how to share disk with samba to Mac on another network (High Sierra)
You need the following ports:


UDP 137/138 
TCP 137/139/445


If you are attempting to expose your SMB shares over the Internet, it's not going to work.  The UDP ports are not routable over the public internet.  

You either need to have a private link between the two sites or a VPN.  Even with this, it's a very inefficient method.  You are far better off with a cloud based solution.