True router mode for PMP450

Hello, We are having the time old trouble of trying to get our Mikrotik to use the 450 SM to properly pass our traffic to our tower.  We have turned off nat to put in bridge mode, which to some of what I have found seems to put it in router mode, However am I missing something because Other readings have stated a specific "Router Mode" Is this in another model that the one I have per chance? At this time I have to VPN link the Mikrotiks in order to get traffic to pass properlly but this bogs down the CPUs of the routers after a certain limit so would really like to have this done through the radio correctly.