How to track what clogs the channel?

Question

Computer networks

The problem is the following, about 30-40 computers are constantly downloading something from the file server and this greatly clogs the channel, the problem persists even at night when no one is working on the computers. The software is standard everywhere, I did not see any tasks in the schedulers.
Everything that the system process could find on port 445 is constantly pumping out, but I can’t understand why this is happening, I broke my whole head.
There are no administrator rights on the server, I don’t know if this will really help in the analysis or not. I tried to watch through Wireshark, but the knowledge is not enough to understand all the information.

Answer 1

Novel What computers are known, even the process is known (I wrote above). It is not clear why computers pump out something constantly, even when a person does not work at a computer.
Upd: In general, the whole thing turned out to be that critical updates were not installed on Kaspersky, where this bug was fixed.

Answer 2

Ask the server administrator for statistics from which IP addresses the channel is loaded and who consumes how much traffic and it will be clear to you which or which PCs are doing this. Well, or it turns out that your channel is simply too small for 40 computers.

Answer 3

In my opinion, you yourself have answered your question. Since this is a file server, try to see which folders are open and by whom. You know that traffic is coming to x PCs, start closing connections until you close what is consuming.