Session PEERing for Multimedia O. Lendl INTerconnect enum.at Internet-Draft August 2, 2006 Expires: February 3, 2007 Publishing Policies using the Domain Policy DDDS Application draft-lendl-speermint-technical-policy-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 February 3, 2007. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This documents contains the policy-type definition for "std" within the Domain Policy DDDS Application. Using this policy-type, service providers can announce to prospective callers which protocols (or protocol extensions) need to be supported to reach this destination network. Lendl Expires February 3, 2007 [Page 1] Internet-Draft Policy Publication August 2006 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . . 3 3. Naming Protocol Extensions . . . . . . . . . . . . . . . . . . 3 3.1. RFCs . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2. Internet Drafts . . . . . . . . . . . . . . . . . . . . . . 4 3.3. Other Standards . . . . . . . . . . . . . . . . . . . . . . 4 4. Policy-Type template . . . . . . . . . . . . . . . . . . . . . 4 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 9.1. Normative References . . . . . . . . . . . . . . . . . . . 6 9.2. Informative References . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7 Intellectual Property and Copyright Statements . . . . . . . . . . 8 Lendl Expires February 3, 2007 [Page 2] Internet-Draft Policy Publication August 2006 1. Introduction The domain policy DDDS application [2] defines a generic method how a domain owner may announce the conditions to accept incoming communications. This documents defines the policy-type for publishing a list of required standards (often protocol extensions) which a caller must support. The policy-type chosen for this application is "std". Rules using the the "std" policy-type refer to published and thus well-known rule-sets. These are thus "Publications" in the language of [2]. Two parties can thus independently start to support and require a standard and will interoperate without any coordination. The examples in the Domain Policy DDDS I-D use this policy-type. 2. Protocol Extensions Usually, protocols have built-in methods to signal support for extensions to the core protocol. Such negotiations happen inside the protocol and thus only after the connection has been established. If protocol extensions are not optional, but required by the receiving side, this can lead to the following unwanted effects: o Delay: If the sender side can fall back to a different protocol or delivery path than such an unsuccessful connection attempt costs time. o Layering problems: If the destination side requires special TLS or IPsec parameters for the connection to succeed, it cannot tell the sender side about these requirements within the protocol, as no connection can be established with having conveyed these parameters. o Extension naming: Negotiations within the protocol usually use IANA-assigned protocol identifiers. These might not be available for experimental extensions. The Domain Policy DDDS Application can be used to convey a list of required protocol extensions to any prospective sender out-of-band of the actual application protocol. 3. Naming Protocol Extensions The Domain Policy DDDS Application uses URIs as identifiers for Lendl Expires February 3, 2007 [Page 3] Internet-Draft Policy Publication August 2006 individual policy rules. This is a good fit as URIs are perfect to indicate standards. 3.1. RFCs According to RFC 2648 [1] IETF RFCs can be referenced by the URIs of the form "urn:ietf:rfc:". As an example, a record of $ORIGIN example.com @ IN NAPTR 10 50 "U" "D2P+SIP:std" ( "!^.*$!urn:ietf:rfc:3325!" . ) indicates that example.com expects incoming calls to use the SIP Asserted Identity standard to transmit caller ID data. 3.2. Internet Drafts RFC 2648 includes an URN definition for Internet Drafts as well. These look like "urn:ietf:id:". RFC 2648 lists "urn:ietf:id:ietf-urn-ietf-06" as an example. 3.3. Other Standards As a general rule, if the publishing organization has defined an URN schema for its documents, that should be used. If not, the location of the standard document on the official web-page can be used. 4. Policy-Type template Policy Type: "std" URI Scheme(s): Any URI is allowed. Functional Specification: The URI acts as an identifier of a standardization document which describes procedures that a sender needs to follow. Security considerations: None beyond the ones listed in [2] . Intended usage: COMMON Lendl Expires February 3, 2007 [Page 4] Internet-Draft Policy Publication August 2006 Author: Otmar Lendl 5. Examples The examples are for the SIP [4] peering case. To build complex examples, the policy-type "fed" as described in [3] is also used. o The carrier example.com only accepts SIP calls if a set of features is present, he might publish a policy like this: $ORIGIN example.com. ; order pref flags service regexp replacement IN NAPTR 10 10 "U" "D2P+SIP:std" "!^.*$!urn:ietf:rfc:3325!" . IN NAPTR 10 11 "U" "D2P+SIP:std" "!^.*$!urn:ietf:rfc:3326!" . o In this example the "example.com" also allows incoming connections as long they use the SIP remote party ID header. Calls according to federation rules are preferred. $ORIGIN example.com. IN NAPTR 10 50 ( ; order priority "U" "D2P+SIP:fed" ; flags service "!^.*$!http://sipxconnect.example.org/!" . ; regexp repl ) IN NAPTR 20 10 ( ; order priority "U" "D2P+SIP:std" ; flags service "!^.*$!urn:ietf:id:ietf-sip-privacy-02!" . ; regexp repl ) 6. Security Considerations The publishing of the access policy via the DNS RR described in this draft will reduce the amount of unwanted communication attempts, as all well-meaning clients will follow them, but these records cannot substitute measures to actually enforce the published policy. 7. IANA Considerations This document registers the policy-type "std" for the domain policy DDDS application. 8. Acknowledgements Lendl Expires February 3, 2007 [Page 5] Internet-Draft Policy Publication August 2006 The author would like to thank Alexander Mayrhofer and Michael Haberler for their contributions. 9. References 9.1. Normative References [1] Moats, R., "A URN Namespace for IETF Documents", RFC 2648, August 1999. [2] Lendl, O., "The Domain Policy DDDS Application", draft-lendl-domain-policy-ddds-00 (work in progress), February 2006. 9.2. Informative References [3] Lendl, O., "A Federation based VoIP Peering Architecture", draft-lendl-speermint-federations-02 (work in progress), August 2006. [4] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002. Lendl Expires February 3, 2007 [Page 6] Internet-Draft Policy Publication August 2006 Author's Address Otmar Lendl enum.at GmbH Karlsplatz 1/9 Wien A-1010 Austria Phone: +43 1 5056416 33 Email: otmar.lendl@enum.at URI: http://www.enum.at/ Lendl Expires February 3, 2007 [Page 7] Internet-Draft Policy Publication August 2006 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. 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. Disclaimer of Validity 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 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. Copyright Statement Copyright (C) The Internet Society (2006). 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. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Lendl Expires February 3, 2007 [Page 8]