ZyXEL Communications 2 Plus 19.9Maximize Bandwidth Usage With Bandwidth Borrowing, 19.10Over Allotment of Bandwidth

Chapter 19 Bandwidth Management

Refer to the product specifications in the appendix to see how many class levels you can configure on your ZyWALL.

Table 106 Bandwidth Borrowing Example

BANDWIDTH CLASSES AND BANDWIDTH BORROWING SETTINGS

Root Class:	Administration: Borrowing Enabled

	Sales: Borrowing Disabled

	Marketing: Borrowing Enabled

	Research: Borrowing Enabled

•The Administration class can borrow unused bandwidth from the Root class because the Administration class has bandwidth borrowing enabled.

•The Sales class cannot borrow unused bandwidth from the Root class because the Sales class has bandwidth borrowing disabled.

19.9Maximize 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.

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

2The 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 sub-classes of higher priority and treats classes of the same priority equally.

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

4If the bandwidth requirements of all of the traffic classes are met and there is still some unbudgeted bandwidth, the ZyWALL assigns it to traffic that does not match any of the classes.

19.10Over Allotment of Bandwidth

It is possible to set the bandwidth management speed for an interface higher than the interface’s actual transmission speed. Higher priority traffic gets to use up to its allocated bandwidth, even if it takes up all of the interface’s available bandwidth. This could stop lower priority traffic from being sent. The following is an example.

Table 107 Over Allotment of Bandwidth Example

BANDWIDTH CLASSES, ALLOTMENTS		PRIORITIES
Actual outgoing bandwidth available on the interface: 1000 kbps

Root Class: 1500 kbps (same	VoIP traffic (Service = SIP): 500 Kbps	7
as Speed setting)
as Speed setting)	NetMeeting traffic (Service = H.323): 500 kbps	7
	NetMeeting traffic (Service = H.323): 500 kbps	7

	FTP (Service = FTP): 500 Kbps	3

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