Yes, but regardless of whether they use names or numbers, they still cannot get "public reachability" (a public IP address and allowance of unsolicited ingress traffic) without either getting a publicly reachable IP address (ISP's in the US call this a "business class" account) i.e. option 1 or somehow involving at least one computer that already has public reachability i.e. option 2 or 3.

At least, _I_ know of no other way.

If you know how to create public reachability without giving the user a publicly reachable IP address or involving a computer that already has public reachability, please develop and release the code; I think you are a networking genius and have done the impossible!

In any event, my point is that it's probably better that the computer that already has public reachability be owned and controlled _by the user_, not some third party "provider". The user should only need one provider to communicate over the internet: their ISP. I say just give users a publicly reachable IP address: "upgrade" their account with the ISP to allow unsolicited ingress connections.

A myriad of communications and data synchronization solutions will follow. I reckon developers would love to write code for an end-to-end network. It would certainly be more functional that one where eevrything must be done via HTTP through a "web browser".

OCaml NaCl and dnscurve. Nice work! I hope your project succeeds!