> No imagination required. P2P works fine if at least 20% to 30% have ports open inbound. 70%+ need not have open inbound ports. Where this could theoretically

> No imagination required. P2P works fine if at least 20% to 30% have ports open inbound. 70%+ need not have open inbound ports. Where this could theoretically be a problem is if a specific sub-set of CG-NAT users were the only people seeding and downloading something. "Seeding"? "Downloading"? I think applications besides BitTorrent could be invented and become popular. Even now, existing things like SIP and WebRTC would probably be much less onerous. > This non existent problem can be worked around using a VPN mesh. Tinc is an open source VPN that operates in user-space and while not as fast as Wireguard it can do things Wireguard could never dream of such as user space mesh routing, always discovering the shortest path. So you're introducing another layer of software because the underlying network does not have the functionality available (just like STUN/TURN/ICE had to be invented to deal with NAT). Here's another idea: have IPv6, and if folks want to have end-to-end encrypted communications, start up an IKEv2 process (that opens a hole for its port via UPNP/PCP), and we have IPsec (which is built into most OSes anyway) encrypted communications opportunistically enabled.