I travel a lot, and I've become accustomed to accessing my home network via SSH, VNC, etc. It appears uPNP and PMP are unsupported by CGN. So, without a publicly-routed IPv4 address, I'll be unable to reach devices on my home network from an IPv4-only connection, such as the one provided by my cellular carrier. (which also appears to be behind some kind of NAT, by the way)
If the ISP isn't willing or able to sell me an IPv4 address, what alternatives do I have? I'd be willing to pay a small monthly fee for, say, a VPN service that would allow me to accept incoming connection requests on a range of ports on their internet-facing IPv4 address. Does such a service exist?