P-660H/HW/W-T Series User’ Guide

Figure 91 Maximize Bandwidth Usage Example

16.7 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.

Enable bandwidth borrowing on a child-class to allow the child-class to use its parent class’s unused bandwidth. A parent class’s unused bandwidth is given to the highest-priority child- class that has bandwidth borrowing configured, first.

The total of the bandwidth allotments for child-classes cannot exceed the bandwidth allotment of their parent class. The Prestige uses the scheduler to divide a parent class’s unused bandwidth among the child-classes.

16.7.1 Maximize Bandwidth Usage With Bandwidth Borrowing

If you configure both maximize bandwidth usage (on the interface) and bandwidth borrowing (on individual child-classes), the Prestige functions as follows.

1The Prestige sends traffic according to each bandwidth class’s bandwidth budget.

2The Prestige assigns a parent class’s unused bandwidth to its child-classes that have more traffic than their budgets and have bandwidth borrowing enabled. The Prestige gives priority to bandwidth child-classes of higher priority and treats bandwidth classes of the same priority equally.

3The Prestige assigns any remaining unused or unbudgeted bandwidth on the interface to any bandwidth class that requires it. The Prestige gives priority to bandwidth classes of higher priority and treats bandwidth classes of the same level equally.

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Chapter 16 Media Bandwidth Management Advanced Setup