What are the IP addresses for Netgear router and your PC?
Are you able to see the SPA3102 from your router? I mean if the SPA3102 is in the attached device list on the web page of router. Certainly you should also see your PC in that list.
In order to access SPA3102, router, PC and SPA3102 need to be in the same subnet. i.e. 192.168.1.x. I assume you use the default subnet mask 0.0.0.255.