Any other methods to join players on Black Ops III with different NAT Types? Or do i HAVE to portfoward my PS4?

Me and my cousins have PS4s and Black Ops III, and i am unable to play with them due to our NAT Types being different. I have a Moderate NAT, so i should be able to join other players, but i do not know my cousin's NAT type. Any tips?
(Sorry if the word "NAT" was said too much)

Yami2017-10-18T00:24:42Z

You can out your console in DMZ, but port forwarding is safer. Pretty simple too.