10 Media control

24.2293GPPIP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Release 18Stage 3TS

10.1 General

The choice of which media control methods below to use is service specific, it depends on the functionality required and physical deployment architectures.

Combinations of the capabilities below are supported by the use of the control channel framework RFC 6230 [146] with associated media control packages.

For security, the principles and protocols described in 3GPP TS 33.210 [19A] shall take precedence over those specified in the referenced specifications in this clause.

For codecs, those described in access specific specifications shall take precedence over those specified in the referenced specifications in this clause.

10.2 Procedures at the AS

10.2.1 General

An AS requesting charging information and authorisation for specific media operations and media usage controlled by the MRFC shall use RFC 6230 [146] together with appropriate packages.

NOTE: This is in addition to the charging related procedures in clause 5 and to the charging information and authorisation requests, defined in 3GPP TS 32.260 [17] which provide charging information and authorisation for SIP session and SDP information.

An AS may support delegation of an XML (such as CCXML or SCXML) script execution to an MRFC. An AS supporting delegation of XML script execution shall use RFC 6230 [146] together with appropriate packages.

The packages, or extensions to existing packages using RFC 6230 [146] framework are not specified in this release.

The AS may support the media server resource consumer interface as defined by RFC 6917 [192]. If supported the AS can support either the in-line mode or the query mode or both.

10.2.2 Tones and announcements

10.2.2.1 General

An AS may support control of the MRFC for tones and announcements. An AS supporting control of the MRFC for tones and announcements shall support one or more of the following methods:

– RFC 4240 [144] announcement service;

– RFC 5552 [145]; or

– RFC 6230 [146] and RFC 6231 [147].

10.2.2.2 Basic network media services with SIP

The AS may support control of the MRFC for basic announcements by the use of RFC 4240 [144] and the announcement service described in RFC 4240 [144] subclause 3.

The media control commands are carried between the AS and the MRFC either directly over the Mr’ interface or via the S-CSCF over the ISC and Mr interfaces.

The AS shall provide remote prompts to the MRFC using the AS-MRFC Cr interface.

10.2.2.3 SIP interface to VoiceXML media services

The AS may support control of the MRFC for voice dialogs by the use of RFC 5552 [145].

The media control commands are carried between the AS and the MRFC either directly over the Mr’ interface or via the S-CSCF over the ISC and Mr interfaces.

The AS shall provide remote prompts and scripts to the MRFC using the AS-MRFC Cr interface.

Data shall be returned to the AS from the MRFC by either use of the AS-MRFC Cr interface (subclause 4.1 of RFC 5552 [145]), via the ISC interface (subclause 4.2 of RFC 5552 [145]) or via the Mr’ interface.

10.2.2.4 Media control channel framework and packages

The AS may support control of the MRFC for interactive voice response by the use of RFC 6231 [147] and RFC 6230 [146].

The AS shall provide remote prompts, media control commands and scripts to the MRFC using the AS-MRFC Cr interface.

The AS shall implement the control client role as described in RFC 6230 [146].

10.2.3 Ad-hoc conferences

10.2.3.1 General

An AS may support control of the MRFC for ad-hoc conferencing. An AS supporting control of the MRFC for ad-hoc conferencing shall support one or more of the following methods:

– RFC 4240 [144] conference service; or

– RFC 6230 [146] and RFC 6505 [148].

10.2.3.2 Basic network media services with SIP

The AS may support control of the MRFC for basic conferencing by the use of RFC 4240 [144] and the conference service described in RFC 4240 [144] subclause 5.

The media control commands are carried between the AS and the MRFC either directly over the Mr’ interface or via the S-CSCF over the ISC and Mr interfaces.

10.2.3.3 Media control channel framework and packages

The AS may support control of the MRFC for conference mixing by the use of RFC 6505 [148] and RFC 6230 [146].

An AS may support control of the MRFC for floor controlled conferences (as specified in 3GPP TS 24.147 [8B]), via the use of RFC 6230 [146] together with appropriate packages. The packages, or extensions to existing packages using RFC 6230 [146] framework are not specified in this release.

An AS may support control of the MRFC for session-mode messaging conferences (as specified in 3GPP TS 24.247 [8F]), via the use of RFC 6230 [146] together with appropriate packages. The packages, or extensions to existing packages using RFC 6230 [146] framework are not specified in this release.

The AS shall provide media control commands to the MRFC using the AS-MRFC Cr interface.

The AS shall implement the control client role as described in RFC 6230 [146].

10.2.4 Transcoding

10.2.4.1 General

An AS may support control of the MRFC for transcoding. An AS supporting control of the MRFC for transcoding shall support one or more of the following methods:

– RFC 4240 [144] conference service; or

– RFC 6230 [146] and RFC 6505 [148].

10.2.4.2 Basic network media services with SIP

The AS may support control of the MRFC for transcoding by the use of RFC 4240 [144] and the conference service described in RFC 4240 [144] subclause 5.

The media control commands are carried between the AS and the MRFC either directly over the Mr’ interface or via the S-CSCF over the ISC and Mr interfaces.

10.2.4.3 Media control channel framework and packages

The AS may support control of the MRFC for transcoding by the use of RFC 6505 [148] and RFC 6230 [146].

The AS shall provide media control commands to the MRFC using the AS-MRFC Cr interface.

The AS shall implement the control client role as described in RFC 6230 [146].

10.3 Procedures at the MRFC

10.3.1 General

An MRFC required to generate charging information and authorize requests from an AS for specific media operations and media usage shall support RFC 6230 [146] together with appropriate packages.

