A new Request for Comments is now available in online RFC libraries. RFC 7433 Title: A Mechanism for Transporting User-to-User Call Control Information in SIP Author: A. Johnston, J. Rafferty Status: Standards Track Stream: IETF Date: January 2015 Mailbox: alan.b.johnston@gmail.com, jay@humancomm.com Pages: 19 Characters: 45687 Updates/Obsoletes/SeeAlso: None I-D Tag: draft-ietf-cuss-sip-uui-17.txt URL: https://www.rfc-editor.org/info/rfc7433 There is a class of applications that benefit from using SIP to exchange User-to-User Information (UUI) data during session establishment. This information, known as call control UUI data, is a small piece of data inserted by an application initiating the session and utilized by an application accepting the session. The syntax and semantics for the UUI data used by a specific application are defined by a UUI package. This UUI data is opaque to SIP and its function is unrelated to any basic SIP function. This document defines a new SIP header field, User-to-User, to transport UUI data, along with an extension mechanism. This document is a product of the Call Control UUI Service for SIP Working Group of the IETF. This is now a Proposed Standard. STANDARDS TRACK: This document specifies an Internet Standards Track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the Official Internet Protocol Standards (https://www.rfc-editor.org/standards) for the standardization state and status of this protocol. Distribution of this memo is unlimited. This announcement is sent to the IETF-Announce and rfc-dist lists. To subscribe or unsubscribe, see https://www.ietf.org/mailman/listinfo/ietf-announce https://mailman.rfc-editor.org/mailman/listinfo/rfc-dist For searching the RFC series, see https://www.rfc-editor.org/search For downloading RFCs, see https://www.rfc-editor.org/rfc.html Requests for special distribution should be addressed to either the author of the RFC in question, or to rfc-editor@rfc-editor.org. Unless specifically noted otherwise on the RFC itself, all RFCs are for unlimited distribution. The RFC Editor Team Association Management Solutions, LLC