[Freeswitch-users] DNS SRV Failover - How about incoming?

I think I understand how to use DNS SRV for failover for outgoing calls, if the phone supports it, it will try the next lower priority entry upon.. no response. So that works fine for outgoing - it will auth for the call. What about incoming to the phone, via FS? If devices are behind NAT then is there any way to successfully get the calls back to them? Would it make sense to have the registration mirrored across the servers that may be failed over to? Is there more information about this on the wiki somewhere? Thanks, Avi Marcus