SIPPING D. York Internet-Draft Voxeo Intended status: Informational February 18, 2008 Expires: August 21, 2008 P-Charge-Info - A Private Header (P-Header) Extension to the Session Initiation Protocol (SIP) draft-york-sipping-p-charge-info-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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 21, 2008. Copyright Notice Copyright (C) The IETF Trust (2008). Abstract This document describes 'P-Charge-Info', a private Session Initiation Protocol (SIP) header (P-header) used by a number of equipment vendors and carriers to convey simple billing information. York Expires August 21, 2008 [Page 1] Internet-Draft P-Charge-Info, a SIP Private Header February 2008 Table of Contents 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Requirements Language . . . . . . . . . . . . . . . . . . . . . 3 3. The P-Charge-Info Header . . . . . . . . . . . . . . . . . . . 4 3.1. Applicability Statement for the P-Charge-Info header . . . 4 3.2. Usage of the P-Charge-Info header . . . . . . . . . . . . . 4 3.2.1. Procedures at the UA . . . . . . . . . . . . . . . . . 4 3.2.2. Procedures at the Proxy . . . . . . . . . . . . . . . . 4 3.3. Examples of Usage . . . . . . . . . . . . . . . . . . . . . 4 4. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 5 Intellectual Property and Copyright Statements . . . . . . . . . . 6 York Expires August 21, 2008 [Page 2] Internet-Draft P-Charge-Info, a SIP Private Header February 2008 1. Overview In certain network configurations, it is desirable to decouple the Caller ID from the number used for billing purposes. This document describes the current usage of 'P-Charge-Info', a private SIP header, to provide simple billing information and requests the registration of this header with IANA as required by section 4.1 of RFC 3427. In a typical configuration, "Caller ID" is derived from one of the following SIP headers: o Remote-Party-ID o P-Asserted-Identity o From (in the absence of the other two) This number is typically presented to the receiving UA where it is usually displayed for the end user. It is also typically used for billing purposes by the network entities involved in carrying the session. However, in a distributed environment the "Caller ID" presented to the receiving UA may not reflect the actual reality of the underlying network in terms of costs incurred on the PSTN. This may result in excessive charging of one carrier by another based on the erroneous assumption that the call was originating from a different point on the PSTN. There exists a need for a way to pass an additional billing identifier that can be used between network entities in order to correctly bill for services. At least one equipment provider, Sonus Networks, and several carriers have begun using the "P-Charge-Info" header as a simple mechanism to exchange this billing identifier. It should be noted that the 3GPP has also recognized the need for such a billing identifier and in section 4.6 of RFC 3455 established a SIP P-Header, "P-Charging-Vector", to provide similar information. This header, though, is designed for use within 3GPP environments and includes more information than is required in many simpler environments. 2. Requirements Language 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 RFC 2119. York Expires August 21, 2008 [Page 3] Internet-Draft P-Charge-Info, a SIP Private Header February 2008 3. The P-Charge-Info Header 3.1. Applicability Statement for the P-Charge-Info header [Information to be completed.] 3.2. Usage of the P-Charge-Info header The P-Charge-Info header is used to convey information related to billing record for a particular call. The P-Charge-Info header is typically inserted by the SIP proxy on the originating network. 3.2.1. Procedures at the UA This document does not specify any procedure at the UA with regard to the P-Charge-Info header. UAs need not understand this header. 3.2.2. Procedures at the Proxy [Information to be completed.] 3.3. Examples of Usage [Information to be completed.] 4. Formal Syntax The Private Header specified in this document is described in both prose and an augmented Backus-Naur Form (BNF) defined in RFC 2234. Further, several BNF definitions are inherited from SIP and are not repeated here. Implementors need to be familiar with the notation and contents of SIP [1] and RFC 2234 [3] to understand this document. They syntax of the P-Charge-Info header is described as follows: [Information to be completed.] 5. IANA Considerations This document defines a private SIP extension header field (beginning with the prefixe "P-"). The extension is registered as a private extension field: RFC Number: RFCXXXX [Note to IANA: Fill in with the RFC number of this specification. York Expires August 21, 2008 [Page 4] Internet-Draft P-Charge-Info, a SIP Private Header February 2008 Header Field Name: P-Charge-Info Compact Form: none 6. Security Considerations Given that the information contained in the P-Charge-Info header will be used for billing purposes the proxies that share this information MUST have a trust relationship. If an untrusted entity were inserted between the trusted entities, it could potentially interfere with the billing records for the call. If the SIP connections are not made over a private WAN, a mechanism for securing the confidentiality and integrity of the SIP connection should be used to protect the information. Author's Address Dan York Voxeo Corporation Burlington, VT USA Phone: +1-407-455-5859 Email: dyork@voxeo.com URI: http://www.voxeo.com/ York Expires August 21, 2008 [Page 5] Internet-Draft P-Charge-Info, a SIP Private Header February 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 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The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). York Expires August 21, 2008 [Page 6]