ENUM -- Telephone Number Mapping B. Hoeneisen Working Group Swisscom Internet-Draft A. Mayrhofer Updates: 3762, 3764, 3953, 4143, enum.at 4002, 4238, 4355, 4415, 4769, Feb 15, 2009 4969, 4979, 5028 (if approved) Intended status: Standards Track Expires: August 19, 2009 Update of legacy IANA Registrations of Enumservices draft-ietf-enum-enumservices-transition-00 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and 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 19, 2009. Copyright Notice Copyright (c) 2009 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 (http://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. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 1] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Abstract This document specifies a revision of all Enumservices that have been registered at IANA under the nowadays obsolete regime of [RFC3761]. It mainly adds the new fields to the IANA Registration Template as specified in [I-D.ietf-enum-enumservices-guide], and makes at the same time some corrections of editorial nature. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. IESG Actions . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 4.1. Enumservice Registrations . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 30 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 30 7. Normative References . . . . . . . . . . . . . . . . . . . . . 30 Appendix A. Former Content of the IANA Repository . . . . . . . . 32 Appendix B. Document Changelog . . . . . . . . . . . . . . . . . 32 Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . . 33 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 33 Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 2] Internet-Draft Update legacy Enumservice Registrations Feb 2009 1. Introduction [I-D.ietf-enum-enumservices-guide] has obsoleted the IANA registration section of [RFC3761]. In the IANA registry for Enumservices, there are several entries that had been made under RFC 3761 regime. Those do not conform to the new guidelines as specified in [I-D.ietf-enum-enumservices-guide]. To ensure consistency among the Enumservice registrations, the document adds the new fields to the existing IANA registrations and makes some editorial corrections at the same time. However, this document does only add the missing fields from the IANA Registration Template as specified in the IANA Considerations of [I-D.ietf-enum-enumservices-guide], but does not complete the (nowadays) missing sections of the corresponding Registration Documents. These documents have to be revised in order to conform with the new regime for Enumservice registrations as specified in [I-D.ietf-enum-enumservices-guide]. This document updates the following RFCs: o [RFC3762] o [RFC3764] o [RFC3953] o [RFC4143] o [RFC4002] o [RFC4238] o [RFC4355] o [RFC4415] o [RFC4769] o [RFC4969] o [RFC4979] o [RFC5028] o [I-D.ietf-enum-calendar-service] 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 [RFC2119]. 3. IESG Actions According to [RFC3761], any Enumservice registration had to be published as RFC on the Standards Track, Experimental RFC, or as a BCP. [I-D.ietf-enum-enumservices-guide] no longer has this Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 3] Internet-Draft Update legacy Enumservice Registrations Feb 2009 requirement, i.e. Expert Review and Specification Required are sufficient. Accoring to the rules outlined in RFC ????, revisions of standards track documents can not be downgraded without IESG action. Therefore, with approval of this document, the IESG declares the following documents as downgraded, so that they can be revised according to the rules set out in [I-D.ietf-enum-enumservices-guide] (without the need for another standards track RFC): [RFC3762], [RFC3764], [RFC3953], [RFC4143], [RFC4002], [RFC4238], [RFC4355], [RFC4415], [RFC4769], [RFC4969], [RFC4979], [RFC5028], and [I-D.ietf-enum-calendar-service]. 4. IANA Considerations 4.1. Enumservice Registrations IANA are to replace all the existing Enumservice Registrations as follows; as per [I-D.ietf-enum-enumservices-guide] these are in the form of XML chunks: [Note for RFC Editor: Please replace any instance of RFCTHIS with the RFC number of this document before publication] Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 4] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common email mailto mailto This Enumservice indicates that the resource can be addressed by the associated URI in order to send an email. See , Section 6. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 5] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common ems mailto mailto This Enumservice indicates that the resource identified by the associated URI is capable of receiving a message using an email protocol. EMS content is sent over SMTP using the format specified by TS 23.140 [15] Section 8.4.4 and TS 26.140 [16] Section 4, as an MMS message. Within such a message, EMS content is carried as either a text or application/octet-stream MIME sub-part (see TS 26.140 [16], Section 4.1). For references see . There are no specific security issues with this Enumservice. However, the general considerations of Section 6 of apply. