IANA Registry for the Session Initiation Protocol (SIP) "Priority" Header Field
Creates an IANA registry for the values of the SIP Priority header field.
Roach, A.B., "IANA Registry for the Session Initiation Protocol (SIP) "Priority" Header Field", RFC 6878, DOI 10.17487/RFC6878, March 2013, <https://www.rfc-editor.org/info/rfc6878>.
@misc{rfc6878,
series = {Request for Comments},
number = 6878,
howpublished = {RFC 6878},
publisher = {RFC Editor},
doi = {10.17487/RFC6878},
url = {https://www.rfc-editor.org/info/rfc6878},
author = {A.B. Roach},
title = {{IANA Registry for the Session Initiation Protocol (SIP) "Priority" Header Field}},
pagetotal = 3,
year = 2013,
month = mar,
} RFC text
Contents
Internet Engineering Task Force (IETF) A.B. Roach
Request for Comments: 6878 Mozilla
Updates: 3261 March 2013
Category: Standards Track
ISSN: 2070-1721
IANA Registry for the Session Initiation Protocol (SIP)
"Priority" Header Field
Abstract
This document defines a new IANA registry to keep track of the values
defined for the Session Initiation Protocol (SIP) "Priority" header
field. It updates RFC 3261.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6878.
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
1. Introduction
This document defines a new IANA registry to keep track of the values
defined for the Session Initiation Protocol (SIP) "Priority" header
field. This header field was defined in [RFC3261], Section 20.26.
It was clearly specified in a way that allows for the creation of new
values beyond those originally specified; however, no registry has
been established for it.
2. IANA Considerations
This document adds a new sub-registry, "Priority Header Field
Values", to the "Session Initiation Protocol (SIP) Parameters"
registry page. Its format and initial values are as shown in the
following table:
+------------+-----------+
| Priority | Reference |
+------------+-----------+
| non-urgent | RFC 3261 |
| normal | RFC 3261 |
| urgent | RFC 3261 |
| emergency | RFC 3261 |
+------------+-----------+
The policy for registration of values in this registry is "IETF
Review" as that term is defined by [RFC5226]. This policy was chosen
over lighter-weight policies due the potential architectural impact
of the semantics associated with new values. Efforts contemplating
adding a Priority value should consider whether the SIP Resource-
Priority [RFC4412] or even a different protocol would be more
appropriate for achieving their requirements.
3. Security Considerations
This document does not have any impact on the security of the SIP
protocol. Its purpose is purely administrative in nature.
4. References
4.1. Normative References
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
June 2002.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
4.2. Informative References
[RFC4412] Schulzrinne, H. and J. Polk, "Communications Resource
Priority for the Session Initiation Protocol (SIP)",
RFC 4412, February 2006.
Author's Address
Adam Roach
Mozilla
Dallas, TX
US
EMail: adam@nostrum.com
AI ELI5
On this page
§1Introduction
The SIP Priority header field was defined in Section 20.26 of RFC 3261. It was specified so that new values could be created, but no registry had been established. This document defines one.
People could invent new priority words, but nobody kept a list. Now there is one.
§2The New Registry
The sub-registry "Priority Header Field Values" is added to the "Session Initiation Protocol (SIP) Parameters" page. Its initial values, all referencing RFC 3261, are non-urgent, normal, urgent and emergency.
The registration policy is "IETF Review" from RFC 5226, chosen over lighter policies because new values could affect the architecture. Anyone considering a new value should ask whether SIP Resource-Priority (RFC 4412) or a different protocol would fit better.
The list starts with four words. To add a fifth, a group of experts must agree, and you should check whether another tool already does the job.
- non-urgentRFC 3261 — Initial registry value.
- normalRFC 3261 — Initial registry value.
- urgentRFC 3261 — Initial registry value.
- emergencyRFC 3261 — Initial registry value.
§3Security Considerations
The document has no impact on the security of SIP. Its purpose is purely administrative in nature: it records existing values and sets a registration policy.
It only starts a list, so it changes nothing about safety.