L2 VPN Channel on Windows xp?

Question

VPN

Hello!
The Internet comes in a 3G whistle plugged into a Chinese iPhone via a USB hub, distributing to the D-Link DIR-300 via Wi-Fi. We need to organize an L2 VPN with a laptop on which WinXP SP2, as a backup channel we drive carrier pigeons with attached flash drives! How, then, to use the network and set up a VPN? Tell me please!!!

Answer 1

1. Why is the whistle not plugged into the computer?
2. WinXP supports L2TP, L2TP ipsec, PPTP, set up and use.
3. What is the need for L2?