DISPATCH J. Haluska Internet-Draft Telcordia Intended status: Informational February 16, 2010 Expires: August 20, 2010 The Need to Convey Carrier Selection Information in SIP draft-haluska-dispatch-csi-needed-00 Abstract This draft documents a need for the ability to signal Carrier Selection Information, which identifies how the carrier chosen for a call was selected, using SIP, and identifies a documented though not yet standardized mechanism which addresses this need. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on August 20, 2010. Copyright Notice Copyright (c) 2010 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 Haluska Expires August 20, 2010 [Page 1] Internet-Draft Carrier Selection Information Needed February 2010 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 BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 4 3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6.1. Normative References . . . . . . . . . . . . . . . . . . . 8 6.2. Informative References . . . . . . . . . . . . . . . . . . 8 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 9 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 10 Haluska Expires August 20, 2010 [Page 2] Internet-Draft Carrier Selection Information Needed February 2010 1. Introduction This draft documents the need for the ability to signal Carrier Selection Information, which identifies how the carrier chosen for a call was selected, using SIP, and identifies a documented though not yet standardized mechanism which addresses this need. Haluska Expires August 20, 2010 [Page 3] Internet-Draft Carrier Selection Information Needed February 2010 2. Problem Statement In the PSTN, Interexchange Carriers (IXCs) provide services including routing calls between different networks. In North America, subscribers can presubscribe to a particular IXC to handle calls by default. The IXC may be selected by other means. For example, the caller may dial a specific prefix identifying the desired IXC. When calls involving IXCs are made, it is required to record not only the IXC used for the call, but also the method by which that IXC was selected. Thus, this information needs to be conveyed in signaling. In ISUP this is conveyed using the Carrier Selection Information (CSI) parameter. Services currently implemented in the PSTN including Operator Services and Directory Assistance make use of the ISUP CSI parameter, e.g. for usage collection purposes. Such services are migrating to SIP based platforms, and the need for exchanging this information in signaling still exists. Current SIP-ISUP interworking standards do not specify a SIP mapping for the CSI parameter. Thus, when interworking from ISUP to SIP, the CSI parameter is carried in an encapsulated ISUP message in a MIME body. For SIP originated calls, there is currently no standardized way to carry this information. The "dai" tel URI parameter described in [I-D.draft-yu-tel-dai-08] is intended to convey this information in SIP. This parameter, if standardized, would provide a mechanism allowing for the exchange of this information using SIP. Haluska Expires August 20, 2010 [Page 4] Internet-Draft Carrier Selection Information Needed February 2010 3. Conclusion In environments such as the North American PSTN where carrier selection is implemented, there is a need to convey how the chosen carrier was selected. This information is still needed going forward using SIP. The "DAI" parameter defined in [I-D.draft-yu-tel-dai-08] can be used to exchange this information. Haluska Expires August 20, 2010 [Page 5] Internet-Draft Carrier Selection Information Needed February 2010 4. IANA Considerations This memo includes no request to IANA. Haluska Expires August 20, 2010 [Page 6] Internet-Draft Carrier Selection Information Needed February 2010 5. Security Considerations There are no security considerations associated with this document. Haluska Expires August 20, 2010 [Page 7] Internet-Draft Carrier Selection Information Needed February 2010 6. References 6.1. Normative References 6.2. Informative References [I-D.draft-yu-tel-dai-08] Yu, J., Hancock, D., and F. Andreason, "DAI Parameter for the "tel" URI", 2009. Haluska Expires August 20, 2010 [Page 8] Internet-Draft Carrier Selection Information Needed February 2010 Appendix A. Acknowledgements The author would like to thank Martin Dolly, Gary Munson, and the members of the Operator Services Technical Forum. Haluska Expires August 20, 2010 [Page 9] Internet-Draft Carrier Selection Information Needed February 2010 Author's Address John Haluska Telcordia 331 Newman Springs Road Red Bank, NJ 07701 USA Phone: Email: jhaluska@telcordia.com Haluska Expires August 20, 2010 [Page 10]