You should be able to tell by going into whatever software the cameras use to stream/record video and see if the video streams show up. Aside from that, you can log into your WiFi router, generally 192.168.1.1, but may vary by router/manufacturer. Once logged in there is usually a place to see what devices are currently connected under the WiFi section. Again, this varies from router to router, so specific instructions would be hard to give. Just look up your router on Bing and you should be able to find login information.