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 6] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common ems tel tel This Enumservice indicates that the resource identified by the associated URI is capable of receiving a message using the Enhanced Message Service (EMS) [14] (For reference see ). There are no specific security issues with this Enumservice. However, the general considerations of Section 6 of apply. COMMON (updated by RFCTHIS) Note that an indication of EMS can be taken as implying that the recipient is capable of receiving SMS messages at this address as well. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 7] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Subset fax tel tel This Enumservice indicates that the resource identified by the associated URI is capable of being contacted to provide a communication session during which facsimile documents can be sent. A client selecting this NAPTR will have support for generating and sending facsimile documents to the recipient using the PSTN session and transfer protocols specified in [12] and [13] in - in short, they will have a fax program with a local or shared PSTN access over which they can send faxes. See , Section 6. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 8] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Subset ft ftp ftp This Enumservice indicates that the resource identified by the associated URI is a file service from which a file or file listing can be retrieved. See , Section 5. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 9] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Protocol-Based h323 h323 See , Section 3. See , Section 5. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 10] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Data Type-Based ical access http, https This Enumservice indicates that the resource identified is a URI used for Internet Calendaring which is available to access a user's calendar (for example free/busy status). Supported URI Schemes are 'http:' or 'https:' URIs for the CalDAV [7] protocol. See , Section 3. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 11] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Data Type-Based ical sched mailto, http, https This Enumservice indicates that the resource identified is a URI used for scheduling using Internet Calendaring. Supported URI Schemes are the 'mailto:' URI for the iMIP [6] protocol, and 'http:' or 'https:' URIs for a planned scheduling extension [15] to the CalDAV [7] protocol. See , Section 3. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 12] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Subset ifax mailto mailto See , Section 1. See , Section 3. COMMON (updated by RFCTHIS) The URI Scheme is 'mailto' because facsimile is a profile of standard Internet mail and uses standard Internet mail addressing. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 13] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common im im This Enumservice indicates that the resource identified is an 'im:' URI. The 'im:' URI scheme does not identify any particular protocol that will be used to handle instant messaging receipt or delivery, rather the mechanism in RFC3861 [4] is used to discover whether an IM protocol supported by the party querying ENUM is also supported by the target resource. See , Section 3. COMMON (updated by RFCTHIS) Application-Based, Common mms mailto mailto This Enumservice indicates that the resource identified by the associated URI is capable of receiving a message using an email protocol. MMS messages are sent over SMTP using the format specified by TS 23.140 [15] Section 8.4.4 and TS 26.140 [16] Section 4. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 14] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Within and between MMS Environments (MMSE, network infrastructures that support the MultiMedia Service), other pieces of state data (for example, charging-significant information) are exchanged between MMS Relay Servers. Thus, although these servers use SMTP as the "bearer" for their application exchanges, they map their internal state to specialized header fields carried in the SMTP message exchanges. The header fields used in such MMSE are described in detail in [17]. For references see . There are no specific security issues with this Enumservice. However, the general considerations of Section 6 of apply. COMMON (updated by RFCTHIS) The MMS Architecture describes an interface between the MMSE and "legacy messaging systems" (labelled as MM3) which accepts "standard" SMTP messages. Thus although the MMS Relay Server that supports this interface appears as a standard SMTP server from the perspective of an Internet-based mail server, it acts as a gateway and translator, adding the internal state data that is used within and between the MMS Environments. This mechanism is described in [17], which also includes references to the specifications agreed by those bodies responsible for the design of the MMS. