How does the mobile operator understand in what capacity I watch the video?

Question

Computer networks

I saw an interesting sub-item in the description of the "unlimited" tariff plan:

When watching video online, the maximum quality is not limited for the first 3 months from the moment of connection to the tariff plan, then the maximum available video quality is 480p format.

Actually, how can the operator understand in what capacity I am watching the video?

Answer 1

In the network of any mobile operator there is a PCEF node that determines the types of user traffic. This is how, for example, instant messengers, social networks, videos, etc. are separated. The quality of the video stream can be unambiguously determined based on the amount of information transmitted. Further, after the trial period has expired, you can limit the speed to a specific service, the video quality will be automatically adjusted (using the same HLS protocol) to the available bandwidth.

Answer 2

Well, depending on where ... but on all the norms of video services there are different "streams" for different video resolutions ... so that it can be seen Is
n't it easier to immediately connect the operator's norms?

Answer 3

If we are not talking about some kind of operator’s own service, then the only thing that comes to mind is limiting the bandwidth of individual connections (but this is about a finger in the sky, since, of course, there is no single and exact figure corresponding to 480p exist).
It is impossible for the operator to know for sure that you are watching the video on the site, and not, say, downloading a file or playing an online game.

Answer 4

Perhaps, according to the amount of information transmitted per unit of time, it approximately determines, but only the bit rate can be determined in this way. And so, the higher the quality, the higher the bitrate, but it is impossible to determine one from the other, one can only roughly assume based on some statistics. For example, collect a thousand video files with 480p, measure their average bitrate and dance from this figure.
Perhaps the provider does something like this - it cuts the speed to such that average videos at 480p are somehow played without delays, and at 720p with delays.

Answer 5

The provider may not bother at all and simply cut the speed of access to YouTube.