ZyXEL Communications 650 Series - Manual (Page 227)

Prestige 650 Series User’s Guide
Bandwidth Management 20-1
Chapter 20
Bandwidth Management
This chapter describes the functions and configuration of bandwidth management. This chapter
only applies to the Prestige P650H/HW.
20.1 Bandwidth Management Overview
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.
20.2 Bandwidth Classes and Filters
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 20.9.1) 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 20.9 for details).