behind the firewall.. does not work…
http://www.placid.tv/pie.php?page=FrickinPPTP
What does Frickin PPTP do?
Frickin PPTP Proxy allows a Point-to-Point Tunneling Protocol (PPTP) client to connect to a PPTP server through Network Address Translation (NAT).
Why do I need it?
PPTP uses a TCP connection on port 1723, which is referred to as “control channel”, and a variant of generic routing encapsulation (GRE) for the actual PPP data.
When using TCP connections you can easily tell two connections apart by looking at their port numbers, with GRE this is not possible since it has no ports.
The PPTP server is able to multiplex between connections by looking at a call-id inside GRE packets. These call-id’s are communicated over the control channel before a GRE tunnel is created.
When connecting through NAT all connections will originate from the IP of the NAT gateway and multiple PPTP connections are not possible without a proxy.
Download
The latest version of Frickin PPTP is avaiable on sourceforge.net.