How to set up access to the DVR on 2 Internet?

Question

Computer networks

There are 2 DVRs and 2 Internet, 4 cameras go to these DVRs. That is, they receive the same signal from 4 identical cameras, both of them.
As I understand it, this is done in order to duplicate the connection to the Internet.
There is internet via cellular, there is internet via satellite.
1 DVR is now configured via cellular. 2nd does not have a cloud service for viewing, so they are going to buy a white IP and go to it.
Now the crux of the problem. Is it possible to configure the network so that. The router, in case of poor cellular communication, provided Internet from the satellite. Or vice versa.
Of the equipment there are 2 zixel routers.
One sane person successfully hangs a registrar on it and the settings are quite conveniently written there. The second with quirks. From Internet sharing settings: I can build routing tables. However, when the router's network is 192.168.1.0 I redirect to 0.0.0.0 which is redirected to 10.168.0.1 (internet). Nothing connects to the Internet. ping 8.8.8.8 is also not successful. The problem is not DNS.
Maybe I can use this router as a node that will have routing tables for 2 internets?
Before that, I had only experience in setting up web servers. Kick, please, in the right direction.

Answer 1

Your problems are worth $80. market.yandex.ru/model.xml?modelid=5053597&hid=723087 here is a router with balancing, on the stock firmware it can switch from 3G \ 4G to the wire and back in case of a channel drop.

Answer 2

or maybe you need to deal with a fancy zuhel, update the firmware, forward the video recorder (usually NAT-VirualServer).

Answer 3

Cheap MikroTik rb951g-2hnd or rb751u-2hnd or rb751g-2hnd. And with the right setup, all your problems will be solved.