WAN Rollout/WINS

Currently I have LAN’s in each of my 4 remote locations. I intend on using the single master domain model to make one network that spans across our frame relay network.

Each remote location is on a different subnet. Therefore, do I need to setup WINS on the BDC’s that I will install into each facility? If so, which one do I need to make the push or pull partner.

Also, in theory I know that this whole domain thing is supposed to work, but does it really? Are there any snakes in the jungle that I should look out for?