With IP, it's usually a software defined network model, along with some IGMP components for controlling video flow.
So the clients (software or control panels) would send a request to the routing orchestration system to request a route to send multicast flows (SMPTE 2110, separate multicast for video, audio streams, ancillary data) from a source to a destination, same as with a baseband router. With IP, the orchestration layer also drives the receiving device to join the multicast explicitly if it isn't IGMP based.
This is our SDN orchestration; https://evertz.com/solutions/magnum
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