[Opensim-dev] STUN for OpenSim?

[Stefan Andersson]

Ah, I was under the (wrong) impression that STUN incorporated UDP hole
punching[1] support.

Then, let me rephrase my suggestion; would UDP hole-punching be a viable way
of approaching this, and has anybody worked with that?

/Stefan

[1] http://en.wikipedia.org/wiki/UDP_hole_punching

> -----Original Message-----
> From: opensim-dev-bounces at lists.berlios.de [mailto:opensim-dev-
> bounces at lists.berlios.de] On Behalf Of Infinity Linden
> Sent: den 15 juli 2009 00:49
> To: opensim-dev at lists.berlios.de
> Subject: Re: [Opensim-dev] STUN for OpenSim?
> 
> STUN is used by a client to establish it's routable IP address. in
> other words, the address a peer would have to connect to in order to
> have a chance at crossing the NATting firewall.
> 
> DynDNS can help with this too, but is used to do name resolution.
> 
> they're effectively used for different scenarios. DynDNS and STUN can
> both be used by systems which are given dynamic IP addresses from
> their ISPs. depending on the type of fabric you want to use, either
> might be useful. if you're talking about software that starts up,
> registers it's IP address with a service, that's STUN. if you want to
> publish a DNS name and have it route to your NATting firewall even if
> you're on the wrong end of a dynamic IP address, thats DynDNS.
> 
> for what it's worth, STUN considered to address a subset of the
> problem of maintaining stateful application layer sessions across a
> NATted firewall. RFC5389 describes the problem in a little more
> detail, along with more generic solutions. (
> http://tools.ietf.org/html/rfc5389 )
> 
> RFC5389 describes a series of techniques for UDP messages to
> successfully traverse a firewall that are not found in DynDNS.
> Ultimately, a good read of 5389 and practical experience with your
> firewall will do you a load of good.
> 
> -cheers
> -meadhbh
> 
> On Tue, Jul 14, 2009 at 3:15 PM, Mojito Sorbet<mojitotech at gmail.com>
> wrote:
> > If you are running OpenSim behind a NAT router, you are going to have
> to
> > configure the routing in some way, regardless of whether STUN, or
> even
> > TCP, is used.  That is because the connection is originating outside
> of
> > the firewall, and the whole purpose of firewalls is to not let that
> > happen, except in carefully prescribed circumstances.  Same thing
> > applies to VOIP.
> >
> > The problem of people not being able to find your IP address has
> already
> > been solved by services such as DynDNS.
> >
> > On Tue, 2009-07-14 at 07:57 +0200, Stefan Andersson wrote:
> >> One of the main shortcomings of the linden-legacy model is that
> >> OpenSim does not work well (as in simple and consistent)  from
> behind
> >> NATs and several home routers.
> >>
> >>
> >>
> >> I was thinking, if something like STUN could help us overcome this?
> >
> >>
> >
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