ZyXEL Communications ZyXEL ZyAIR 100 - Manual (Page 272)

ZyWALL 10~100 Series Internet Security Gateway
18-8 Bandwidth Management Screens
18.7 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 first. The child-
class can also borrow bandwidth from a higher parent class (grandparent class) if the child-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 section 18.7.1).
The total of the bandwidth allotments for child-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 child-
classes.
18.7.1 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.