How to make one speaker talk in multiple conference rooms simultaneously?

Hello,

we need broadcast a single speaker to two conference rooms simultaneously.
The speaker should call up a number and then land into both conference rooms, so that people in both rooms can hear him.

I played with paging a bit, setting the conference room numbers as the target numbers, but with no success.

Could anyone help with some tips on possible configuration of making one extension to connect to multiple conference rooms at the same time? One-way speech would be enough (speaking only)

Not possible without manual configuration, but most phones support a conference call that would allow the speaker to manually call into both conference rooms and speak at the same time.

This is the exact definition of Paging. What problems did you have getting paging to work for you?