[GnomeMeeting-list] Re: GM without forwarding any port

["Bruno Hertz" <brrhtz yahoo de>]

Timothée Lecomte <timothee lecomte ens fr> writes:

> Damien Sandras wrote:
>
>             Notice that if you are calling a GnomeMeeting 1.2.x user 
>             * who is behind NAT, but configured (symmetric NAT with port forwarding
>             and STUN, or other type of NAT without port forwarding and STUN only),
>             or 
>             * who has a public IP, 
>             it will work because the remote GnomeMeeting will detect you are NATted
>             and it will transparently fool your NAT router.
>             
>             That will only work if the remote user you are calling is using
>             GnomeMeeting 1.2. It won't work if he is using GnomeMeeting 1.0 or
>             earlier, or if he is using Netmeeting. He can be behind NAT, but
>             configured appropriately.
>             
>             The problem will only happen when calling another user in the same case
>             as you (ie unconfigured symmetric NAT).
>
>         Great !
>         The people I wish to call are at home, behind a NAT that I can
>         configure. So, I just have to set it up, and it will work...
>         Can you confirm that both sides will be able to call the other ?
>
>     Only *you* will be able to call them, because your port listening for
>     incoming calls won't be reachable from the outside.
>
> So the FAQ formulation is not really relevant :
>
> "If you are using GnomeMeeting 1.2, and are calling a GnomeMeeting 1.2 user, only one of the 2 GnomeMeeting users needs
> to be configured to go through NAT. The configured GnomeMeeting user will transparently help the non-configured one to
> go through the NAT router."

If that's the FAQ entry, it's actually not very clear. Of course, if
you call somebody, your IP packets must reach her/him. If he's behind
a NAT/firewalling router, that router must hence either provide proper
port forwarding or application level routing of the VoIP
traffic. Apparently, GnuGK could do the latter, but I myself never
tried that and can't give any details on that one.

Afaik, the thing GM is great on is that it works behind NAT *at
all*. I.e. H323 as well as SIP do IP address exchange on application
level, which of course leads to nonsense when clients are on LAN with
nonroutable, nonpublic addresses like 192.168.0.123. So with regular
H323 clients, and without taking extra measures, there's no chance at
all you could place a call from a private network into the
internet. Now with GM this even works with both clients behind NAT,
which is very great. It doesn't however relieve you from the work to
still provide proper routing, port forwarding or application level,
for your bare IP traffic.

I think if you could install GnuGK on that FTP machine you mentioned
you should really be fine. If the machine has a public IP address,
that is.

Regards, Bruno.