SSTP or Secure Socket Tunneling Protocol is a new type of VPN connection that uses port 443. SSTP is part of Windows Server 2008 RRAS (Routing and Remote Access). On the client side, you need Vista SP1.
The setup is very simple. Just setup RRAS on Windows Server 2008 and follow the wizard. When you setup the VPN, ports will be created for PPTP, L2TP and SSTP:
The RRAS wizard does not help you with the required certificate. It does not matter how you get the certificate (online CA, public CA, ...) but you need to make sure you store the certificate in the Computer store (Personal):
On the client side, make sure that the computer (not the user) recognizes the SSTP certificate. If you used your own CA, make sure that the CA certificate is in the Trusted Roots store of the computer. Then make a new VPN connection and select SSTP in the Networking tab:
That's it. You can now establish a VPN connection using only port 443 and forget about those typical NAT problems with IPSec VPNs or PPTP passthough issues.
