It depends on your system. For example, until recently nginx on Windows was limited to 1,024 connections. That meant that with WebSockets you had 512 connections between the clients and nginx and 512 connections between nginx and Lucee (that limit may have been removed as I don’t see it on their website anymore).
So if one uses nginx on Windows on a version that is limited that way one’s limit would be 512 WebSocket connections. YMMV.