IANA Registry for the Session Initiation Protocol (SIP) "Priority" Header Field
An IANA registry for the values of SIP's 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
ISO Plain Language
On this page
§1Why the Registry Was Needed
The SIP Priority header field was defined in RFC 3261 in a way that allowed values beyond those originally specified. However, no registry had been set up to keep track of additional values.
RFC 6878 updates RFC 3261 by defining a registry for values of that header field.
SIP's Priority header could have new values, but there was no official list of them. This RFC creates that list.
§2Initial Values and Registration Policy
The new sub-registry, named Priority Header Field Values, is part of the Session Initiation Protocol (SIP) Parameters registry page. Its initial values are non-urgent, normal, urgent, and emergency, each referenced to RFC 3261.
New values require IETF Review because their semantics could have architectural impact. The RFC advises people considering a new value to consider whether SIP Resource-Priority or another protocol is more appropriate.
The registry starts with four values: non-urgent, normal, urgent, and emergency. Adding another value needs IETF Review because it could affect how SIP is designed.
§3Security Considerations
The RFC states that this document has no impact on SIP security. Its purpose is administrative: it creates a registry and defines the policy for adding values.
This document organizes the header's values. The RFC says it does not affect SIP security.