ZyXEL Communications P-660W-T1 v2, User Manual

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P-660W-Tx v2 User’s Guide
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H A P T E R
16
Media Bandwidth Management
Advanced Setup
16.1 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 ZyXEL Device 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 1Mbps. 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.
16.2 What You Need to Know About Media Bandwidth
Management
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.
Bandwidth Borrowing
Bandwidth borrowing allows a child-class to borrow unused bandwidth from its parent class,
whereas maximize bandwidth usage allows bandwidth classes to borrow any unused or
unbudgeted bandwidth on the whole interface.