Every 15 minutes, a system verifies the traffic rate of each upstream channel (typically, one upstream channel serves a few dozen modems). If the traffic rate exceeds the threshold above which congestion occurs, the system identifies the modems that are uploading a large amount of data. The upload capacity of these modems is then given a low-priority rating. However, if the congestion persists or increases, then the upload speed of these modems may slow down.
When the amount of data uploaded by the modem is diminished or the traffic on that channel reverts to a normal enough rate that congestion is no longer an issue, the upload capacity will go back to its usual priority. Even when they are no longer prioritized, modems for 30 Mbit/s upload speed plans can use up all the upload bandwidth that other modems are not using, at a speed equivalent to these modems’ nominal speed.
The measures described above are implemented on an ongoing basis.