I understand that 4GLTE uses double NAT technology and as a result remote access/port forwarding will not work. I just purchased a 6620L and want to know if I set it to CDMA or Global, will it also use the double NAT technology for use single NAT technology allowing remote access.
As long as About Jetpack > Internet Status shows an IPv4 IP address that starts with 10 or 100 then the Jetpack is connected to Verizon's private network and subject to their private network rules. Port filtering does work on the Jetpack, however, if Verizon's private network is blocking those ports then you're Jetpack will never see them.
Basically, you have four options to go around Verizon’s private network: