ZyXEL Communications ZyXEL ZyWALL 35 - Manual (Page 328)

ZyWALL 35 User’s Guide
326 Chapter 19 Bandwidth Management
Figure 160 Maximize Bandwidth Usage Example
19.7 Bandwidth Borrowing
Bandwidth borrowing allows a sub-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 sub-class to allow the sub-class to use its parent class’s
unused bandwidth. A parent class’s unused bandwidth is given to the highest priority sub-class
first. The sub-class can also borrow bandwidth from a higher parent class (grandparent class)
if the sub-class’s parent class is also configured to borrow bandwidth from its parent class.
This can go on for as many levels as are configured to borrow bandwidth from their parent
class (
see the Bandwidth Borrowing Example section ).
The total of the bandwidth allotments for sub-classes cannot exceed the bandwidth allotment
of their parent class. The ZyWALL uses the scheduler to divide a parent class’s unused
bandwidth among the sub-classes.
19.7.1 Bandwidth Borrowing Example
Here is an example of bandwidth management with classes configured for bandwidth
borrowing. The classes are set up based on departments and individuals within certain
departments.