10 IP multimedia application support in the IM CN subsystem using webRTC

24.3713GPPProtocol specificationRelease 17Stage 3TSWeb Real-Time Communications (WebRTC) access to the IP Multimedia (IM) Core Network (CN) subsystem (IMS)

10.1 General

10.2 Access to MMTel and supplementary services using webRTC

10.2.1 General

This clause describes the procedures for interaction of WebRTC based access to the IM CN subsystem and the execution of supplementary service as described in 3GPP TS 22.173 [7].

10.2.2 WIC (WebRTC IMS Client)

10.2.2.1 SIP based protocol used by the WIC

If the protocol between the WIC and the eP-CSCF is based on SIP, then in order to support an MMTel supplementary service, the SIP procedures shall conform to the SIP procedures specified in the 24 series specification of the respective supplementary service. 3GPP TS 24.173 [8] lists the documents defining the MMTel supplementary services.

10.2.2.2 non-SIP based protocol used by the WIC

The support of MMTel supplementary services when accessing the IM CN subsystem with non-SIP based protocol is not specified in this version of the specification.

10.2.3 WWSF (WebRTC Web Server Function)

10.2.4 eP-CSCF (P-CSCF enhanced for WebRTC)

When a SIP is used on the W2 interface, then there are no supplementary specific requirements defined for the eP-CSCF.

When a non-SIP protocol is used on the W2 interface, then the eP-CSCF has to map information elements from non-SIP based protocol on W2 interface to the corresponding SIP information elements on the Mw reference point.

Annex A (informative):
Example signalling flows