Draytek VigorPro 5510 Series Quick Start Manual page 23

Free trial: if it is the first time that you register the service, please use the option.
Formal edition with license key: you can extend the license valid time manually.
3. In the following page, you can activate the AV/AI, AS and/or Web content filter service at
the same time or individually. When you finish the selection, please click Next.
4. Now, the web page will display the service(s) that you want to activate according to your
selection. The free trial of AV(DT-DT) is three years; Anti-spam is one month; and the Web
content filter is one year (till 2009/12/31).
5. Check the service status in the Defense configuration >>Activation.
VigorPro 5510 Quick Start Guide 17