IANA Registry for the Session Initiation Protocol (SIP) "Priority" Header Field
updates
- rfc-3261 — SIP: Session Initiation Protocol
Extracted elements (5)
The IETF Review policy was selected over lighter-weight registration policies because new Priority values carry potential architectural implications. Documents contemplating new Priority values should consider whether SIP Resource-Priority (RFC 4412) or a different protocol would better meet their requirements.
This document updates RFC 3261 by establishing a formal registry for the Priority header field values originally defined in RFC 3261 Section 20.26, which lacked a registry despite being specified in a way that allows for new values.
Registration of new values in the 'Priority Header Field Values' registry requires 'IETF Review' as defined by RFC 5226. This policy was chosen over lighter-weight policies due to the potential architectural impact of semantics associated with new Priority values.
A new IANA sub-registry titled 'Priority Header Field Values' is added to the 'Session Initiation Protocol (SIP) Parameters' registry. Initial values are: non-urgent, normal, urgent, and emergency, all referencing RFC 3261.
This document has no impact on the security of the SIP protocol; its purpose is purely administrative in establishing an IANA registry for Priority header field values.