Connecting to Private IPs from Wireless clients

I have my network "insulated" from comcast (and any other ISP), but I seem unable to connect & manage the Cisco dp-3939B unless I connect to one of the native wireless networks or attach to one of the local ethernet ports...

I have looked, but have been unable to find out how to enable this functionality... Should be pretty straightforward, or at least was when I had ATT as my ISP... 

Appreciate any assistance, Many Thanks in advance;