ENUM -- Telephone Number Mapping J. Livingood Working Group Comcast Internet-Draft B. Hoeneisen Expires: September 6, 2007 Switch A. Mayrhofer enum.at Mar 05, 2007 Guide and Template for IANA Registrations of Enumservices draft-ietf-enum-enumservices-guide-03 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 September 6, 2007. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract This document provides a guide to and template for the creation of new IANA registration of ENUM (E.164 Number Mapping) services. i It is also to be used for updates of existing IANA registrations. Livingood, et al. Expires September 6, 2007 [Page 1] Internet-Draft BCP Enumservice Registrations Mar 2007 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Enumservice Creation Cookbook . . . . . . . . . . . . . . . . 3 3.1. Preparation . . . . . . . . . . . . . . . . . . . . . . . 3 3.2. About Type Names . . . . . . . . . . . . . . . . . . . . . 3 3.3. About Subtypes . . . . . . . . . . . . . . . . . . . . . . 4 4. Required Sections and Information . . . . . . . . . . . . . . 5 4.1. Introduction (MANDATORY) . . . . . . . . . . . . . . . . . 5 4.2. ENUM Service Registration . . . . . . . . . . . . . . . . 5 4.3. Examples (MANDATORY) . . . . . . . . . . . . . . . . . . . 7 4.4. Implementation Recommendations / Notes (OPTIONAL) . . . . 7 4.5. Security Considerations (MANDATORY) . . . . . . . . . . . 8 4.6. IANA Considerations (MANDATORY) . . . . . . . . . . . . . 8 4.7. DNS Considerations (OPTIONAL) . . . . . . . . . . . . . . 8 4.8. Other Sections (OPTIONAL) . . . . . . . . . . . . . . . . 9 5. Revision of Pre-Existing Enumservice RFCs . . . . . . . . . . 9 6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6.1. Considerations regarding this Document . . . . . . . . . . 9 6.2. Enumservice Security Considerations Guideline . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 9.1. Normative References . . . . . . . . . . . . . . . . . . . 10 9.2. Informative References . . . . . . . . . . . . . . . . . . 10 Appendix A. XML2RFC Template for Enumservice Registration . . . . 11 Appendix B. Changes . . . . . . . . . . . . . . . . . . . . . . . 17 Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Intellectual Property and Copyright Statements . . . . . . . . . . 19 Livingood, et al. Expires September 6, 2007 [Page 2] Internet-Draft BCP Enumservice Registrations Mar 2007 1. Introduction This document provides a guide to and template for the creation of new IANA registrations of Enumservices. This document aims to enhance section 3 of RFC 3761 [2], where the registration procedure for Enumservices was initially documented at a high level. However, the IETF's ENUM Working Group has encountered an unnecessary amount of variation in the format of Enumservice drafts presented to the group. The ENUM Working Group's view of what particular fields and information are required and/or recommended has also evolved, and capturing these best current practices is helpful in both the creation of new registrations, as well as the revision or refinement of existing registrations. For the purpose of this document, 'registration document' and 'registration' refers to an Internet Draft proposing the IANA registration of an Enumservice following the procedures outlined above. 2. Terminology 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 [1]. 3. Enumservice Creation Cookbook 3.1. Preparation Before commencing work on a new Enumservice registration, the following should be considered: o Is there an existing Enumservice which could fulfill the desired functionality without overloading it? Check the IANA Enumservice registrations on . o Is there work in progress on a similar Enumservice? Check the mailing list archives on , and the Internet Drafts Archive on . 3.2. About Type Names Generally, the 'type' name of an Enumservice is REQUIRED to give a clear indication of what the Enumservice is about. Usually, an Enumservice falls under one of the following categories: Livingood, et al. Expires September 6, 2007 [Page 3] Internet-Draft BCP Enumservice Registrations Mar 2007 o "Protocol" Enumservices are exclusively tied to a specific protocol. Such Enumservices typically use that single protocol and it's respective Uniform Resource Identifier (URI) [5] scheme (sometimes including a secure variant), and SHOULD use the protocol name / URI scheme name as the 'type'. In case the secure variant has a different URI scheme / protocol name, the URI scheme name of the base protocol SHOULD be preferred. Examples of such Enumservices include 'sip' (RFC 3764) [6] and 'ldap' (RFC 4328) [7]. o "Application" Enumservices usually use the abstract application name as the Enumservice 'type'. The name of the actual protocol and URI scheme may differ from the 'type', but may also be