ZyXEL p-660h-61 Guida Utente

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Prestige 660H Series User’s Guide  
Bandwidth Management 
       18-3 
 
Table 18-4 Application and Subnet-based Bandwidth Management Example 
18.5 Scheduler 
The scheduler divides up an interface’s bandwidth among the bandwidth classes. The Prestige has two 
types of scheduler: fairness-based and priority-based.  
18.5.1 Priority-based Scheduler 
With the priority-based scheduler, the Prestige 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. 
18.5.2 Fairness-based Scheduler 
The Prestige 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.  
18.6  Maximize Bandwidth Usage 
The maximize bandwidth usage option (see Table 18-8) allows the Prestige 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 Prestige first makes sure that each bandwidth class 
gets up to its bandwidth allotment. Next, the Prestige 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 Prestige gives extra bandwidth to that class.  
When multiple classes require more bandwidth, the Prestige 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 Prestige distributes the available 
bandwidth equally among classes with the same priority level.  
18.6.1 Reserving Bandwidth for Non-Bandwidth Class Traffic 
Do the following three steps to configure the Prestige to allow bandwidth for traffic that is not defined 
in a bandwidth filter.