I was at a small client yesterday and ran into a puzzling situation. He has an eight camera IP survielence system at his store. This is a small store with only one Pc in addition to the camera system. Up to a week ago, they couldn't get any Comcast internet service so they used an ATT Air card installed on their Sonicwall firewall/router for web access. That worked fine.
Since Comcast came in, they installed their router in front of the Sonicwall and the PC has continued to work properly with web access going through Comcast.
The original camera system installer couldn't get the system viewable remotely (probably due to the limited bandwidth) so he just left it viewable locally at the NVR. I was called in to get them viewable remotely over the Comcast connection. I noticed none of the camera's network ports showed a link light or blinking LED's showing data activity. I checked the NVR and updated it's network settings to work with Comcast. There is a built-in POE switch on the back of the NVR. I viewed the cameras on a monitor connected to the NVR so I know they are connected and recording. The network port for the Comcast connection on the NVR doesn't have any LED's lite either. I checked the Comcast router and the NVR cable does not have a Link Light and does not show activity but I can view them remotely on my smartphone.
With my Windows 7 laptop plugged into the Comcast router, I can ping and log into the DVR without a problem.
I called the NVR vendor and he had never heard of a situation like this. The cabling is all Cat5 and appears to be terminated properly. I put a cable tester on the cable from the NVR to the Comcast router and it passed a cable test. Any idea why there are no link or activity lights?