How to know the machine doing all that traffic ???

Using winbox, how can I detect a machine on the Lan that is producing a lot of internet traffic thus saturating DSL band ??
Thank you

In Winbox, you can look at IP → Firewall → Connections.
Turn on the “Orig./Repl. Rate” and “Orig./Repl.Bytes” columns.
Those will show you the source address, rate and amount transferred.

You can also use the Torch tool to help diagnose it.