"is anyone aware of any estimations of fraction of Internet users
who are behind firewalls and NATs?"
So, this question piqued my interest. Figured I'd take a
bash at estimating NAT usage using the online QuakeIII community
as a reference. Cobbled together two Q3 servers, logged client
port numbers, and looked for NAPT 'fingerprint' of clients coming
in on unexpected UDP ports (Q3 client side seems to always use
27960 if not mangled by NAPT). Using an indirect, and somewhat
arm-wavy method I estimate between 18 and 19% of the players
on my servers were behind NAT boxes. A bit more discussion is
How about for business users? If the assumption can be made
that most Q3 players are home based (which would probably
have a lower incidence of NATs) ~20% sounds high. Of
course that could be because of sevice providers.
But does anyone have a better idea for business users?
Kyle Lussier
www.AutoNOC.com