Do I need to purchase additional license to use site-to-site IPSec VPN tunnel? Or only hardware without additional license able to do it?---That's one advantage of Fortigate no need to buy separate license for VPN just to work.
Will the bundle work across continents? I mean, if I buy it from China, will it work outside the China, for example, Asia (Mongolia, Korea and Japan) and Europe (Russia and Germany)?---IMHO, no issue for this.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.