Automatic termination of schedule webcasts

When scheduling a live webcast I saw this message:

Note: If the Webcast system does not detect encoder traffic 30 minutes into the broadcast, the event will automatically terminate.

I'm assuming that means 30 minutes into the scheduled time and not the 2-hour pre-buffer, right?

This is a good question. Did you ever get this answered? I've got to believe its after the actual broadcast start time.