identical (especially when application service location [8] is used). If application name and URI scheme name are identical, it is RECOMMENDED to use that name also as the Enumservice 'type'. In case the actual protocol / URI scheme differs from the application name, it is RECOMMENDED to use that application name as Enumservice 'type'. Examples of such Enumservices are 'web' and 'ft' (RFC 4002) [9] and 'pres' (RFC3953) [10]. o "Data Format" Enumservices typically refer to a specific data type or format, which may be addressed using one or more URI schemes and protocols. It is RECOMMENDED to use a well known name of the data type / format as the Enumservice 'type'. An example of such an Enumservice is 'vpim' (RFC 4238) [7] and 'vCard' [11] (work in progress). To avoid confusion, the name of an URI scheme MUST NOT be used as a type name for an Enumservice which is not specifically about the respective protocol / URI scheme - for example, the type name 'imap' would be inadequate for use in an Enumservice about Internet mapping services, because it corresponds to an existing URI scheme / protocol for something different. 3.3. About Subtypes An Enumservice may optionally use a "subtype" to further specify the service to which a ENUM record refers to. The following recommendations apply to such Enumservices: o Subtypes SHOULD NOT be used to curtail the negotiation capabilities of the protocol used to contact the referred URI, unless this limitation is specifically desired. If that is the case, authors MUST describe the limitation, the motivation for this, and discuss potential problems arising from this. Livingood, et al. Expires September 6, 2007 [Page 4] Internet-Draft BCP Enumservice Registrations Mar 2007 o If subtypes are defined, the minimum number SHOULD be two. The choice of just one possible subtype for a given type does not add any information when selecting a ENUM record, and hence can be left out completely. However, potential future expansion of a type towards several subtypes MAY justify the use of subtypes, even in the case just one is currently defined. o It is perfectly legal under a certain 'type' to mix the Enumservice without a subtype with Enumservices containing a subtype. In that case, however, the Enumservice with an empty subtype SHOULD be used to reflect the base service, while the other Enumservices SHOULD be used to reflect variants. 4. Required Sections and Information In addition to the typical sections required for an RFC as outlined in RFC 2223bis [3] (Instructions to RFC Authors), there are several sections which MUST appear in an IANA Registration for an Enumservice. These sections are, as follows, and SHOULD be in the same order. Appendix A contains a template which can be used to create Internet Drafts and RFC by means described on . This template contains a prototype for most of these sections. 4.1. Introduction (MANDATORY) An introductory section MUST be included. This section will explain, in plain English, the purpose of and intended usage of the proposed Enumservice registration. The Introduction SHOULD start with a short sentence about ENUM, introduce the protocol used in the Enumservice, and discuss the Enumservice as it refers from the E.164 number to the protocol or service. 4.2. ENUM Service Registration This section MUST be included in an Enumservice registration. In addition, where a given registration type has multiple subtypes, there MUST be a separate registration section for each subtype. The following lists the sections and order of an Enumservice Registration section. All types and subtypes SHOULD be listed in lower-case. Enumservice Name: Livingood, et al. Expires September 6, 2007 [Page 5] Internet-Draft BCP Enumservice Registrations Mar 2007 A short word or stub sentence describing this Enumservice. Often this is equivalent to the Enumservice Type (see below), however, capitalization may be different from it. e.g. "Foo" Enumservice Type: The type of the Enumservice. Often this is equivalent to the Enumservice Name (see above). e.g. "foo" For choosing a suitable type, see also Section 3.2. Enumservice Subtype: The Subtype of the Enumservice. e.g. "bar" Many Enumservices do not require a subtype; use "N/A" in this case. For choosing a suitable subtype, see also Section 3.3. URI Schemes: The URI Schemes, which are used with the Enumservice. e.g. "bar:", "sbar:" A URI scheme often matches the subtype (see above). Multiple URI schemes can be listed here if they are used for the same subtype, and provide almost identical functionality. Note well that a client cannot choose a specific ENUM record in a record set based on the URI scheme - the selection is only based on 'type' and 'subtype'. Functional Specification: e.g. This Enumservice indicates that the remote resource