04-05-2014, 03:36 PM
Yes, there is a system in place for that.. the CMTS tells the cable modem when it can talk upstraem, and how much it can talk at a time upstream, if it tries to talk more than its allowed, the CMTS will boot it off the network, same for downstream, the CMTS will only send data as fast as the QoS classifier the modem is registered with.