What software / service for broadcasting 15-20 remote webcams to the office can be used for free?

Question

Video broadcast

1) There are 12 points around the city, each point has a laptop with a webcam
1.a) The number of points will increase to about 20
2) There is an office where you need to broadcast video and sound
2.a) Automatic dialing is desirable when turned on (and after a connection break) systems
We need a cross-platform (win7,8,10/debian) software or service that will allow you to do this for free and automatically.

current absurdity

В данный момент в офисе абсурд какой-то: 12 ноутбуков с запущенными скайпами, на каждый из которых дозванивается каждая точка персонально. Ноуты в офисе автоматически принимают звонки от "своей" точки. Звук по дефолту заглушен на всех ноутах и включается вручную по надобности. Так и живут.
Хочу повесить трансляции на один ноут, с которого вывести изображения на ТВ на стене.

Answer 1

Unfortunately, there is hardly a ready-made solution for your needs.
I suggest running ffmpeg/vlc on each laptop, which captures a picture from the device, presses it with the necessary codec and publishes it to the network, opening a port on the machine for broadcasting via http/rtmp. The problem is only in providing connectivity: either port forwarding and the presence of an external IP, or full connectivity through a VPN.
In this case, the consumer(s) know the IP and port of the device on which the stream is being broadcast. Watch again with any vlc/ffmpeg.
In the best case, we raise multicast, then there can be as many viewers as you like, the bandwidth will be occupied by only one stream on each laptop.

Answer 2

There are different options, if you are a free employee (read the owner), then you can mess with this or this one (the same garbage, view from the wrapper on the node).
If you have something to do at work, then specialized solutions for security and not very video surveillance of a wagon and a trolley.
From multifunctional combines in the face of vovza and fluxonics , to special solutions in the face of a macroscope, tracer, etc.

Answer 3

https://ru.ivideon.com/tarify-dlya-doma/
Connect up to 15 cameras on home tariffs!