C.4 Definition of feature-capability indicator g.3gpp.atcf

24.2373GPPIP Multimedia (IM) Core Network (CN) subsystem IP Multimedia Subsystem (IMS) service continuityRelease 17Stage 3TS

Feature-capability indicator name: g.3gpp.atcf

Summary of the feature indicated by this feature-capability indicator:

This feature-capability indicator when included in a Feature-Caps header field as specified in IETF RFC 6809 [60] in a SIP REGISTER request or a SIP response to the SIP REGISTER request indicates presence and support of a resource which is an Access Transfer Control Function (ATCF) and also the session transfer number allocated to the ATCF.

Feature-capability indicator specification reference:

3GPP TS 24.237, http://www.3gpp.org/ftp/Specs/archive/24_series/24.237/

Values appropriate for use with this feature-capability indicator:

None or string with an equality relationship. When used in a Feature-Caps header field in SIP REGISTER request or response, the value is string containing the session transfer number allocated to the ATCF following the syntax as described in table C.4-1 for g-3gpp-atcf-in-path.

Table C.4-1: ABNF syntax of values of the g.3gpp.atcf feature-capability indicator

g-3gpp-atcf-in-path = STN-SR

STN-SR = "<" addr-spec ">"

The feature-capability indicator is intended primarily for use in the following applications, protocols, services, or negotiation mechanisms: This feature-capability indicator is used to indicate support of the ATCF.

Examples of typical use: Indicating the presence and support of an ATCF on the routing path of the SIP REGISTER request and SIP response to the SIP REGISTER request and providing the session transfer number allocated to this ATCF.

Security Considerations: Security considerations for this feature-capability indicator are discussed in clause 9 of IETF RFC 6809 [60].