diff --git a/xep-0181.xml b/xep-0181.xml index 2f19b581..a23394d6 100644 --- a/xep-0181.xml +++ b/xep-0181.xml @@ -7,7 +7,7 @@
Jingle DTMF - This specification defines an XML format for encapsulating Dual Tone Multi-Frequency (DTMF) data in informational messages sent within the context of Jingle audio sessions, e.g. to be used in the context of Interactive Voice Response (IVR) systems. + This specification defines an XML format for encapsulating Dual Tone Multi-Frequency (DTMF) events in informational messages sent within the context of Jingle audio sessions, e.g. to be used in the context of Interactive Voice Response (IVR) systems. &LEGALNOTICE; 0181 Proposed @@ -20,9 +20,21 @@ - TO BE ASSIGNED + TO-BE-ASSIGNED &stpeter; &seanegan; + + 0.9 + 2008-04-18 + psa +

Removed negotiation flow so that this specification describes only the XMPP transport of DTMF events; added error flows to be used if the code is not understood or if a non-XMPP method is preferred.

 + + + 0.8 + 2008-03-20 + psa +

Clarified negotiation flow; added payload-types per RFC 4733.

 + 0.7 2007-11-27 @@ -73,18 +85,22 @@
-

Traditional telephony systems use Dual Tone Multi-Frequency (DTMF) for dialing and to issue commands such as those used in Interactive Voice Response (IVR) applications. Internet telephony systems also use DTMF tones for interoperability with the public switched telephone network (PSTN).

-

XMPP clients that use &xep0166; for voice chat (see &xep0167;) MUST support the protocol described in this document to exchange DTMF information, although they MAY also support other methods of communicating DTMF information.

+

Traditional telephony systems use Dual Tone Multi-Frequency (DTMF) events for dialing and to issue commands such as those used in Interactive Voice Response (IVR) applications. Internet telephony systems also use DTMF tones for interoperability with the public switched telephone network (PSTN).

+

If XMPP application use &xep0166; for voice chat (see &xep0167;) and wish to exchange DTMF events, they MUST support the protocol described in this document. However, they MAY also support non-XMPP methods of communicating DTMF information, such as the "audio/telephone-event" and "audio/tone" media types as sent over the Real-time Transport Protocol (&rfc3550;).

 - -

The format for the XML DTMF representation is as follows &NSNOTE;:

+ +

The format for the representation of DTMF events in XMPP is as follows &NSNOTE;:

+ code='0-9,#,*,A-D' + duration='milliseconds' + volume='0-63'/> ]]> -

The <dtmf/> element SHOULD possess an 'action' attribute, the value of which MUST be either "button-up" or "button-down" (specifying whether the button is being depressed or released). This enables DTMF tones to be reconstructed in real time. If the 'action' attribute is not included, the recipient MUST assume that the action is a "button-down" event and act as if a "button-up" event occurs after a reasonable timeout (100 milliseconds is RECOMMENDED) or when another DMTF event is received.

-

Unless the 'action' attribute has a value of "button-up", the <dmtf/> element MUST possess a 'code' attribute that specifies the tone to be generated. The value of the 'code' attribute SHOULD be one the following characters: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, #, and * -- however, the characters A, B, C, and D MAY be sent as well. Although A, B, C, and D were originally defined as part of DTMF, they were never deployed to telephony consumers and were used only for control purposes at private branch exchanges (PBXs) and central office operator stations; however, they are used in certain non-telephony applications of DTMF, such as ham radio.

+

The <dtmf/> element SHOULD possess an 'action' attribute, the value of which MUST be either "button-up" or "button-down" (specifying whether the button is being depressed or released). This enables DTMF tones to be reconstructed in real time. If the 'action' attribute is not included, the recipient MUST assume that the action is a "button-down" event.

+

Unless the 'action' attribute has a value of "button-up", the <dmtf/> element MUST possess a 'code' attribute that specifies the tone to be generated. The value of the 'code' attribute SHOULD be one the following characters: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, #, and * (however, the characters A, B, C, and D MAY be sent as well Although A, B, C, and D were originally defined as part of DTMF, they were never deployed to telephony consumers and were used only for control purposes at private branch exchanges (PBXs) and central office operator stations; however, they are used in certain non-telephony applications of DTMF, such as ham radio.).

+

The OPTIONAL 'duration' attribute specifies indicates the duration of the event, in milliseconds, expressed as an unsigned integer. The receiver SHOULD ignore the event if the 'duration' value is zero. If the 'duration' attribute is not included and the event is explicitly or implicitly a "button-down" event, the recipient MUST assume that the event expires after a reasonable timeout (100 milliseconds is RECOMMENDED) or when a "button-up" event is received, whichever comes first.

