Session Initiation Protocol (SIP) INFO Method and Package Framework
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From: The IESG <email@example.com> To: IETF-Announce <firstname.lastname@example.org> Cc: Internet Architecture Board <email@example.com>, RFC Editor <firstname.lastname@example.org>, sipcore mailing list <email@example.com>, sipcore chair <firstname.lastname@example.org> Subject: Protocol Action: 'Session Initiation Protocol (SIP) INFO Method and Package Framework' to Proposed Standard The IESG has approved the following document: - 'Session Initiation Protocol (SIP) INFO Method and Package Framework' <draft-ietf-sipcore-info-events-10.txt> as a Proposed Standard This document is the product of the Session Initiation Protocol Core Working Group. The IESG contact persons are Robert Sparks and Gonzalo Camarillo. A URL of this Internet Draft is: https://datatracker.ietf.org/doc/draft-ietf-sipcore-info-events/
Technical Summary This document defines a SIP method, INFO, along with a framework for the ways in which various applications can make use of this method. It obsoletes the previous definition of INFO, provided by RFC 2976, while including backwards-compatibility considerations that allow those applications based on RFC 2976 to continue to operate. Working Group Summary One of the recurring topics over the course of the development of a package mechanism for INFO was whether such a mechanism provides any true value. RFC 2976 originally defined the SIP INFO method in a scant 9 pages (including boilerplate). Over time, its use as a catch-all for non-standard user-to-user data became recognized as a key barrier to interoperability. For example, many vendors have defined their own, proprietary INFO-based mechanism for conveying DTMF ("TouchTone") information. However, none of these mechanisms have been published (in the IETF, in other standards bodies, or even in non-SDO documents), leading to severe fragmentation in the ability to convey this type of information. At the same time, many of the uses of INFO were recognized as being shortcuts to more appropriate and flexible mechanisms. For example, the conveyance of DTMF cited above is better suited to the mechanism defined in RFC 4733 when treated as an audio component, while the problem of general key-press conveyance is better handled by the mechanisms of RFC 4730. As a result of the foregoing, the working group spent significant discussion time over many years coming to agreement on whether it was more appropriate to fix INFO (by defining a registration mechanism for the ways in which it was used) or to deprecate it altogether (with the usage described in RFC 3398 being grandfathered as the sole legitimate usage). Although it required substantial consensus building and concessions by those more inclined to completely deprecate INFO, the eventual direction of the working group was to publish a framework for registration of INFO packages -- if for no other reason than to finally conclude the seven-year long argument and move on to other issues. Document Quality The document has been reviewed for quality by several SIPCORE participants during the Working Group Last Call period; an earlier version of the document received a particularly thorough review by Vijay Gurbani. It should be noted that the document itself does not directly describe a mechanism that can be implemented. It defines a framework that requires additional specification before it can be implemented. At the time of this publication request, no such specifications are under development within the IETF (even as individual documents); and the document shepherd is not aware of any such specifications under development outside the IETF.