ZyXEL Communications 10 - Manual (Page 317)

ZyWALL 10~100 Series Internet Security Gateway
Bandwidth Management 25-1
Chapter 25
Bandwidth Management
This chapter describes the functions and configuration of bandwidth management. Bandwidth
management applies to the ZyWALL 100.
25.1 Introduction
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 ZyWALL 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 broadband device connected to the WAN port 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.
25.2 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