vpn connection between dynamic public ip and a static public ip

[reedone816]

hi i'm newb in router configuration, so need help on this.

i got two fortigate, one as the main 800c and one as the branch 60d

the main has static ip address, and the branch has dynamic ip address and behind firewall/isp router.

can anyone help me how to create the connection? without using dyndns or similiar?

i've been told to use dial up for the main, and site to site on the branch, but don't know how to do that...

thanks