identified can be addressed by the associated URI scheme in order to foo the bar. Security Considerations: An internal reference to the 'Security Considerations' section of a given registration document. Livingood, et al. Expires September 6, 2007 [Page 6] Internet-Draft BCP Enumservice Registrations Mar 2007 e.g. "see Section 10" Intended Usage: One of "COMMON", "LIMITED USE" or "OBSOLETE", as defined in RFC 3761 [2] e.g. "COMMON" Author(s): The author(s) of the Enumservice registration. e.g. John Doe Any other information the author(s) deem(s) interesting: e.g. None 4.3. Examples (MANDATORY) This section MUST show one or more example(s) of the Enumservice registration, for illustrative purposes. The example(s) shall in no way limit the various forms that a given Enumservice may take, and this should be noted at the beginning of this section of the document. The example(s) MUST show the specific formatting of the intended NAPTRs RFC 3403 [4], including one or more NAPTR example(s), AND a brief textual description, consisting of one or more sentences written in plain English, explaining the various parts or attributes of the record(s). The example(s) SHOULD contain a brief description how a client supporting this Enumservice could behave, if that description was not already given in e.g. the Introduction. e.g. $ORIGIN 9.7.8.0.9.7.8.9.0.9.4.4.e164.arpa. @ IN NAPTR 100 10 "u" "E2U+foo:bar" "!^.*$!bar://example.com/!" . 4.4. Implementation Recommendations / Notes (OPTIONAL) If at all possible, recommendations that pertain to implementation and/or operations SHOULD be included. Such a section is helpful to someone reading a registration and trying to understand how best to use it to support their network or service. Livingood, et al. Expires September 6, 2007 [Page 7] Internet-Draft BCP Enumservice Registrations Mar 2007 4.5. Security Considerations (MANDATORY) A section explaining any potential security threats that are unique to the given registration MUST be included. This MUST also include any information about access to Personally Identifiable Information (PII). However, this section is not intended as a general security Best Current Practices (BCP) document and therefore it should not include general and obvious security recommendations, such as securing servers with strong password authentication. 4.6. IANA Considerations (MANDATORY) Describe the task IANA needs to fulfill processing the Enumservice registration document. e.g. This memo requests registration of the "foo" Enumservice with the subtype "bar" according to the definitions in this document and RFC3761 [2]. 4.7. DNS Considerations (OPTIONAL) In case the inclusion of protocols and URI schemes into ENUM specifically introduces new DNS issues, those MUST be described within this section. Such DNS issues include, but are not limited to: o Assumptions about the namespace below the owner of the respective NAPTR RRSet. o Demand to use DNS wildcards. o Incompatibility with DNS wildcards. o presence or absence of the respective NAPTR RRSet at particular levels in the DNS hierarchy (e.g. only for 'full' E.164 numbers, or number blocks only). o use of any RRs (especially non-NAPTR) within or beyond the e164.arpa namespace other than those needed to resolve the domain names that appear in the 'replacement' URI. Rationale: some ENUM services try to exploit side effects of the DNS that need to be explicitly discussed. Livingood, et al. Expires September 6, 2007 [Page 8] Internet-Draft BCP Enumservice Registrations Mar 2007 4.8. Other Sections (OPTIONAL) Other sections, beyond those required by the IETF and/or IANA, which are cited or otherwise referenced here, MAY be included in an Enumservice registration. These sections may relate to the specifics of the intended usage of the Enumservice registration and associated technical, operational, or administrative concerns. 5. Revision of Pre-Existing Enumservice RFCs Several Enumservice registrations, published via IETF RFCs, already exist at the time of the development of this document. The authors recommend that these existing registration documents SHOULD be reviewed and, where necessary and appropriate, MAY be revised in accordance with the recommendations contained herein. All future Enumservice registrations SHOULD follow the recommendations contained herein, where practical and applicable. 6. Security Considerations 6.1. Considerations regarding this Document Since this document does not introduce any technology or protocol, there are no security issues to be considered for this memo itself. However, this document provides general security considerations for Enumservice registrations, which are to be referenced from document defining or updating Enumservice registrations. 