NOTE: This is in addition to the charging related procedures in clause 5 and to the charging information and authorisation requests, defined in 3GPP TS 32.260 [17] which provide charging information and authorisation for SIP session and SDP information.

An MRFC may support delegated XML (such as CCXML or SCXML) script execution from an AS. An MRFC supporting delegation of XML script execution shall use RFC 6230 [146] together with appropriate packages.

The packages, or extensions to existing packages using RFC 6230 [146] framework above are not specified in this release.

The MRFC may support the media server resource publish interface as defined by RFC 6917 [192].

10.3.2 Tones and announcements

10.3.2.1 General

An MRFC may support control of tones and announcements. An MRFC supporting control of tones and announcements shall support one or more of the following methods:

– RFC 4240 [144] announcement service;

– RFC 5552 [145]; or

– RFC 6230 [146] and RFC 6231 [147].

10.3.2.2 Basic network media services with SIP

The MRFC may support control of basic announcements by the use of RFC 4240 [144] and the announcement service described in RFC 4240 [144] subclause 3.

The media control commands are received from the AS either directly over the Mr’ interface or via the S-CSCF over the ISC and Mr interfaces.

The MRFC shall fetch remote prompts from the AS using the AS-MRFC Cr interface.

The MRFC acts as the media server described in RFC 4240 [144].

10.3.2.3 SIP interface to VoiceXML media services

The MRFC may support control of voice dialogs by the use of RFC 5552 [145].

The media control commands are received from the AS either directly over the Mr’ interface or via the S-CSCF over the ISC and Mr interfaces.

The MRFC shall fetch via the AS-MRFC Cr interface the remote prompts and scripts from the address included in the "voicexml" URI parameter, if received, in the Request-URI of the SIP INVITE request.

Data shall be returned to the AS from the MRFC by either use of the AS-MRFC Cr interface (subclause 4.1 of RFC 5552 [145]), via the ISC interface (subclause 4.2 of RFC 5552 [145]) or via the Mr’ interface.

The MRFC acts as the VoiceXML media server described in RFC 5552 [145].

10.3.2.4 Media control channel framework and packages

The MRFC may support control of interactive voice response by the use of RFC 6231 [147] and RFC 6230 [146].

The MRFC shall fetch remote prompts and scripts from the MRFC using the AS-MRFC Cr interface. The MRFC shall send media control command responses and notifications to the AS using the AS-MRFC Cr interface.

The MRFC shall implement the control server role as described in RFC 6230 [146].

10.3.3 Ad-hoc conferences

10.3.3.1 General

An MRFC may support control of ad-hoc conferencing. An MRFC supporting control of ad-hoc conferencing shall support one or more of the following methods:

– RFC 4240 [144] conference service; or

– RFC 6230 [146] and RFC 6505 [148].

10.3.3.2 Basic network media services with SIP

The MRFC may support control of basic conferencing by the use of RFC 4240 [144] and the conference service described in RFC 4240 [144] subclause 5.

The media control commands are received from the AS either directly over the Mr’ interface or via the S-CSCF over the ISC and Mr interfaces.

The MRFC acts as the media server described in RFC 4240 [144].

10.3.3.3 Media control channel framework and packages

The MRFC may support control of conference mixing by the use of RFC 6505 [148] and RFC 6230 [146].

An MRFC may support control of floor controlled conferences (as specified in 3GPP TS 24.147 [8B]), via the use of RFC 6230 [146] together with appropriate packages. The packages, or extensions to existing packages using RFC 6230 [146] framework are not specified in this release. In addition, the MRFC may support the procedures for a multi-stream multiparty multimedia conference using simulcast defined in 3GPP TS 26.114 [9B] annex S.

An MRFC may support control of session-mode messaging conferences (as specified in 3GPP TS 24.247 [8F]), via the use of RFC 6230 [146] together with appropriate packages. The packages, or extensions to existing packages using RFC 6230 [146] framework are not specified in this release.

The MRFC shall send media control command responses and notifications to the AS using the AS-MRFC Cr interface.

The MRFC shall implement the control server role as described in RFC 6230 [146].

10.3.4 Transcoding

10.3.4.1 General

An MRFC may support control of transcoding. An MRFC supporting control of transcoding shall support one or more of the following methods:

– RFC 4240 [144] conference service;

– RFC 6230 [146] and RFC 6505 [148]; or

– RFC 4117 [166]. This is detailed in subclause 5.7.5.6.

10.3.4.2 Basic network media services with SIP

The MRFC may support control of transcoding by the use of RFC 4240 [144] and the conference service described in RFC 4240 [144] subclause 5.

The media control commands are received from the AS either directly over the Mr’ interface or via the S-CSCF over the ISC and Mr interfaces.

The MRFC acts as the media server described in RFC 4240 [144].

10.3.4.3 Media control channel framework and packages

The MRFC may support control of transcoding by the use of RFC 6505 [148] and RFC 6230 [146].

The MRFC shall send media control command responses and notifications to the AS using the AS-MRFC Cr interface.

The MRFC shall implement the control server role as described in RFC 6230 [146].

10.4 Procedures at the MRB

The MRB shall support:

a) the in-line unaware MRB interface.

as defined in RFC 5917 [192].

The MRB may support:

a) the media server resource publish interface; and

b) the media server resource consumer interface;

as defined in RFC 6917 [192].

Annex A (normative):
Profiles of IETF RFCs for 3GPP usage