Peering, interconnecting two freeswitch servers : how to ?

[biloa]

Hi Everyone,
I'm too new to the Freeswitch and Pfsense config.
I plan to peer two freeswitch servers with the below :

server 1 :
public ip address , that is : 1.1.1.1
two extensions : 1005 and 1005

server 2 :
ip address : ringo.dyndns.org

two extensions : 2005 and 2006

Let me know how to interconnect servers for making free sip calls one to another.

Regards and Thanks !!!

Biloa :)