Can you explain theory to me and confirm or correct my learning so far? I plan on getting ADC cameras when the new ones come out and when we work out the kinks on the LVM.
I though one of the benefits to a IP camera is that you don’t have to do Home Runs to the NVR. For example, I could do 1 run from the back of the house where the NVR is, to the front of the house, have a switch and then make 3 runs to 3 cameras to the switch?
So why do NVR’s have multiple ethernet ports? Couldn’t they just have 1 and installers just buy switches as necessary?
You are correct. They don’t need more than 1 ethernet port and many NVRs only have 1 ethernet port.
If they have more then it’s for convenience and/or to decrease network load. For example, the ADC-SVR210 has a port for cameras and a port for uplink (internet). That allows all the constant heavy camera traffic to be isolated from the rest of your network and enter the SVR through the cameras port. Traffic only needs to go through your main network when it’s being uploaded or streamed to Alarm.com. You would still need a switch to connect multiple cameras through the cameras port.
When using 3rd-party cameras with Alarm.com, I think they may be required to go through the cameras port. I would have to check on that to be sure but the 3rd-party camera docs say it’s the only supported network topology. With 3rd-party cameras the SVR actually converts them from their native protocol (e.g. ONVIF) to Alarm.com’s protocol.
If you’re only using Alarm.com cameras, you aren’t required to use the cameras port but it’s still recommended for network efficiency.