VPN port redirection (windows xp & server 2003)

hello, if my office blocks VPN outgoing connection (port 1723), is it possible to do this?

1)Pc1 - VPN client dials localhost port 1723
2) Pc1 - TCP redirection software redirects that connection to remove VPN server port 80
3) VPN server - accepts that connection
4) VPN server - TCP redirection software redirects that connection to itself to port 1723

I have a TCP/UDP redirection software. I telnet to those ports, seems connection can be established, but when i try to VPN-dial, I get "Error 800 : Unable to establish the VPN connection".

is VPN not TCP connection ? or is it much more complicated than that?
Who is Participating?

A (Windows) PPTP VPN establishes communication by calling into port 1723 but the actual VPN traffic is carried over protocol 47, GRE.

GRE (Generic Routing Encapsulation) is an IP protocol, not a port. TCP and UDP are also IP protocols. The only port you need to open is tcp port 1723 (pptp). If you cannot find the GRE protocol mentioned by its name or by its number (IP protocol 47), look for things like PPTP pass-through mode or VPN pass-through mode in firewall/router.

Even you can try to open up UDP Port 47 GRE as well (as a seperate rule) for some lower level routers without any pass-through mode.

You might be doing "IPSec over L2TP" over VPN through UDP 1701....
More information
VPN servers and firewall configuration
Abhay PujariCommented:
VPN is end to end connection between server and client. When client makes a request, it goes to server and then server responds. bith client and server gets connected after acceptence and approval from server. This happens across standard TCP ports. I am not sure whether you can define custom ports for VPN or not. VPN is TCP connection.
You cna request your office to open the port for you.
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