11.2 Requirements

22.2283GPPRelease 16Service requirements for the Internet Protocol (IP) multimedia core network subsystem (IMS)Stage 1TS

When accessing IMS services via WebRTC IMS client the IMS shall allow a user to access IMS services from an application offered either directly by the IMS operator or by a third party.

The IMS shall be able to support access to the following IMS services and capabilities for WebRTC IMS client access:

– multimedia telephony[20], excluding fax and CS data,

– early media, and

– network tones and announcements.

Note: IMS Multimedia Emergency Sessions [5] are not supported for WebRTC IMS Client access.

The IMS shall support online and offline charging for WebRTC IMS client access (including clients provided by the operator or a third party).

The available services and capabilities for WebRTC IMS clients accessing IMS shall be determined according to operator policy and user subscription settings in IMS.

Note: The available services and capabilities can be further limited by the provider of the WebRTC IMS client (e.g. operator or a third party), by the capabilities of the WebRTC IMS client (e.g. no video support), and/or by the IP access used to access the IMS network (e.g. IP access networks without QoS support).

The IMS shall support service origination and service termination with a WebRTC IMS Client. The IMS shall support media and protocol interworking and/or transcoding, when necessary.

3GPP system shall provide the appropriate QoS (based on operator policy and user subscription) for WebRTC IMS client traffic originating from an access network supporting QoS.

When accessing IMS services via a WebRTC IMS client, the IMS shall provide the equivalent levels of security and integrity as it provides when accessing IMS services in other ways.

The 3GPP UE shall make available for use by the WebRTC IMS client the codecs whose support is mandatory for the access technology being used to access IMS services.

The IMS shall authenticate the user that accesses IMS services using credentials provided by the operator or credentials provided by authorized third party (for web-identity based authentication) via a WebRTC IMS client and associate the user to one or more public identities (e.g. IMS Public User Identity or MSISDN).

Note: The authentication of the subscriber can be performed via the WebRTC IMS client or by a WebRTC server on behalf of a user.

When supporting WebRTC IMS client access, the IMS shall maintain compliance with regulatory requirements for IMS services.

When accessing IMS services via WebRTC IMS client, the IMS shall allow a subscriber to access call management.

For WebRTC IMS client to WebRTC IMS client communication, the IMS shall support traversal of media across NAT devices.