Which of these devices require configuration in order for an endpoint to initiate a Multiway conference?

Configuring only the endpoint leaves the VCS without routing policy and the MCU without the settings to host the escalated conference.

Configuring only the VCS does not give the endpoint the Multiway address to initiate a request or the MCU the configuration to accept the conference.

Configuring only the MCU does not enable the endpoint to trigger a Multiway request or the VCS to route it to the MCU.

Configuring the endpoint and MCU skips the VCS, which is the required intermediary for intercepting and routing the Multiway escalation request.

Configuring the endpoint and VCS omits the MCU, which must also be set up to accept and host the escalated multipoint conference.

The endpoint must be provisioned with the Multiway conference factory address so it can initiate an escalation request; the Cisco TelePresence VCS must have Multiway policy configured to intercept the escalation and route it to an MCU; and the MCU must be configured to accept and host the resulting ad-hoc conference. A gap in any one of the three devices breaks the escalation chain entirely.