Scheduler; Maximize Bandwidth Usage; Figure 17-3 Application And Subnet-Based Bandwidth Management Example - ZyXEL Communications ZyWALL 5 User Manual

ZyWALL 5 Internet Security Appliance

Figure 17-3 Application and Subnet-based Bandwidth Management Example

17.5 Scheduler

The scheduler divides up an interface's bandwidth among the bandwidth classes. The ZyWALL has
two types of scheduler: fairness-based and priority-based.
17.5.1 Priority-based Scheduler
With the priority-based scheduler, the ZyWALL forwards traffic from bandwidth classes according to
the priorities that you assign to the bandwidth classes. The larger a bandwidth class's priority number
is, the higher the priority. Assign real-time applications (like those using audio or video) a higher
priority number to provide smoother operation.
17.5.2 Fairness-based Scheduler
The ZyWALL divides bandwidth equally among bandwidth classes when using the fairness-based
scheduler; thus preventing one bandwidth class from using all of the interface's bandwidth.

17.6 Maximize Bandwidth Usage

The maximize bandwidth usage option (see Figure 17-7) allows the ZyWALL to divide up any
available bandwidth on the interface (including unallocated bandwidth and any allocated bandwidth
that a class is not using) among the bandwidth classes that require more bandwidth.
When you enable maximize bandwidth usage, the ZyWALL first makes sure that each bandwidth
class gets up to its bandwidth allotment. Next, the ZyWALL divides up an interface's available
bandwidth (bandwidth that is unbudgeted or unused by the classes) depending on how many
bandwidth classes require more bandwidth and on their priority levels. When only one class requires
more bandwidth, the ZyWALL gives extra bandwidth to that class.
When multiple classes require more bandwidth, the ZyWALL gives the highest priority classes the
available bandwidth first (as much as they require, if there is enough available bandwidth), and then to
lower priority classes if there is still bandwidth available. The ZyWALL distributes the available
bandwidth equally among classes with the same priority level.
Bandwidth Management 17-3