RE: WG Last Call: draft-ietf-v6ops-unmaneval-01.txt

["Christian Huitema" <huitema@windows.microsoft.com>]

A couple of quick points regarding Teredo:
 
> >    In automatic tunnels like [Teredo] and [6to4], the bulk of the
> >    traffic between two nodes using the same technology is exchanged
on
> >    a direct path between the endpoints, using the IPv4 services to
> >    which the endpoints already subscribe. By contrast, the
configured
> >    tunnel servers carry all the traffic exchanged by the tunnel
client.
> >
> > <MB> Is "direct path always possible in all cases between Teredo
nodes?
> > </MB>
> 
> It isn't and this should be reflected here.

Actually, in the current design either all traffic will go on the direct
path, or no traffic will be exchanged at all.


> > ...
> >    by many applications, e.g., networked games or voice over IP. The
> >    experience shows that most recent "home routers" are designed to
> >    support these applications. In some edge cases, the automatic
> >    solutions will require explicit configuration of a port in the
home
> >    router, using the so-called "DMZ" functions.
> >
> > <MB>only works for one single node. Moreover, it should be noted
that
> this
> > explicit configuration is completly out of the _unmanaged_ goal.
> >
> > Suggesting text:
> > using the so-called "DMZ" functions". These cases are obviously out
of
> > scope of the unmanaged network scenario and only work for a single
node
> > behind the NAT.
> > </MB>
> 
> Good point.

I agree that in the absence of automatic support through UPNP, DMZ
functions are indeed not your typical unmanaged service. But the point
is at least partially incorrect. First, it is possible in some cases to
use automatic procedures to "DMZ" a port (e.g., using the UPNP "internet
gateway device" service). Second, the procedure that absolutely work for
more than one node -- just pick a different port for each node. 

In any case, the work done in the MIDCOM working group shows that the
number of symmetric NAT in the market is rapidly decreasing. See
draft-jennings-midcom-stun-results-00.txt

-- Christian Huitema