Federal support laws

I have been doing some research on the federal laws, they cover or govern the state laws. My problem is I, my current wife and three children live in North Carolina (for over 9 years now). My ex-wife and two children live in Nevada (for over 6 years now). My ex-wife and i were divorced in Calif. 14 years ago.

Recently i received a modification of the support amount, it was maximized by a Calif. court. I can not find anywhere in the federal law or state law that this is illegal.

Should the support amount not be set by a state in which the ‘obligee’ or ‘obligator’ live?

Is this specified in a federal law anywhere?