Media Bandwidth Management; Chapter 20 Media Bandwidth Management; Bandwidth Management Overview; Bandwidth Classes And Filters - ZyXEL Communications Prestige 662HW Series User Manual

This chapter describes the functions and configuration of bandwidth management.

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 screen (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 screen (see section 20.9 for details).
The total of the configured bandwidth budgets for child-classes cannot exceed the configured
bandwidth budget speed of the parent class.

20.3 Proportional Bandwidth Allocation

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.

Media Bandwidth Management

Media Bandwidth Management
Prestige 662HW Series User's Guide
Chapter 20
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