Timecapsule Port Forwarding

Hi, I'm trying to figure out how to port forward on the timecapsule. Every manual and how to guide I've looked at shows a port mapping option on the advanced tab of the Airport Utility. I don't have that option on mine. The only options displayed are Logging and Statistics, Mobile Me, and IPv6. I'm using the 7.4.2 firmware. I believe that's the latest.

I figured it out if anyone else runs into the same problem. Connection Sharing under the Internet tab must be set to "Share a public IP address" followed by "Enable NAT Port Mapping Protocol".