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 15] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common mms tel tel This Enumservice indicates that the resource identified by the associated URI is capable of receiving a message using the Multimedia Messaging Service (MMS) [15]. For references see . There are no specific security issues with this Enumservice. However, the general considerations of Section 6 of apply. COMMON (updated by RFCTHIS) Note that MMS can be used as an alternative to deliver an SMS RP- DATA RPDU if, for example, the SMS bearer is not supported. If an entry includes this Enumservice, then in effect this can be taken as implying that the recipient is capable of receiving EMS or SMS messages at this address. Such choices on the end system de do have two small Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 16] Internet-Draft Update legacy Enumservice Registrations Feb 2009 caveats; whilst in practice all terminals supporting MMS today support SMS as well, it might not necessarily be the case in the future, and there may be tariff differences in using the MMS rather than using the SMS or EMS. Application-Based, Common pres pres See , Section 4. See , Section 6. COMMON (updated by RFCTHIS) See , Section 3. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 17] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Subset (??) pstn sip sip These Enumservices indicate that the resource identified can be addressed by the associated URI in order to initiate a telecommunication session, which may include two-way voice or other communications, to the PSTN. See , Section 7. COMMON (updated by RFCTHIS) A Number Portability Dip Indicator (npdi) should be used in practice (see , Section 4). Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 18] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Ancillary pstn tel tel These Enumservices indicate that the resource identified can be addressed by the associated URI in order to initiate a telecommunication session, which may include two-way voice or other communications, to the PSTN. These URIs may contain number portability data as specified in RFC4694 [10]. See , Section 7. COMMON (updated by RFCTHIS) A Number Portability Dip Indicator (npdi) should be used in practice (see , Section 4). Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 19] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Protocol-Based sip sip, sips See , Section 4. See , Section 6. COMMON (updated by RFCTHIS) See , Section 3. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 20] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common sms mailto mailto This Enumservice indicates that the resource identified by the associated URI is capable of receiving a message using an email protocol. SMS content is sent over SMTP using the format specified by TS 23.140 [15] Section 8.4.4 and TS 26.140 [16] Section 4, as an MMS message. Within such a message, SMS content is carried as either a text or application/octet-stream MIME sub-part (see TS 26.140 [16], Section 4.1) For references see There are no specific security issues with this Enumservice. However, the general considerations of Section 6 of apply. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 21] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common sms tel tel This Enumservice indicates that the resource identified by the associated URI is capable of receiving a message using the Short Message Service (SMS) [14] in . There are no specific security issues with this Enumservice. However, the general considerations of Section 6 of apply. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 22] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Data Type-Based vcard http, https This Enumservice indicates that the resource identified is a plain vCard, according to RFC2426, which may be accessed using HTTP / HTTPS [7]. Clients fetching the vCard from the resource indicated should expect access to be restricted. Additionally, the comprehension of the data provided may vary depending on the client's identity. See , Section 5. COMMON (updated by RFCTHIS) Application-Based, Common voice tel tel The kind of communication indicated by this Enumservice is "Interactive Voice". From a protocol perspective, this communication is expected to involve bidirectional media streams carrying audio data. