Good advice from ebrind
I'll add to it:
- what IP address does your time capsule have?
If your CenturyLink provides NAT and your Time Capsule is also setup for NAT, you will need to reconfigure either the TC or the CenturyLink to bridge mode and set the port forwarding in the device providing NAT.
- do you see any activity in the VPN Log?
- Your VPN server address which you set in your laptop should be the public address of your network, not the LAN address
- If you do make a successful VPN connection, don't expect to see the server like you do when you are on the LAN. If the LAN address of your server is 10.1.10.2, you'll need to connect to: afp://10.1.10.2 (after a successful VPN connection)
- Lastly, do you need VPN? If you just need access to your files from the server, you can do this without VPN. Depending on your security requirements, you can simply map port 548 and access with: afp://[public-ip] or use webdav with SSL.