IANA Registration for IAX Enumservice

The E.164 to Uniform Resource Identifiers (URI) Dynamic Delegation Discovery System (DDDS) Application (ENUM) transforms E.164 numbers into DNS names. Then, using DNS services like delegation through NS records and NAPTR records, one can look up what services are available for a specific domain name. IAX (Inter-Asterisk eXchange) is an "all in one" protocol for handling multimedia in IP networks. It combines both control and media services in the same protocol. In addition, IAX uses a single UDP data stream on a static port greatly simplifying Network Address Translation (NAT) gateway traversal, eliminating the need for other protocols to work around NAT, and simplifying network and firewall management. IAX employs a compact encoding which decreases bandwidth usage and is well suited for Internet telephony service. In addition, its open nature permits new payload types additions needed to support additional services. This document registers the IAX Enumservice according to the guidelines given in RFC3761 . The IAX Enumservice is used in provisioning the services field of a NAPTR resource record. This field indicates what class of functionality a given end point offers.

Enumservice Name: "IAX" Enumservice Type: "iax" URI Scheme: "iax" Functional Specification: The IAX Enumservice indicates that the resource identified by the associated URI scheme is capable of being contacted using the IAX protocol to provide a communication session. A client selecting this NAPTR needs to be able to support call origination utilizing the IAX protocol . Security Considerations: There are no specific security issues with this Enumservice. However, the general considerations of apply. Intended Usage: COMMON Author: Ed Guy <edguy@emcsw.com> Any other information the author deems interesting: None.

The following is an example of the use of the Enumservice registered by this document in a NAPTR resource record.

This contact information indicates that service identified by the "+442079460148" E.164 number can be accessed using the IAX protocol to domain 'example.com.' The called party, service, or program on that domain is identified by 'chas'.

The next example demonstrates that service identified by the "+441632960083" E.164 number is preferably accessed by IAX, secondly via SIP , and then H.323 for voice and general commmunication, and lastly by SMTP for messaging. Note that the tokens "iax", "sip", "h323", and "email" are types registered with IANA, and they have no implicit connection with the protocols or URI schemes with the same names. In each case, the next step in the resolution process is to use the resolution mechanism appropriate to each of the protocols, (specified by the URI schemes iax, sip, and h323).

The following is an example of the use of the Enumservice registered by this document in a NAPTR resource record that contains a destination 'context'.

This contact information indicates that the domain 9.4.1.0.6.4.9.7.0.2.4.4.e164.arpa. may be contacted by using the IAX protocol at domain 'example.com' with the called party 'joe' in the context (or user partition) 'developers'. See Section Section 2 of .

The following is an example of the use of the Enumservice registered by this document in a NAPTR resource record that contains an IPV6 destination address.

This contact information indicates that the domain 9.4.1.0.6.4.9.7.0.2.4.4.e164.arpa. may be contacted by using the IAX protocol at IPv6 address [2001:db8::1], port 4569 with the called party 'alice' in the context (or user partition) 'friends'.

The IAX Enumservice does not introduce any new security issues beyond any already present in the ENUM, DNS and IAX protocols except that this Enumservice provides another fact, visible to anyone anonymously, that may be harvested and possibly exploited. The primary result of these exploits is unwanted communications. These issues are discussed in further detail in RFC 4035 and RFC 3822 . The use of DNSSEC is recommended to improve operational security.

This document requests registration of the "iax" Enumservice with the 'iax' sub-type according to the guidelines and specifications in RFC 3761 and the definitions in in this document.

This work was supported by Internet Foundation Austria. In addition, thanks to Michael Haberler and Richard Stastny for their support and guidance in writing this document.

[Note to Editor: This section is to be removed before publishing. Xml source is available upon request.]

* Removed the 'iax2' subtype per AD request. * Change from standards track to informational track. * Added citation to second paragraph.

* Removed version number '2' from scheme name. * IDNITS: removed terminology section. * Various rewordings per Alex Mayrhofer and idnits review. * Added E2U+email:mailto example to match text,

* Clarifications suggested by Peter Koch.

* Add reference to provisionally registered URI scheme. * Separate normative and informative references. * Minor grammatical edits. * Added the IPv6 Example. * Updated References.

* Minor grammatical edits. * Added the 'iax2' subtype at WG request. * The Examples section was split into subsections for each example. * Context example added.