A Clarification on the Use of Globally Routable User Agent URIs (GRUUs) in the SIP Event Notification Framework
RFC 7621
Document | Type |
RFC - Proposed Standard
(August 2015; No errata)
Updates RFC 6665
|
|
---|---|---|---|
Author | Adam Roach | ||
Last updated | 2018-12-20 | ||
Replaces | draft-roach-sipcore-6665-clarification | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Paul Kyzivat | ||
Shepherd write-up | Show (last changed 2015-04-29) | ||
IESG | IESG state | RFC 7621 (Proposed Standard) | |
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Ben Campbell | ||
Send notices to | (None) | ||
IANA | IANA review state | IANA OK - No Actions Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) A.B. Roach Request for Comments: 7621 Mozilla Updates: 6665 August 2015 Category: Standards Track ISSN: 2070-1721 A Clarification on the Use of Globally Routable User Agent URIs (GRUUs) in the SIP Event Notification Framework Abstract Experience since the publication of the most recent SIP Events framework (in July 2012) has shown that there is room for interpretation around the use of Globally Routable User Agent URIs in that specification. This document clarifies the intended behavior. This document updates RFC 6665. 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/rfc7621. Copyright Notice Copyright (c) 2015 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. Roach Standards Track [Page 1] RFC 7621 SIP Events GRUU Clarification August 2015 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Clarification of GRUU Handling . . . . . . . . . . . . . . . 2 3. Security Considerations . . . . . . . . . . . . . . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 5. Normative References . . . . . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction This document is intended to clarify a point of implementor confusion arising from lack of clarity in [RFC6665]. 2. Clarification of GRUU Handling The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Section 4.5.1 of [RFC6665] contains the following normative requirement on implementations: Notifiers MUST implement the Globally Routable User Agent URI (GRUU) extension defined in [RFC5627], and MUST use a GRUU as their local target. This allows subscribers to explicitly target desired devices. The second sentence of this paragraph attempted to set context for the normative statement: the reason GRUUs are required in this context is to allow you to send SUBSCRIBE or REFER requests to a specific user agent, with the target of the subscription request being something like an INVITE dialog on that device. Consequently, the requirement to include a GRUU as a local target was intended to apply not just to the local target for SUBSCRIBE-created dialogs, but to *all* dialogs, even those created by INVITE. This requirement has been interpreted in a variety of ways by implementors, so a clarification is in order. Discussion subsequent to the publication of [RFC6665] has highlighted obscure cases in which implementations might be notifiers in some contexts, but may not wish to act as notifiers in others. Under these narrow circumstances, the restriction described above is not necessary for dialogs about which the notifier will never accept subscriptions (although the use of GRUUs in such a context causes no harm, either). Roach Standards Track [Page 2] RFC 7621 SIP Events GRUU Clarification August 2015 This document updates [RFC6665] to clarify the actual requirements. The replacement text is as follows: Notifiers MUST implement the Globally Routable User Agent URI (GRUU) extension defined in [RFC5627]. Notifiers MUST use a GRUU as their local target for all dialog-forming methods and all target-refresh methods, except for those dialogs for which they will reject all subscription requests (implicit or explicit). ForShow full document text