Updated IANA Considerations for Diameter Command Code Allocations
Extracted elements (8)
The command code space was split into ranges with different allocation policies to align the extensibility rules for Diameter commands with those for Diameter application identifiers, allowing other SDOs to define new commands without requiring IETF consensus while still avoiding overloading of existing commands.
The prior RFC 3588 requirement for IETF consensus to define new Diameter commands caused other SDOs to define new applications on existing commands rather than requesting new command codes, leading to poor design choices and interoperability problems; this document corrects that incentive structure.
Command codes 16,777,214 and 16,777,215 (0xfffffe–0xffffff) are reserved for experimental and testing purposes only; no guarantee of interoperability between Diameter peers using experimental commands is made, per RFC 3692.
A request to IANA for a vendor-specific command code SHOULD include a reference to a publicly available specification that documents the command in sufficient detail to aid interoperability between independent implementations.
If the specification for a vendor-specific command code cannot be made publicly available, the request for a vendor-specific command code MUST include the contact information of persons and/or entities responsible for authoring and maintaining the command.
Diameter command codes 257, 258, 271, 274, 275, 280, and 282 are defined by RFC 3588 within the standard range (256–8,388,607) and assigned in Section 3.1 of that specification.
The Diameter Command Code namespace is split into four ranges: 0–255 reserved for RADIUS backward compatibility, 256–8,388,607 for permanent standard commands requiring IETF Review, 8,388,608–16,777,213 for vendor-specific codes allocated First Come First Served, and 16,777,214–16,777,215 reserved for experimental commands.
Delegating Diameter command code work to organizations outside the IETF means security reviews may be conducted differently; other organizations become responsible for the quality of the specifications they produce, and the DIME WG is aware of these risks.