[zanny]

> One wonders if every ISP customer were willing to pay the extra fees (if any) and requested a publicly reachable IP address, could the ISP's meet the demand?

Well no, that is why all ISPs are using DHCP. Most offer static IPs for extra fees, but like fractional reserve banking that only works if all possible subscribers aren't trying to claim unique IPs each.

[yperr_string]

You may have misunderstood what I mean when I use the term "publicly reachable".

It is not only the static nature of the IP address that make it more suitable for peer-to-peer.

It is the ability to accept unsolicited inbound connections on any port.

The key word is "unsolicited".

Essentially, the user pays extra for the "privilege" of less stringent firewall rules.