dispatch R. Jesske Internet-Draft Deutsche Telekom Updates: RFC7976 (if approved) March 11, 2019 Intended status: Informational Expires: September 12, 2019 Update to Private Header Field P-Visited-Network-ID in Session Initiation Protocol (SIP) Requests and Responses draft-jesske-update-p-visited-network-01.txt Abstract The Third Generation Partnership Project (3GPP) has identified cases where the private header field P-Visited-Network-ID SIP private header extensions, which is defined in RFC 7315 and updated by RFC 7976, needs to be included in SIP requests and responses. This document updates RFC 7976, in order to allow inclusion of the P- Visited-Network-ID header field in responses. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on September 12, 2019. Copyright Notice Copyright (c) 2019 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 (https://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 Jesske Expires September 12, 2019 [Page 1] Internet-Draft Update P-visited-network March 2019 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Applicability of P-Visited-Network-ID in responses . . . . . 2 4. Security Considerations . . . . . . . . . . . . . . . . . . . 3 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction The Third Generation Partnership Project (3GPP) has identified cases where different Session Initiation Protocol (SIP) [RFC3261] private header extensions referred to as "P-" header fields, and defined in [RFC7315], need to be included in SIP requests and responses which is currently not allowed according to [RFC7315]. This document updates [RFC7315], to allow the inclusion of the affected "P-" header fields in such requests and responses. This document also makes updates for [RFC7976] to fix misalignments that occurred when [RFC7315] was updated for specific "P-" header fields which are mainly used in (and in most cases, only defined for) networks defined by the 3GPP. The updates defined in this document will not cause backward- compatibility problems in 3GPP networks which are using [TS.3GPP.24.229]. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. Applicability of P-Visited-Network-ID in responses In [RFC7976] section 3. "Updates to RFC 7315" the P-Visited-Network- ID header field was restricted to the following: The P-Visited- Network-ID header field can appear in all SIP methods except ACK, BYE, CANCEL, NOTIFY, PRACK, INFO, and UPDATE. This document allows the use of the P-Visited-Network-ID header field additionally within Responses as follows: Any SIP Response message, except for a 100 (Trying), MAY contain a P-Visited-Network-ID header field. The P- Jesske Expires September 12, 2019 [Page 2] Internet-Draft Update P-visited-network March 2019 Visited-Network-ID header field is not needed in the 100 (Trying) responses, since they are transmitted hop by hop, not end to end. 4. Security Considerations The security considerations for these "P-" header fields are defined in [RFC7315]. This specification allows some header fields to be present in messages where they were previously not allowed, and the security considerations and assumptions described in [RFC7315] (e.g., regarding only sending information to trusted entities) also apply to those messages. That does not cause any security issues, but implementors need to be aware that implementations may not have been updated according to this document, and take proper actions if a header field does not occur, in a message where it should occur or occurs in a message where it should not occur. The security and privacy considerations for the P-Visited-Network-ID header field are similar to those for the other SIP responses discussed in [RFC7315]. 5. Acknowledgments The author would like to acknowledge the constructive feedback provided by Michael Kreipl 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, DOI 10.17487/RFC3261, June 2002, . [RFC7315] Jesske, R., Drage, K., and C. Holmberg, "Private Header (P-Header) Extensions to the Session Initiation Protocol (SIP) for the 3GPP", RFC 7315, DOI 10.17487/RFC7315, July 2014, . [RFC7976] Holmberg, C., Biondic, N., and G. Salgueiro, "Updates to Private Header (P-Header) Extension Usage in Session Initiation Protocol (SIP) Requests and Responses", RFC 7976, DOI 10.17487/RFC7976, September 2016, . Jesske Expires September 12, 2019 [Page 3] Internet-Draft Update P-visited-network March 2019 [TS24-229] 3rd Generation Partnership Project, "3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3", TS 24.229, V 14.4.0, March 2017. Author's Address Roland Jesske Deutsche Telekom Heinrich-Hertz Str. 3-7 Darmstadt 64295 Germany Email: r.jesske@telekom.de URI: www.telekom.de Jesske Expires September 12, 2019 [Page 4]