Which SIP Trunk setting is needed to enable BFCP?

Redirecting Diversion Header Delivery - Outbound controls how diversion headers are passed for redirected calls and has no relationship to BFCP content sharing negotiation.

Rerouting CSS (Calling Search Space) defines call routing and class of service permissions and does not control SIP protocol-level features like BFCP.

The SIP Profile in CUCM controls detailed SIP behavior for trunks and devices, including whether BFCP is advertised in SDP offers for content sharing. To enable BFCP on a SIP Trunk, a custom SIP Profile must be created with the BFCP option enabled and then applied to the trunk configuration. This profile-based approach lets administrators selectively enable advanced SIP features per trunk or device without affecting the entire system.

SIP Trunk Security Profile governs transport security, authentication, and encryption settings for the trunk, not the SIP feature set or BFCP capability negotiation.