1 sparing, load-sharing |
| 5.1.4. Three ASPs in an Application Server (n+k sparing, load-sharing |
| 5.1.5. Interface Identifier Configuration Mismatch Example |
| 5.2. ASP Traffic Fail-over Examples |
| 5.2.1. (1+1 Sparing, withdrawal of ASP, Backup Over-ride) |
| 5.2.2. (1+1 Sparing, Backup Over-ride) |
| 5.2.3. (n+k Sparing, Load-sharing case, withdrawal of ASP) |
| 5.3. Q.921/Q.931 Primitives Backhaul Examples |
| 5.4. Layer Management Communication Examples |
| 6. Security |
| 7. IANA Considerations |
| 7.1. SCTP Payload Protocol Identifier |
| 7.2. IUA Protocol Extensions |
| 7.2.1. IETF-Defined Message Classes |
| 7.2.2. IETF-Defined Message Types |
| 7.2.3. IETF-Defined TLV Parameter Extension |
| 8. Timer Values |
| 9. Acknowledgements |
| 10. References |
| 10.1. Normative References |
| 10.2. Informative References |
| 11. Change Log |
| 12. Appendix A |
| 13. Authors' Addresses |
| 14. Full Copyright Statement |
| 15. Intellectual Property |
| 16. Acknowledgement |
