[p2p-hackers] IPv6 and NAT

[coderman]

On 5/24/05, Wes Felter <wesley at felter.org> wrote:
>...
> Sure, if you can afford to write an *entire network stack*. (But then, I
> guess a secure, reliable P2P messaging layer that can bust through every
> type of NAT/firewall is almost as complex...)

And also accept the fact that scheduling in userspace for that stack
(tcp/other timers) is going suck.  We've been down this road with TCP
over UDP in userspace, etc.  Have you tried using high resolution
timers on windows in userspace?  Not pretty.


> I'm pretty sure Java VMs just use the OS's IPv6 stack.

That is exactly what it is doing; the sockets API for IPv4 or IPv6
works fine in java, but that is all it is using; the stack and
implementation resides in kernel land...

One thing I always liked about Solaris/HP-SUX is that you could
configure additional stacks via STREAMS and use XTI to bind to
whichever stack you wanted.  The berkeley sockets always defaulted to
the system stack but XTI/TLI let you pick (via the device path given
to t_open).

This is still running in kernel land though, and last time I checked
you needed to cough up $50,000 or more for a mentat TCP license for
additional stacks.