What is the best way to connect to VMs to each other

Hi,

I Have one Win2012 server created under subscription1.

I have a Win7 VM created under subscription2. Added as a Visual Studio subscription.

Both machines run on separate networks. 

What would be the best way to allow them to be connected on the same network.

I basically need to simulate/develop a client/server architecture.

Thanks for any advise.

Olivier