+

The OPTIONAL 'volume' attribute specifies the power level of the tone, expressed in dBm0 after dropping the sign. Power levels range from 0 to -63 dBm0. Thus, larger values denote lower volume.

The <dtmf> element SHOULD be sent as the payload of a Jingle session-info message as illustrated in the following example &NSNOTE;.

+ code='7' + duration='400' + volume='42'/> ]]> @@ -108,61 +126,43 @@ to='juliet@capulet.com/balcony' type='result'/> ]]> -

If the receiving entity does not understand or cannot process the payload, it MUST return a &feature; stanza error, which SHOULD include a Jingle-specific error condition of <unsupported-info/>.

- If the receiving entity does not support this protocol, it MUST return a &unavailable; stanza error.

+ + + + + + ]]> +

If the receiving entity does not understand the specified code, it MUST return a &feature; stanza error.

+ - + + + ]]> +

If the receiving entity is using or wishes to use a different method for exchanging DTMF events (e.g., the methods specified in &rfc2833; or its successor &rfc4733;), it MUST return a ¬acceptable; stanza error.

+ + + ]]> - -

Some applications may want to stream Jingle voice RTP directly to a non-XMPP entity, such as a SIP phone (see &rfc3261;). In this scenario, DTMF needs to be sent in the content channel. Jingle DTMF enables Jingle entities to negotiate whether to send RTP over the XMPP signalling channel as described above, or over the content channel using &rfc4733;.

-

To request that the voice session will switch to use of the RFC 4733 format for communicating DTMF, a client sends a <dtmf-method/> element, qualified by the 'urn:xmpp:tmp:jingle:dtmf' namespace as the payload of a Jingle session-info message:

- - - - - - ]]> -

The dtmf-method element MUST contain one 'method' attribute, the value of which SHOULD be either 'rtp' or 'xmpp'.

-

If the recipient supports the requested DTMF method and wishes to use that method, it MUST send an empty IQ result:

- - ]]> -

If the recipient does not support the requested DTMF method, it MUST return a <feature-not-implemented/> stanza error, which SHOULD include a DTMF-specific error condition of <unsupported-dtmf-method/>:

- - - - - - - ]]> - -

If an entity supports Jingle DTMF (which natively includes sending of DTMF in the XMPP signalling channel), it MUST return a &xep0030; feature of "urn:xmpp:tmp:jingle:dtmf" in response to service discovery information requests.

-

If an entity also supports sending of DTMF in the content channel, it MUST also return a service discovery feature of "urn:xmpp:jingle:dtmf:rtp" in response to service discovery information requests.

-

Naturally, support MAY also be determined via the dynamic, presence-based profile of Service Discovery defined in &xep0115;.

+

If an entity supports Jingle DTMF (i.e., sending of DTMF in the XMPP signalling channel as specified herein), it MUST return a &xep0030; feature of "urn:xmpp:tmp:jingle:dtmf" in response to service discovery information requests. Naturally, support MAY also be determined via the dynamic, presence-based profile of Service Discovery defined in &xep0115;.

 @@ -175,26 +175,12 @@ -

Until this specification advances to a status of Draft, its associated namespaces shall be:

-
    -
  • urn:xmpp:tmp:jingle:dtmf
    • -
  • urn:xmpp:tmp:jingle:dtmf:errors
    • -
-

Upon advancement of this specification, the ®ISTRAR; shall issue permanent namespaces in accordance with the process defined in Section 4 of &xep0053;.

-

The following namespaces are requested, and are thought to be unique per the XMPP Registrar's requirements:

-
    -
  • urn:xmpp:jingle:dtmf
    • -
  • urn:xmpp:jingle:dtmf:errors
    • -
- - -

The XMPP Registrar shall include "urn:xmpp:jingle:dtmf:rtp" in its registry of service discovery features (see &DISCOFEATURES;).

+

Until this specification advances to a status of Draft, its associated namespace shall be "urn:xmpp:tmp:jingle:dtmf". Upon advancement of this specification, the ®ISTRAR; shall issue a permanent namespace in accordance with the process defined in Section 4 of &xep0053;. The following namespace is requested, and is thought to be unique per the XMPP Registrar's requirements: "urn:xmpp:jingle:dtmf".

 - - - - - - - - - - - - - - - - - - - + + @@ -244,27 +215,13 @@ - - - + + + + - - ]]> - - - - - - - - @@ -272,7 +229,9 @@ - ]]> - + ]]> + + +

Thanks to Olivier Crête and Paul Witty for their feedback. Several sentences were borrowed from RFC 4733.