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 23] Internet-Draft Update legacy Enumservice Registrations Feb 2009 A client may imply that the person controlling population of a NAPTR holding this Enumservice indicates their capability to engage in an interactive voice session when contacted using the URI generated by this NAPTR. See , Section 5. COMMON (updated by RFCTHIS) This Enumservice indicates that the person responsible for the NAPTR is accessible via the PSTN (Public Switched Telephone Network) or PLMN (Public Land Mobile Network) using the value of the generated URI. The kind of subsystem required to initiate a Voice Enumservice with this Subtype is a "Dialler". This is a subsystem that either provides a local connection to the PSTN or PLMN, or that provides an indirect connection to those networks. The subsystem will use the telephone number held in the generated URI to place a voice call. The voice call is placed to a network that uses E.164 numbers to route calls to an appropriate destination. Note that the PSTN/PLMN connection may be indirect. The end user receiving this NAPTR may have a relationship with a Communications Service Provider that accepts call initiation requests from that subsystem using an IP-based protocol such as SIP or H.323, and places the call to the PSTN using a remote gateway service. In this case the Provider may either accept requests using "tel:" URIs or has Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 24] Internet-Draft Update legacy Enumservice Registrations Feb 2009 a defined mechanism to convert "tel:" URI values into a "protocol-native" form. The "tel:" URI value SHOULD be fully qualified (using the "global phone number" form of RFC3966 [10]). A "local phone number" as defined in that document SHOULD NOT be used unless the controller of the zone in which the NAPTR appears is sure that it can be distinguished unambiguously by all clients that can access the resource record and that a call from their network access points can be routed to that destination. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 25] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common (??) vpim ldap ldap See , Section 3.2 - 3.3. Malicious Redirection: One of the fundamental dangers related to any service such as this is that a malicious entry in a resolver's database will cause clients to resolve the E.164 into the wrong LDAP URI. The possible intent may be to cause the client to connect to a rogue LDAP server and retrieve (or fail to retrieve) a resource containing fraudulent or damaging information. Denial of Service: By removing the URI to which the E.164 maps, a malicious intruder may remove the client's ability to access the LDAP directory server. COMMON (updated by RFCTHIS) Application-Based, Common vpim mailto mailto See , Section 4.2 - 4.4. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 26] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Malicious Redirection: One of the fundamental dangers related to any service such as this is that a malicious entry in a resolver's database will cause clients to resolve the E.164 into the wrong email URI. The possible intent may be to cause the client to send the information to an incorrect destination. Denial of Service: By removing the URI to which the E.164 maps, a malicious intruder may remove the client's ability to access the resource. Unsolicited Bulk Email: The exposure of email addresses through the ENUM service provides a bulk mailer access to large numbers of email addresses where only the telephone number was previously known. COMMON (updated by RFCTHIS) Error Conditions: E.164 number not in the numbering plan E.164 number in the numbering plan, but no URIs exist for that number E2U+vpim:mailto Service unavailable of email addresses where only the telephone number was previously known. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 27] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common web http http This Enumservice indicates that the resource identified by the associated URI is capable of being a source of information. It has to be noted that the kind of information retrieved can be manifold. Usually, contacting a resource by an "http:" URI provides a document. This document can contain references that will trigger download of many different kinds of information, like audio or video or executable code. Thus, one can not be more specific about the kind of information that can be expected when contacting the resource. See , Section 5. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 28] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Application-Based, Common web https https This Enumservice indicates that the resource identified by the associated URI is capable of being a source of information, which can be contacted by using TLS or Secure Socket Layer protocol. It has to be noted that the kind of information retrieved can be manifold. Usually, contacting a resource by an "https:" URI provides a document. This document can contain all different kind of information, like audio or video or executable code. Thus, one can not be more specific what information to expect when contacting the resource. See , Section 5. COMMON (updated by RFCTHIS) Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 29] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Protocol-Based xmpp xmpp This Enumservice indicates that the resource identified is an XMPP entity. See , Section 6. COMMON (updated by RFCTHIS) 5. Security Considerations Since this document does not introduce any technology or protocol, there are no security issues to be considered for this document itself. 