I have a VPN concentrator behind a NAT router (model 2621XM). The VPN concentrator is at the edge of my lab network. While travelling, I want to be able to use a VPN Client on a Windows box to traverse my NAT router and connect to my VPN concentrator so that I can then access my lab network remotely. I now that I need to create a static NAT translation in my IOS router. What ports/protocols do I need to statically map?