6.2. Enumservice Security Considerations Guideline Section 6 of RFC 3761 already outlines security considerations affecting ENUM as a whole. Enumservice registration documents do not need and SHOULD NOT repeat considerations already listed there, but they SHOULD include a reference to that section. ENUM refers to resources using preexisting URI schemes and protocols. Enumservice registration documents do not need and SHOULD NOT repeat security considerations affecting those protocols and URI schemes itself. However, in case that the inclusion of those protocols and URI schemes into ENUM specifically introduces new security issues, those issues MUST be lined out in the 'Security Considerations' section of the registration document. Livingood, et al. Expires September 6, 2007 [Page 9] Internet-Draft BCP Enumservice Registrations Mar 2007 7. IANA Considerations This document itself does not define a new protocol, and therefore has no considerations for IANA. However, it contains a proposal for the 'IANA Considerations' section of actual Enumservice registration documents in Appendix A. Note: Section 4.2 is just an example of an Enumservice registration. The Enumservice "foo" outlined there MUST NOT be registered by IANA unless this memo is to be published on April 1st. 8. Acknowledgements The authors wish to thank Peter Koch for his contribution to this document. 9. References 9.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Faltstrom, P. and M. Mealling, "The E.164 to Uniform Resource Identifiers (URI) Dynamic Delegation Discovery System (DDDS) Application (ENUM)", RFC 3761, April 2004. [3] Reynolds, J. and R. Braden, "Instructions to Request for Comments (RFC) Authors", draft-rfc-editor-rfc2223bis-08 (work in progress), July 2004. [4] Mealling, M., "Dynamic Delegation Discovery System (DDDS) Part Three: The Domain Name System (DNS) Database", RFC 3403, October 2002. 9.2. Informative References [5] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. [6] Peterson, J., "enumservice registration for Session Initiation Protocol (SIP) Addresses-of-Record", RFC 3764, April 2004. [7] Vaudreuil, G., "Voice Message Routing Service", RFC 4238, October 2005. Livingood, et al. Expires September 6, 2007 [Page 10] Internet-Draft BCP Enumservice Registrations Mar 2007 [8] Daigle, L. and A. Newton, "Domain-Based Application Service Location Using SRV RRs and the Dynamic Delegation Discovery Service (DDDS)", RFC 3958, January 2005. [9] Brandner, R., Conroy, L., and R. Stastny, "IANA Registration for Enumservice 'web' and 'ft'", RFC 4002, February 2005. [10] Peterson, J., "Telephone Number Mapping (ENUM) Service Registration for Presence Services", RFC 3953, January 2005. [11] Mayrhofer, A., "IANA Registration for vCard Enumservice", draft-ietf-enum-vcard-05 (work in progress), November 2006. Appendix A. XML2RFC Template for Enumservice Registration IANA Registration for Enumservice Foo MyOrganization
MyAddress MyCity MyZIP MyCountry Myphonenumber MyEmailAddress MyWebpage
Livingood, et al. Expires September 6, 2007 [Page 11] Internet-Draft BCP Enumservice Registrations Mar 2007 RAI ENUM -- Telephone Number Mapping Working Group ENUM foo bar This memo registers the Enumservice "foo" with subtype "bar" using the URI scheme "bar". This Enumservice is to be used to refer from an ENUM domain name to the foobar of the entity using the corresponding E.164 number. A Client can use information gathered from a record using this Enumservice to foo the bar.
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.
E.164 Number Mapping (ENUM) uses the Domain Name System (DNS) to refer from E.164 numbers to Uniform Resource Identifiers (URIs). To distinguish between different services for a single E.164 number, section 2.4.2 of RFC 3761 specifies 'Enumservices', which are to be registered with IANA according to section 3 Livingood, et al. Expires September 6, 2007 [Page 12] Internet-Draft BCP Enumservice Registrations Mar 2007 of RFC 3761 and RFC XXXX. The 'foo' protocol is specified in ... and provides ... The Enumservice specified in this document refers from an E.164 number to a foobar ... Clients use those foobars to foo the bar.
Enumservice Name: "foo" Enumservice Type: "foo" Enumservice Subtypes: "bar" URI Schemes: "bar" Functional Specification: This Enumservice indicates that the resource identified is a foobar ... Security Considerations: see Intended Usage: COMMON Author(s): MyName MySurname, <myEmail> Any other information the author(s) deem(s) interesting: None
Livingood, et al. Expires September 6, 2007 [Page 13] Internet-Draft BCP Enumservice Registrations Mar 2007 An example ENUM record referencing to "foo" could look like: $ORIGIN 9.7.8.0.9.7.8.9.0.9.4.4.e164.arpa. @ IN NAPTR 50 10 "u" "E2U+foo:bar" "!^.*$!bar://example.com/!" . ...
Implementers should consider that fooing the bar...
