P-661H/HW Series User’s Guide

•Research requires more bandwidth but only gets its budgeted 2048 kbps because all of the unbudgeted and unused bandwidth goes to the higher priority sales and marketing classes.

15.6.2.2Fairness-based Allotment of Unused and Unbudgeted Bandwidth

The following table shows the amount of bandwidth that each class gets.

Table 96 Fairness-based Allotment of Unused and Unbudgeted Bandwidth Example

BANDWIDTH CLASSES AND ALLOTMENTS

Root Class: 10240 kbps

Administration: 1024 kbps

 

 

 

Sales: 3072 kbps

 

 

 

Marketing: 3072 kbps

 

 

 

Research: 3072 kbps

 

 

Suppose that all of the classes except for the administration class need more bandwidth.

•Each class gets up to its budgeted bandwidth. The administration class only uses 1024 kbps of its budgeted 2048 kbps.

•The ZyXEL Device divides the total 3072 kbps total of unbudgeted and unused bandwidth equally among the other classes. 1024 kbps extra goes to each so the other classes each get a total of 3072 kbps.

15.6.3Over Allotment of Bandwidth

You can 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 97 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

High

as Speed setting)

 

 

NetMeeting traffic (Service = H.323): 500 kbps

High

 

 

 

 

 

FTP (Service = FTP): 500 Kbps

Medium

 

 

 

If you use VoIP and NetMeeting at the same time, the device allocates up to 500 Kbps of bandwidth to each of them before it allocates any bandwidth to FTP. As a result, FTP can only use bandwidth when VoIP and NetMeeting do not use all of their allocated bandwidth.

Suppose you try to browse the web too. In this case, VoIP, NetMeeting and FTP all have higher priority, so they get to use the bandwidth first. You can only browse the web when VoIP, NetMeeting, and FTP do not use all 1000 Kbps of available bandwidth.

Chapter 15 Bandwidth Management

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