VPN Problem? Please help

hello, i am new to setting up VPNs and have just followed this guide

YouTube - ‪2008 and Vista - Setting Up NAT and VPN Server - Part 3‬‏

parts 1, 2 and 3.

When trying to connect to the VPN server (from a seperate connection i am tethering from my iphone) i cannot connect to the server. I am using the internet IP address as the server and i can ping this ip from a remote server (again my iphone) but it wont connect??

Ive been at this for a week now, and no luck. I know i can use third party software but choose not to, as im also doing it for the experiance.

Any ideas?

any help much appreciated,

Cheers

update: just trided VPN passthrough on my dynalink RTA1025w by forwarding ports

1723 TCP to 192.168.1.2 (server running the VPN)
47 (GRE) to 192.168.1.2

still no go?

at the moment for testing purposes only the server is running on a wifi NIC