By placing an AsusWRT router after Vilfo, your AsusWRT router can be used to extend the wireless network of Vilfo.
Turning your AsusWRT router into an access point

Log in to your Asus router
Navigate to Administration - Operation Mode
Select the option Acces Point(AP) mode
Click Save
On the new screen, click Next
On the new screen, click Next
Connect a network cable between LAN port on your Vilfo and the WAN port on your AsusWRT router
To make future changes in AsusWRT you will need to do so using the IP address assigned to your AsusWRT router by Vilfo.
Note! If you choose to use your AsusWRT router as an access point, you may want to disable the Wireless network in Vilfo.