IANA Registration for Enumservices email, fax, mms, ems, and sms
updated by
- rfc-6118 — Update of Legacy IANA Registrations of Enumservices
Extracted elements (14)
Enumservice registrations use a 'type' (the service) and 'subtype' (the URI scheme) convention because the same URI scheme may serve different services and the same service may use multiple URI schemes; the subtype is needed even when only one URI scheme is currently associated with a service, as additional schemes may be added later.
The SMS, EMS, and MMS capability is a nested superset: a resource advertising MMS support can also receive EMS and SMS content, and a resource advertising EMS support can also receive SMS content. Clients MAY therefore consider NAPTRs for higher-capability services when sending lower-capability content.
MMS over the 'mailto:' URI scheme uses the MM3 interface, where the MMS Relay Server appears as a standard SMTP server to Internet mail servers but acts as a gateway adding internal MMSE state data as specialised headers, as specified in RFC 4356.
Data subjects MUST give their explicit informed consent before their data is published in ENUM, due to the implications of publishing personal contact information on a globally accessible DNS-based database.
End-users SHOULD be shown the destination number when sending fax or charged messages (e.g., via sms:tel, ems:tel, mms:tel Enumservices) so that they can confirm or cancel before sending, particularly for premium-rate numbers.
Each Enumservice registration in this document specifies a type, one or more subtypes, a URI scheme, and a functional specification, following the DDDS 'E2U' application for ENUM NAPTR records as defined in RFC 3761.
Registers the 'email' Enumservice with type 'email', subtype 'mailto', using the 'mailto:' URI scheme to indicate that the remote resource can be addressed to send an email.
Registers the 'ems' Enumservice with type 'ems', subtype 'mailto', using the 'mailto:' URI scheme; EMS content is sent over SMTP as an MMS message per 3GPP TS 23.140 Section 8.4.4 and TS 26.140.
Registers the 'fax' Enumservice with type 'fax', subtype 'tel', using the 'tel:' URI scheme to indicate capability of receiving facsimile documents over PSTN using ITU-T T.4 and T.30 protocols.
Registers the 'mms' Enumservice with type 'mms', subtype 'mailto', using the 'mailto:' URI scheme; MMS messages are sent over SMTP per 3GPP TS 23.140 Section 8.4.4, with MMS Relay Servers mapping internal state to specialised SMTP headers.
Registers the 'sms' Enumservice with type 'sms', subtype 'mailto', using the 'mailto:' URI scheme; SMS content is sent over SMTP as an MMS message per 3GPP TS 23.140 Section 8.4.4, carried as text or application/octet-stream MIME sub-part.
Email addresses placed in ENUM are publicly available to all DNS inquirers. Subscribers should be made aware that ENUM records are open to the public, and that email addresses may allow inference of private data such as first and last name.
ENUM data stored in DNS is globally visible and anonymous. Publishing telephone numbers and email addresses in ENUM exposes data subjects to automated harvesting for spam, junk faxes, and unsolicited SMS; unlike email, users cannot easily use 'sacrificial' phone numbers.
Sending an SMS, EMS, or MMS to certain special service numbers may trigger a subscription contract with premium charges. It is critical that end terminals present the destination tel: URI before sending via sms:tel, ems:tel, or mms:tel Enumservices to let users cancel.