Reddit reviews BV-Tech 18 Ports PoE/PoE+ Switch (16 PoE+ Ports | 2 Gigabit Ethernet uplink) - 19" Rackmount - 130W - 802.3af/at

I have one of the BV Tech ones from amazon, I've only had it since Dec but no problems.

I have this one:
https://www.amazon.com/BV-Tech-Gigabit-Ports-Switch-Uplink/dp/B0754P9KLN/ref=sr_1_7?keywords=bv+tech&qid=1559295474&s=gateway&sr=8-7

You'd want this one:
https://www.amazon.com/BV-Tech-Switch-Gigabit-Ethernet-uplink/dp/B01MQHD54L/ref=sr_1_3?keywords=bv+tech&qid=1559295508&s=gateway&sr=8-3

I've heard good things about the ipcampower ones:
https://www.amazon.com/dp/B07BW8FNVW/ref=sspa_dk_detail_0?pd_rd_i=B076HWG8F3&pd_rd_w=WLbrp&pf_rd_p=8a8f3917-7900-4ce8-ad90-adf0d53c0985&pd_rd_wg=ISg1A&pf_rd_r=EC3B22YQ3SYFDGXK6MGS&pd_rd_r=0be15b25-8388-11e9-a9ce-814cf5dd9e62&th=1

All of these are unmanaged.

Channels indicate the number of cameras it will support in total.

For these HikVision NVRs with the built-in PoE (Power over Ethernet) ports, if you are using HikVision cameras they will be plug and play (One camera plugged into one port) it will automatically find the cam, give it an IP, and pull the video streams back to the NVR.

For the 16ch (DS-7716NI-I4/P16) it will allow you to do this for all the channels (Channels 1-16). For the 32ch Model (DS-7732NI-I4/P16P) it is unable to pull enough power for the NVR, HDDs, and 32 cameras, so this model only has 16 ports of PoE on the back. This will allow you to plug and play channels 1-16, just like on the 16ch model.

For channels 17-32 they will not be plug and play. You will need to get and separate 16 port PoE switch like this or a couple smaller switches connected to the same router to be able to pull the video for those cameras through the local network. You will need to run the HikVision search tool SADP to find these cameras, manually give them IP addresses, then you can go into the camera configuration on the NVR to tell it which channel is which IP address.