ZyXEL p-660h-61 用户指南

Prestige 660H Series User’s Guide  

Bandwidth Management 

       18-1 

Bandwidth management allows you to allocate an interface’s outgoing capacity to specific types of 
traffic. It can also help you make sure that the Prestige forwards certain types of traffic (especially 
real-time applications) with minimum delay. With the use of real-time applications such as Voice-
over-IP (VoIP) increasing, the requirement for bandwidth allocation is also increasing.  

Bandwidth management addresses questions such as: 

♦  Who gets how much access to specific applications? 
♦  What priority level should you give to each type of traffic? 
♦  Which traffic must have guaranteed delivery? 
♦  How much bandwidth should be allotted to guarantee delivery? 

Bandwidth management also allows you to configure the allowed output for an interface to match 
what the network can handle. This helps reduce delays and dropped packets at the next routing device. 
For example, you can set the WAN interface speed to 1000kbps if the ADSL connection has an 
upstream speed of 1000kbps. All configuration screens display measurements in kbps (kilobits per 
second), but this User’s Guide also uses Mbps (megabits per second) for brevity’s sake. 

Use bandwidth classes and child-classes to allocate specific amounts of bandwidth capacity 
(bandwidth budgets). Configure a bandwidth filter to define a bandwidth class (or child-class) based 
on a specific application and/or subnet. Use the Class Configuration tab (see section 18.9.1) to set up 
a bandwidth class’s name, bandwidth allotment, and bandwidth filter. You can configure up to one 
bandwidth filter per bandwidth class. You can also configure bandwidth classes without bandwidth 
filters. However, it is recommended that you configure child-classes with filters for any classes that 
you configure without filters. The Prestige leaves the bandwidth budget allocated and unused for a 
class that does not have a filter itself or child-classes with filters. View your configured bandwidth 
classes and child-classes in the Class Setup tab (see section 18.9 for details). 

The total of the configured bandwidth budgets for child-classes cannot exceed the configured 
bandwidth budget speed of the parent class.  

Bandwidth management allows you to define how much bandwidth each class gets; however, the 
actual bandwidth allotted to each class decreases or increases in proportion to actual available 
bandwidth.