ZyXEL Communications ZyXEL ZyWALL 35 - Manual (Page 329)

ZyWALL 35 User’s Guide
Chapter 19 Bandwidth Management 327
Figure 161 Bandwidth Borrowing Example
• The Sales USA class can borrow unused bandwidth from the Sales class because the
Sales USA class has bandwidth borrowing enabled.
• The Sales USA class cannot borrow unused bandwidth from the Root class because the
Sales class has bandwidth borrowing disabled.
• The Sales Asia class cannot borrow unused bandwidth from the Sales class because the
Sales Asia class has bandwidth borrowing disabled.
• The R&D Software and Hardware classes can both borrow unused bandwidth from the
R&D class because the R&D Software and Hardware classes both have bandwidth
borrowing enabled.
• The R&D Software and Hardware classes can also borrow unused bandwidth from the
Root class because the R&D class also has bandwidth borrowing enabled.
19.7.2 Maximize Bandwidth Usage With Bandwidth Borrowing
If you configure both maximize bandwidth usage (on the interface) and bandwidth borrowing
(on individual sub-classes), the ZyWALL functions as follows.
1 The ZyWALL sends traffic according to each bandwidth class’s bandwidth budget.
2 The ZyWALL assigns a parent class’s unused bandwidth to its sub-classes that have more
traffic than their budgets and have bandwidth borrowing enabled. The ZyWALL gives
priority to bandwidth sub-classes of higher priority and treats bandwidth classes of the
same priority equally.