As with any Enumservice, the security considerations of ENUM itself (Section 6 of RFC 3761) apply.
Since ENUM uses DNS - a publicly available database - any information contained in records provisioned in ENUM domains must be considered public as well. Even after revoking the DNS entry and removing the referred resource, copies of the information could still be available. Information published in ENUM records could reveal associations between E.164 numbers and their owners - especially if URIs contain personal identifiers or domain names for which ownership information can be obtained easily. For example, the following URI makes it easy to guess the owner of an E.164 number as well as his location and association by just examining the result from the ENUM lookup: Livingood, et al. Expires September 6, 2007 [Page 14] Internet-Draft BCP Enumservice Registrations Mar 2007 http://sandiego.company.example.com/joe-william-user.vcf However, it is important to note that the ENUM record itself does not need to contain any personal information. It just points to a location where access to personal information could be granted. For example, the following URI only reveals the service provider hosting the vCard (who probably even provides anonymous hosting): http://anonhoster.example.org/file_adfa001.vcf ENUM records pointing to third party resources can easily be provisioned on purpose by the ENUM domain owner - so any assumption about the association between a number and an entity could therefore be completely bogus unless some kind of identity verification is in place. This verification is out of scope for this memo.
Users MUST therefore carefully consider information they provide in the resource identified by the ENUM record as well as in the record itself. Considerations could include serving information only to entities of the user's choice and/or limiting the comprehension of the information provided based on the identity of the requester. (modify as appropriate - more about the specific resource here)
This memo requests registration of the "foo" Enumservice with the subtype "bar" according to the template in of this document and RFC3761. ...
Livingood, et al. Expires September 6, 2007 [Page 15] Internet-Draft BCP Enumservice Registrations Mar 2007
This Enumservices does not introduce any new considerations for the DNS. ...
The international public telecommunication numbering plan ITU-T Figure 1 Livingood, et al. Expires September 6, 2007 [Page 16] Internet-Draft BCP Enumservice Registrations Mar 2007 Appendix B. Changes [RFC Editor: This section is to be removed before publication] draft-ietf-enum-enumservices-guide-03: o alex: moved terminology section o alex: removed note asking for feedback o bernie: added DNS consideration section o bernie: added Acknowledgements section o bernie: editorial stuff (nicer formating, fixing too long lines) o alex: added security considerations from vcard draft. draft-ietf-enum-enumservices-guide-02: o bernie: replaced numbers in examples by "Drama Numbers" o bernie: moved Change and Open Issues to Appendix. o bernie: major rewrite of section "6. Required Sections and Information" incl. separating explanations and examples. o bernie: removed section 7 (was just a repetition of referencing to template) o bernie: extended Appendix with Open Issues. draft-ietf-enum-enumservices-guide-01: o alex: added Security Considerations section for the doc itself o alex: added IANA Considerations section for the doc itself o alex: added cookbook idea Appendix C. Open Issues [RFC Editor: This section should be empty before publication] o Clarify Status of document. Is BCP adequate? o Clarify dependencies and collisions with RFC 3761. Should this document update RFC 3761? o Write something in the introduction about what the document does not intend (no guarantee for surviving in the ENUM WG, no change of the process itself). o Clarify IANA impact of this document. o Clarify whether experimental Enumservices should be described herein. o URL for template, so that it can be fetched without header-/ footer-lines of RFC. Livingood, et al. Expires September 6, 2007 [Page 17] Internet-Draft BCP Enumservice Registrations Mar 2007 Authors' Addresses Jason Livingood Comcast Cable Communications 1500 Market Street Philadelphia, PA 19102 USA Phone: +1-215-981-7813 Email: jason_livingood@cable.comcast.com URI: http://www.comcast.com/ Bernie Hoeneisen Switch Neumuehlequai 6 CH-8001 Zuerich Switzerland Phone: +41 44 268 1515 Email: hoeneisen@switch.ch, b.hoeneisen@ieee.org URI: http://www.switch.ch/ Alexander Mayrhofer enum.at GmbH Karlsplatz 1/9 Wien A-1010 Austria Phone: +43 1 5056416 34 Email: alexander.mayrhofer@enum.at URI: http://www.enum.at/ Livingood, et al. Expires September 6, 2007 [Page 18] Internet-Draft BCP Enumservice Registrations Mar 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). 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. Intellectual Property 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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Livingood, et al. Expires September 6, 2007 [Page 19]