I went into SERVICES > USB and enabled all the USB supports, saved and applied.
From the laptop I added a new printer, added as a network printer. When searched, the printer did NOT show as listed.
Selected as "Add a printer using a TCP/IP address or hostname. Typed in the IP address for the gateway on your computer.
To determine the correct IP address for YOUR situation, sign on to the router, select STATUS, then select LAN, in the box at the top of the screen which contains the MAC address, IP address, subnet mask, Gateway and Local DNS the IP address box contains the IP address you want to use. Gateway may well be blank.
If the router is not found, it will ask you the type of card you are using, generic will do.
At this point select the make and model of printer from the choices provided. If your printer is not listed, install the printer driver from the printer manufacturers website and say "Have Disk" then point to the location where you installed it. Select finish and print a test page to confirm.
Consider it this way...To reach the USB port on the router it needs to know the router IP. Once it knows the router IP it can see the printer hanging off of the USB port.
Hopefully, this is a little bit fuller explanation and will be found useful.