Multiple Systems Extension

Good day,

I’m running Freepbx 4 differents sites.

One is my main site. My head office.
All the 3 others, are store that we own.
Right now, my head office and one of my store are connected with a trunk. Call between them work perfectly.
I will connect a trunk between the site2 and 3 to my head office.
Will site 1, 2 and 3 be able to call between them, passing through the head office, or I need to use a trunk between each sites?


I think your solution is: