Why would MacBook Pro indicate "not on same network" as iPhone...when that is not the case? I have a new MacBook Pro (2015) from apple and I am trying to link with my iPhone so I can make calls from the laptop. I have done this before, with my iMac and other laptops but I keep getting a message (see below) that they are not on the same network...but they are!!! Any thoughts?
Network might me blocking required protocols.

UDP ports 500 and 4500 are required for Wifi Calling.

Other ports and protocols might be needed.

There is a list here.