Can I Control a Network implemented by MasterServer ?

Hi all

I don't have information about using MasterServer in Unity . i wana know can i implement a network by it and then say exactly what is subnets and some time change subnets , some time do multi cast . some other times do broad cast to another ip range and ...

i think this work are easy with UDPClient but i want to know can it be done by masterserver ? i used nat .

tnx