[asterisk-dev] Problems with Firewall

[Karsten Asche]

> -----Ursprüngliche Nachricht-----
> Von: "Steve Totaro" <stotaro at asteriskhelpdesk.com>
> Gesendet: 02.02.09 18:06:27
> An: Asterisk Developers Mailing List <asterisk-dev at lists.digium.com>
> Betreff: Re: [asterisk-dev] Problems with Firewall


> On Mon, Feb 2, 2009 at 11:50 AM, Steve Totaro
> <stotaro at asteriskhelpdesk.com> wrote:
> > On Mon, Feb 2, 2009 at 11:43 AM, Karsten Asche <K-Asche at web.de> wrote:
> >> Hi @ all,
> >>
> >> IŽm programming a Softphone under Windows.
> >> At the moment I have the problem if I do a call,
> >> the SIP Session will be created succesfully but sometimes
> >> the speech from my XP System will be send but after send to server
> >> it will be blocked.
> >> The curiosity is that under Vista this problem doesnŽt happen.
> >> Both Clients run through the same Firewall.
> >> If i Do the call on my XP with SJPhone it works fantastic and after
> >> compare the sent pakets with my sent pakets there are no differences.
> >>
> >> What could it be?
> >>
> >> Regards
> >> Karsten
> >>
> >
> > Port forwarding, NAT, two phones on 5060?
> >
> > --
> > Thanks,
> > Steve Totaro
> > +18887771888 (Toll Free)
> > +12409381212 (Cell)
> >
> 
> Maybe explain the topology a bit more.....
> 
> If your softphone is not sending an occasional keep-alive through the
> firewall, then the firewall may take i as an unsolicited packet and
> block it.  Different firewalls/routers have different timing, but you
> need to be sending keep-alives to keep the dialog open when the phone
> is not in use.
> 
> Just a thought....
> 
> -- 
> Thanks,
> Steve Totaro
> +18887771888 (Toll Free)
> +12409381212 (Cell)
> +12024369784 (Skype)
> 
ThatŽs a try worth. I donŽt send any keep alive.

But why it works fine about Vista?

ThatŽs the way I work with the asterisk server.
I send the Sip message through the Proxy and then
I use the IP:Port Information from the SDP Packet I get from
Server. IsnŽt it so that the server makes a hole to the port in the 
SPD Packet?
Because the SJPhone takes the same attributes for Port an IP