14. IANA Considerations
This chapter describes SCTP protocol registration requirements in IANA (Internet Assigned Numbers Authority) registries.
14.1. SCTP Chunk Type Registration
IANA maintains the SCTP Chunk Type registry.
14.1.1. Chunk Type Value Ranges
Chunk Type Field: 8-bit value (0-255)
Allocation Policy:
- 0-63: Defined chunk types (defined by this RFC)
- 64-126: Reserved for IETF Review
- 127: Reserved for IETF-defined extensions
- 128-190: Reserved for IETF Review
- 191: Reserved for IETF-defined extensions
- 192-255: Experimental and private use
14.1.2. Defined Chunk Types
Chunk types defined by this RFC:
| Type | Name | Reference |
|---|---|---|
| 0 | DATA | 3.3.1 |
| 1 | INIT | 3.3.2 |
| 2 | INIT ACK | 3.3.3 |
| 3 | SACK | 3.3.4 |
| 4 | HEARTBEAT | 3.3.5 |
| 5 | HEARTBEAT ACK | 3.3.6 |
| 6 | ABORT | 3.3.7 |
| 7 | SHUTDOWN | 3.3.8 |
| 8 | SHUTDOWN ACK | 3.3.9 |
| 9 | ERROR | 3.3.10 |
| 10 | COOKIE ECHO | 3.3.11 |
| 11 | COOKIE ACK | 3.3.12 |
| 14 | SHUTDOWN COMPLETE | 3.3.13 |
Note: Chunk types 12 and 13 are not used in this specification.
14.2. SCTP Chunk Parameter Type Registration
IANA maintains the SCTP Chunk Parameter Type registry.
14.2.1. Parameter Type Value Ranges
Parameter Type Field: 16-bit value (0-65535)
Allocation Policy:
- 0-32767: Defined parameter types
- 32768-49151: Reserved for IETF Review
- 49152-65535: Experimental and private use
14.2.2. Defined Parameter Types
Parameter types defined by this RFC:
| Type | Name | Reference |
|---|---|---|
| 5 | IPv4 Address | 3.3.2.1 |
| 6 | IPv6 Address | 3.3.2.1 |
| 7 | State Cookie | 3.3.3.1 |
| 8 | Unrecognized Parameters | 3.3.3.2 |
| 9 | Cookie Preservative | 3.3.2.1 |
| 11 | Host Name Address | 3.3.2.1 |
| 12 | Supported Address Types | 3.3.2.1 |
14.3. SCTP Error Cause Code Registration
IANA maintains the SCTP Error Cause Code registry.
14.3.1. Error Cause Code Value Ranges
Cause Code Field: 16-bit value (0-65535)
Allocation Policy:
- 0-32767: Defined cause codes
- 32768-49151: Reserved for IETF Review
- 49152-65535: Experimental and private use
14.3.2. Defined Error Cause Codes
Error cause codes defined by this RFC:
| Code | Name | Reference |
|---|---|---|
| 1 | Invalid Stream Identifier | 3.3.10.1 |
| 2 | Missing Mandatory Parameter | 3.3.10.2 |
| 3 | Stale Cookie Error | 3.3.10.3 |
| 4 | Out of Resource | 3.3.10.4 |
| 5 | Unresolvable Address | 3.3.10.5 |
| 6 | Unrecognized Chunk Type | 3.3.10.6 |
| 7 | Invalid Mandatory Parameter | 3.3.10.7 |
| 8 | Unrecognized Parameters | 3.3.10.8 |
| 9 | No User Data | 3.3.10.9 |
| 10 | Cookie Received While Shutting Down | 3.3.10.10 |
| 11 | Restart of an Association with New Addresses | 3.3.10.11 |
| 12 | User Initiated Abort | 3.3.10.12 |
| 13 | Protocol Violation | 3.3.10.13 |
14.4. SCTP Payload Protocol Identifiers
IANA maintains the SCTP Payload Protocol Identifier registry.
14.4.1. Protocol Identifier Value Range
Payload Protocol Identifier Field: 32-bit value (0-4294967295)
Purpose: Identifies upper layer protocol carried in DATA chunk, allows receiver to properly process payload, orthogonal to port numbers.
14.4.2. Registration Policy
Allocation:
- 0: Reserved (not used by SCTP)
- 1-65535: Standardized protocols (IETF Review)
- 65536-: First Come First Served
Registration Requirements: Protocol name, description, reference document.
14.4.3. Defined Protocol Identifiers
Examples of predefined protocol identifiers:
| ID | Protocol | Reference |
|---|---|---|
| 0 | reserved | - |
| 1 | IUA | RFC 4233 |
| 2 | M2UA | RFC 3331 |
| 3 | M3UA | RFC 4666 |
| 4 | SUA | RFC 3868 |
| 5 | M2PA | RFC 4165 |
14.5. Port Number Assignment
14.5.1. SCTP Port Number Registration
SCTP uses the same port number space as TCP and UDP but maintained independently.
IANA Responsibilities: Maintain SCTP port number registry, accept allocation requests, coordinate with TCP/UDP usage.
Port Number Ranges:
- 0-1023: System Ports (Well Known) - IETF Review required
- 1024-49151: User Ports (Registered) - IANA Review required
- 49152-65535: Dynamic/Private Ports - No registration required
14.5.2. Recommended Practice
Port Assignment Recommendations: If protocol supports both TCP and SCTP, use same port number; new protocols should specify transport protocol clearly.
14.6. Registration Update Process
14.6.1. Registering New Values
Process: Submit request to IANA, provide documentation, undergo review, IANA assigns value and updates registry.
14.6.2. Modifying Existing Registrations
Allowed: Update references, clarify descriptions, correct errors. Not Allowed: Change assigned values, redefine existing entries.
14.6.3. Deprecating Registrations
Mark as "deprecated" rather than delete, preserve historical record, note reason and alternatives.
Summary
IANA's role in SCTP protocol management: Registry maintenance, value allocation, documentation management, coordination.
Best Practices: Check IANA registries before using new types, use experimental ranges for experiments, standardized extensions require IETF review, maintain accurate registration information.