Clarifications for When to Use the name-addr Production in SIP Messages
RFC 8217
Document | Type | RFC - Proposed Standard (August 2017; No errata) | |
---|---|---|---|
Author | Robert Sparks | ||
Last updated | 2018-12-20 | ||
Replaces | draft-sparks-sipcore-name-addr-guidance | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Brian Rosen | ||
Shepherd write-up | Show (last changed 2017-05-15) | ||
IESG | IESG state | RFC 8217 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Ben Campbell | ||
Send notices to | Brian Rosen <br@brianrosen.net> | ||
IANA | IANA review state | IANA OK - No Actions Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) R. Sparks Request for Comments: 8217 Oracle Updates: 3261, 3325, 3515, 3892, 4508, August 2017 5002, 5318, 5360, 5502 Category: Standards Track ISSN: 2070-1721 Clarifications for When to Use the name-addr Production in SIP Messages Abstract RFC 3261 constrained several SIP header fields whose grammar contains the "name-addr / addr-spec" alternative to use name-addr when certain characters appear. Unfortunately, it expressed the constraints with prose copied into each header field definition, and at least one header field was missed. Further, the constraint has not been copied into documents defining extension headers whose grammar contains the alternative. This document updates RFC 3261 to state the constraint generically and clarifies that the constraint applies to all SIP header fields where there is a choice between using name-addr or addr-spec. It also updates the RFCs that define extension SIP header fields using the alternative to clarify that the constraint applies (RFCs 3325, 3515, 3892, 4508, 5002, 5318, 5360, and 5502). 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 7841. 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/rfc8217. Sparks Standards Track [Page 1] RFC 8217 name-addr Clarifications August 2017 Copyright Notice Copyright (c) 2017 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 carefully, as they describe your rights and restrictions with respect 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Updates to RFC 3261 . . . . . . . . . . . . . . . . . . . . . 4 4. Updates to RFCs Defining SIP Extension Header Fields . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . 5 7. Normative References . . . . . . . . . . . . . . . . . . . . 5 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction [RFC3261] defines several header fields that contain URIs to allow both a form that contains the bare URI (addr-spec) and one that provides a name and the URI (name-addr). This subset, taken from the ABNF [RFC5234] specified in [RFC3261], shows the relevant part of the definition of the syntax of the "From" header field: From = ( "From" / "f" ) HCOLON from-spec from-spec = ( name-addr / addr-spec ) *( SEMI from-param ) name-addr = [ display-name ] LAQUOT addr-spec RAQUOT addr-spec = SIP-URI / SIPS-URI / absoluteURI The prose in Section 20.20 of [RFC3261], which discusses the "From" header field, constrains how the production may be used by saying: Even if the "display-name" is empty, the "name-addr" form MUST be used if the "addr-spec" contains a comma, question mark, or semicolon. Sparks Standards Track [Page 2] RFC 8217 name-addr Clarifications August 2017 Section 20.39 of [RFC3261], which discusses the "To" header field, contains no such constraining text. This constraint is specified slightly differently, but with the same intent, in the introduction to Section 20 of [RFC3261]: The Contact, From, and To header fields contain a URI. If the URI contains a comma, question mark or semicolon, the URI MUST be enclosed in angle brackets (< and >). Unfortunately, this can be read to only apply to the Contact, From, and To header fields, making it necessary to provide the constraint explicitly in the prose discussing any other header field using theShow full document text