6. Acknowledgements The authors would like to thank Alfred Hoenes for his prompt feedback to this document. 7. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3761] Faltstrom, P. and M. Mealling, "The E.164 to Uniform Resource Identifiers (URI) Dynamic Delegation Discovery System (DDDS) Application (ENUM)", RFC 3761, April 2004. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 30] Internet-Draft Update legacy Enumservice Registrations Feb 2009 [I-D.ietf-enum-enumservices-guide] Bernie, H., Mayrhofer, A., and J. Livingood, "IANA Registration of Enumservices: Guide, Template and IANA Considerations", draft-ietf-enum-enumservices-guide-15 (work in progress), December 2008. [RFC3762] Levin, O., "Telephone Number Mapping (ENUM) Service Registration for H.323", RFC 3762, April 2004. [RFC3764] Peterson, J., "enumservice registration for Session Initiation Protocol (SIP) Addresses-of-Record", RFC 3764, April 2004. [RFC3953] Peterson, J., "Telephone Number Mapping (ENUM) Service Registration for Presence Services", RFC 3953, January 2005. [RFC4143] Toyoda, K. and D. Crocker, "Facsimile Using Internet Mail (IFAX) Service of ENUM", RFC 4143, November 2005. [RFC4002] Brandner, R., Conroy, L., and R. Stastny, "IANA Registration for Enumservice 'web' and 'ft'", RFC 4002, February 2005. [RFC4238] Vaudreuil, G., "Voice Message Routing Service", RFC 4238, October 2005. [RFC4355] Brandner, R., Conroy, L., and R. Stastny, "IANA Registration for Enumservices email, fax, mms, ems, and sms", RFC 4355, January 2006. [RFC4415] Brandner, R., Conroy, L., and R. Stastny, "IANA Registration for Enumservice Voice", RFC 4415, February 2006. [RFC4769] Livingood, J. and R. Shockey, "IANA Registration for an Enumservice Containing Public Switched Telephone Network (PSTN) Signaling Information", RFC 4769, November 2006. [RFC4969] Mayrhofer, A., "IANA Registration for vCard Enumservice", RFC 4969, August 2007. [RFC4979] Mayrhofer, A., "IANA Registration for Enumservice 'XMPP'", RFC 4979, August 2007. [RFC5028] Mahy, R., "A Telephone Number Mapping (ENUM) Service Registration for Instant Messaging (IM) Services", RFC 5028, October 2007. Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 31] Internet-Draft Update legacy Enumservice Registrations Feb 2009 [I-D.ietf-enum-calendar-service] Mahy, R., "A Telephone Number Mapping (ENUM) Service Registration for Internet Calendaring Services", draft-ietf-enum-calendar-service-04 (work in progress), March 2008. Appendix A. Former Content of the IANA Repository Todo: Copy-Paste from existing IANA Repository Appendix B. Document Changelog [RFC Editor: This section is to be removed before publication] draft-ietf-enum-enumservices-transition-00: o bernie: Updated affliation: Switch -> Swisscom o bernie: Revised all Enumservices to the form of XML chunks o bernie: Added statement for IESG Actions to downgrade existing all Enumservice specifications o bernie: Updated 'Open Issues' section draft-hoeneisen-enum-enumservices-transition-01: o bernie: Fixed wrong reference draft-hoeneisen-enum-enumservices-transition-01: o bernie: integrated feedback from Alfred Hoenes * Typos / corrections * Removed the words "remote" and "scheme" in existing registrations * changed "URL" to "URI" in existing registrations * changed "headers" to "header fields" in existing "mms:mailto" registration o bernie: Added Acknowledgements section draft-hoeneisen-enum-enumservices-transition-00: o bernie: Initial version o bernie: Imported and adjusted existing IANA Enumservice registrations o bernie: Removed Name and added Class fields o bernie: Put caption to each Enumservice o bernie: Sorted alphabetically o bernie: All URI Schemes without colon o alex: Added classification Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 32] Internet-Draft Update legacy Enumservice Registrations Feb 2009 Appendix C. Open Issues [RFC Editor: This section should be empty and is to be removed before publication] o Improve language in Section 'IESG Actions' o Check for completeness compared to http://www.iana.org/assignments/enum-services o Finalize classitfaction, where unsure o Authors of Enumservices to review the changes o Maybe change presentation of prose parts (quotes, colons) Authors' Addresses Bernie Hoeneisen Swisscom Hardturmstrasse 3 CH-8005 Zuerich Switzerland Phone: +41 44 2747111 Email: bernie@ietf.hoeneisen.ch (bernhard.hoeneisen AT swisscom.com) URI: http://www.swisscom.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/ Hoeneisen & Mayrhofer Expires August 19, 2009 [Page 33]