We can distinguish two kinds of data streams between the system and passive entities.

The first type must enable the system to obtain teachers and students groups constraints about teaching from the NPP. These constraints are transmitted by the courses manager.

This leads to the following collaboration diagram between the NPP and the system.
Collaboration NPP/system

The second type must enable the system to be informed of the state of the rooms constraints. This information is transmitted by the rooms manager.

This leads to the following collaboration diagram between rooms and system.
Collaboration rooms/system

And there are possible interactions with each active entity: