WAN: HOW TO SETUP WAN BETWEEN TWO LOCAL OFFICE LANS
A wide area network (WAN) is a telecommunications network or computer network that extends over a large geographical distance. Wide area networks often are established with leased telecommunication circuits.
Business, education and government entities use wide area networks to relay data among staff, students, clients, buyers, and suppliers from various geographical locations. In essence, this mode of telecommunication allows a business to effectively carry out its daily function regardless of location. The Internet may be considered a WAN.
If you wish to connect two local area networked offices then you will need to setup a vpn tunnel to create a wan. That is basically a local area network with two offices on the same internet. If you are going to setup one, your first bet is to consult your internet provider to see the available options.
So here are some options for connecting two lans via vpn tunnels.