Because - as I understand it. MSN Messenger uses H.323. H.323 is a bastard to use through firewalls and even worse through a Masqueraded IP address as it negotiates random UDP connections that the firewall won't expect and also embeds the ip address of your PC in the data part of the packet. The masquerade or NAT function of the firewall cannot detect this address and won't translate.
Net result - it doesn't work.
Solutions (partial): 1. Get an H.323 proxy and hack into the firewall - not easy and I am hoping that Astaro will add this to their product in time. 2. Use a VPN to the other party 3. Open up the firewall - and you may need to port forward from the outside.
Someone may be able to correct my limited understanding of how things work with H.323 - but that is how I understand it.
Because - as I understand it. MSN Messenger uses H.323. H.323 is a bastard to use through firewalls and even worse through a Masqueraded IP address as it negotiates random UDP connections that the firewall won't expect and also embeds the ip address of your PC in the data part of the packet. The masquerade or NAT function of the firewall cannot detect this address and won't translate.
Net result - it doesn't work.
Solutions (partial): 1. Get an H.323 proxy and hack into the firewall - not easy and I am hoping that Astaro will add this to their product in time. 2. Use a VPN to the other party 3. Open up the firewall - and you may need to port forward from the outside.
Someone may be able to correct my limited understanding of how things work with H.323 - but that is how I understand it.