Anybody know how I can connect through RDP to a computer that is using Verizon jetpack? I was hoping DDNS would work. Port failed though when I do a check.

You need to setup port forwarding for port 3389(default remote desktop port) so that connections coming to port 3389 can be forwarded to port 3389 on the internal IP address of your computer.

Verizon jetpack may not have a default port forwarding rule for remote desktop. You should consult Verizon community forum or support to set it up.