*edited to be more specific
I have two mobile trailers and two retail stores. The trailers travel around the country as a mobile retail store. Each location is running a IP scheme as 192.168.1.xxx, 192.168.2.xxx, 192.168.3.xxx, 192.168.4.xxx respectively. 99% of the traffic is internal since all the web and database servers, POS systems, etc are on board. Using a CradlePoint MBR1400 wireless router access the internet via mobile broadband. But the internet is mainly for just checking email, and music. No VPN or anything else is used.
Every once in a while, to expand the number of POS systems and the number of customers we can process, two trailers or a trailer and a retail store need to work together.
Being that each location can operate independently they run their own databases. So when we bring them together we only run one database server, one web server. on the "master" trailer (say the one running 192.168.1.xxx).
Since the POS system is all web based, the slave trailer would simply point to the master web server 192.168.1.3.
So I simply need to know how to setup routes, so on the slave (192.168.2.x) I can type in 192.168.1.3 and reach the master web server.
I know CradlePoint allows RIP, OSPF, BGP, and static routes. Is there any way I can get these two networks talking to each other?