INTERNET DRAFT Donald E. Eastlake 3rd Motorola Expires April 2003 October 2002 DNS SRV Location of Higher Level Services Status of this Memo Distribution of this document is unlimited. Comments should be sent to the authors or the IETF TRADE working group . This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC 2026. 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. Copyright Notice Copyright (C) 2002, The Internet Society. All Rights Reserved. Abstract DNS naming conventions specified in RFC 2782 are extended to higher level services and a registry created for the tokens used. D. Eastlake [Page 1] INTERNET-DRAFT SRV Location of Higher Level Serives October 2002 Table of Contents Status of this Memo........................................1 Copyright Notice...........................................1 Abstract...................................................1 Table of Contents..........................................2 1. Introduction............................................3 2. Specification...........................................3 3. International Considerations............................4 4. IANA Considerations.....................................4 5. Security Considerations.................................4 Normative References.......................................5 Informative References.....................................5 Authors Address............................................6 Full Copyright Statement...................................7 File name and Expiration...................................7 D. Eastlake [Page 2] INTERNET-DRAFT SRV Location of Higher Level Serives October 2002 1. Introduction RFC 2782 specifies a DNS SRV Resource Record for the location of services. In addition, it provides a DNS naming convention for the DNS nodes at which such SRV RRs are stored. That is the form _Service._Proto.name.example as the name of the DNS node at which SRV RRs would be stored for obtaining the "Service" from "name.example". While there are a variety of means for locating higher level application services, some such services may wish to use the SRV RR. Such higher level services would, typically, be provided over the sorts of services that the RFC 2782 syntax is designed to speicfy. This document extends that syntax so that higher level protocols can be specified. 2. Specification SRV RRs can be stored at nodes with names of the following form _Higher._Service._Proto.name.example For example _iotp._http._tcp.example.net. The definition of the "_Proto" DNS label is the same as in RFC 2782. For the use described in this document, the "_Service" DNS label is a port specifying token registered with IANA in Assigned Numbers (such as http or ldap), prefixed with an underscore character. The DNS label "_Higher" is a token consisting from 2 to 12 ASCII letters and digits, registered as provided in Section 4 below, and prefixed with an underscore character. Higher level protocols sometimes have a number of services. To minimize the burden on the registration authority and maximize convenience to the protocol specifier, "Higher" may also consist of a token as registered hereunder followed by a hyphen character, followed by any characters allowed in connection with location of the higher level service. For example _xkms-xkiss-soap._http._tcp.example.org. Neither this specification nor registration hereunder is intended to imply over what services or protocols a higher level service can be used. Such limitations are specified in connection with that higher level service. For example, you need to look at the IOTP related specification for any information as to whether _iotp._smtp._sctp.foo.example could be useful. D. Eastlake [Page 3] INTERNET-DRAFT SRV Location of Higher Level Serives October 2002 Due to the case insensitive nature of DNS labels [RFC 1035], all of "_Higher", "_Service", and "_Proto" are case insensitive. 3. International Considerations The fully qualified DNS names discussed in this document and the Higher, Service, and Proto tokens appearing therein will normally be program generated and not seen by users. Thus no internationalization provisions are made. 4. IANA Considerations Upon approval by the IESG of the document, IANA will maintain a registry of higher level application designating tokens for use as specified in Section 2 above. The initial contents of the registry will be the two tokens IOTP - [RFC 2801] XKMS - [XML XKMS] The requirement for the registration of additional tokens is the documentation of each in an RFC or a similar free publicly accessible and reproducable document. To minimize the burden on the registry maintainer and maximize interoperability and convenience for the protocol specifier, such registration is to be taken as automatically incorporating later free publicly accessible and reproducable versions or amendments to the initial registration basis document by the entity with change control over the higher level service specification. To the extend reasonable, only a single token should be registered for a family of related higher level protocols or protocol versions that are under common control. The mechanism specified in Section 2 for extending such a token should be used, where needed, to distinguish variations for location purposes. Registration, control, and documentation of a higher level service token's extensions is not the concern of IANA unless an IESG approved RFC creates an IANA registration for that token's extenstions. 5. Security Considerations The security considerations as essentially the same as in RFC 2782. D. Eastlake [Page 4] INTERNET-DRAFT SRV Location of Higher Level Serives October 2002 Normative References [RFC 1035] - "Domain names - Implementation and Specification", Paul Mockapetris, November 1987. [RFC 2782] - "A DNS RR for specifying the location of services (DNS SRV)", A. Gulbrandsen, P. Vixie, L. Esibov, February 2000. Informative References [RFC 2801] - "Internet Open Trading Protocol - IOTP Version 1.0", D. Burdett, April 2000. [XML XKMS] - "XML Key Management Specification (XKMS 2.0)", Phillip Hallam-Baker, August 2002, D. Eastlake [Page 5] INTERNET-DRAFT SRV Location of Higher Level Serives October 2002 Authors Address Donald E. Eastlake 3rd Motorola 155 Beaver Street Milford, MA 01757 USA Phone: +1-508-851-8280 (w) +1-508-634-2066 (h) Email: Donald.Eastlake@motorola.com D. Eastlake [Page 6] INTERNET-DRAFT SRV Location of Higher Level Serives October 2002 Full Copyright Statement Copyright (c) 2002 The Internet Society, All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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. File name and Expiration This file is draft-ietf-trade-srv-higher-services-00.txt. It expires April 2003. D. Eastlake [Page 7]