the alleged evils of NAT, was Rate of growth on IPv6 not fast enough?

Mark Smith nanog at
Tue Apr 20 16:56:12 CDT 2010

On Tue, 20 Apr 2010 18:38:33 +0200 (CEST)
Mikael Abrahamsson <swmike at> wrote:

> On Tue, 20 Apr 2010, John R. Levine wrote:
> > Skype video chat, all the time, works fine.  Don't remember about file 
> > transfer.
> Whenever I am behind NAT and talk to someone else who is behind NAT skype 
> seems to lower the quality, my guess it's because it now bounces traffic 
> via another non-NATed node.

I think that means skype will be ported to IPv6 pretty quickly. CGN/LSN
is going to dramatically reduce the number of 'super nodes' with public
IPv4 addresses to relay calls through. That'll be particularly
unfair to people in Australia, because here we have a per-month quota
system e.g. 20GB of downloads and/or uploads a month. I wouldn't want
my quota being chewed up by lots of other people's phone calls.

> These kind of applications work best if there is at least one non-NATed 
> party involved, especially for video etc.
> -- 
> Mikael Abrahamsson    email: swmike at


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