FreePBX run on Dual WAN router

If I need to run a Dual WAN router, is there any setting need to be consider on the freepbx?
like we register the WAN IP for the phone system, now we are going to setup another WAN to run load balance, is this work?

This sounds like a total mess. Maybe asterisk 12 with pjsip can handle it by carefully designing routing table on the dual wan router and load balance by designating particular wan interface for particular trunk. I wouldn’t want to mess with it though.

For asterisk 11 or lower you better only use one wan interface for all your asterisk traffic or the asterisk will be totally confused about where to send sip and rtp traffic.