How to organize video surveillance with a remote server?

Question

CCTV

There are 4 objects. The task is to make it so that four objects record motion from ip-cameras to a remote server + remote access from the phone
First object: 1 camera. Located at a distance from the server - 1km
Second object: 2 cameras. Located at a distance from the server - 2 km
Third object: 3 cameras. Located at a distance from the server - 4 km
The fourth object: 4 cameras. It is located at a distance from the server - 60 km
As far as I understand, the scheme is as follows: the ip-camera is connected to the router, the router to the DVR, the DVR sends data to the server.
Please explain how such a system can be implemented. I understand that it takes a long time to paint everything, but at least tell me where to dig

Answer 1

DVR sends data to the server

No, DVR ~= server.
Usually either one or the other. A DVR is a cheaper solution. The server is installed when there are a lot of cameras (more than 16), or you need to store records for a long time (a year), or you need to recognize faces, numbers, etc., or some other special requirements. In simple cases, a registrar is enough (essentially the same server, only low-power, cheap, easily customizable).
There are two opposing strategies.
(1) What if the facility loses Internet access? We'll be left with no records. No, that's not good enough! We install recorders locally at each facility, in the guard room (plus a monitor at the guard for viewing), so that recording is always done locally. We are only viewing from a distance. If there is no connection, then we can look at the records later, or we will come to the facility and look there.
(2) There is no guard at the facility. But what if an attacker at the facility gets to the registrar and destroys all the records? No, that's not good enough! We install the registrars remotely, in a secure room, the records will be safe. Communication rarely disappears, and if it does, we will quickly go to the object and sort it out (even at night).
Can be combined:
(3) We have a lot of money (but there is still no security at the facilities), so we will buy more equipment, let the recording be done both locally at the facilities and remotely.

Answer 2

Yes, registrar-replacement server (for a beginner - the best option).
I would put rvi / dahua and Internet iota / mts / etc. on each object.
If there are concerns like "they will steal the registrar from the object" - then each object needs Internet connections with static IPs (corporate rates of the same iota / mts), forward ports to the cameras on the routers and configure the "central" registrar to these ip and ports. This does not exclude the previous option, it is possible together.
If the Internet cannot be organized in any way (they do not catch iota / mts / etc.) - up to 4 km, you can probably make wi-fi bridges, for this you will need to hang something from ubiquiti at a height and find a specialist working with it.
Rvi/dahua advised because their smartpss and dmss work well even if the internet is without a static ip. For the second and third options hiwatch is no worse