This scheme gives the benefits of SmoothTraffic without enforcing fairness (situations exist where fairness may not be appropriate). In the "Default" scheme the guaranteed bandwidth for high priority traffic is limited. This is a valid trade-off - there has to be a limit to high priority use or lower priority traffic gets too little bandwidth.

In a situation where there are only one or two users of the network connection then those users can do without the fairness of the Default scheme. This scheme differs from Default in that the high_priority class is guaranteed at least 88% of the bandwidth. This means that if there is enough high priority traffic it will get most of the bandwidth. There are then three levels of normal_priority traffic. If, once high_priority traffic has been satisfied, there is any spare bandwidth then normal_priority1 traffic will get first chance to use it followed by normal_priority2 and finally normal_priority3. Unused bandwidth 'cascades' down to lower priority classes - hence the name of the scheme.

Note that the guaranteed bandwidths for these tags are just 1% so they not should be used for performance critical traffic.

low_priority is limited to 60% of available bandwidth and slow to just 10% of bandwidth - these limits are set even if the line has available capacity.

In summary: using the Cascade scheme will let you enjoy the maximum bandwidth of a personal Internet connection for streaming media/games etc. and be able to have non speed critical background tasks such as downloading email going on at the same time with no disruption. The lack of fairness makes it unsuitable for situations where many users are sharing the same connection.