User`s guide

Chapter 18 Bandwidth Management Screens
LAN-Cell 2 User’s Guide
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18.1.3.2 Maximize Bandwidth Usage Example
If you configure both maximize bandwidth usage (on the interface) and bandwidth borrowing
(on individual sub-classes), the LAN-Cell functions as follows.
1 The LAN-Cell sends traffic according to each bandwidth class’s bandwidth budget.
2 The LAN-Cell assigns a parent class’s unused bandwidth to its sub-classes that have
more traffic than their budgets and have bandwidth borrowing enabled. The LAN-Cell
gives priority to sub-classes of higher priority and treats classes of the same priority
equally.
3 The LAN-Cell assigns any remaining unused or unbudgeted bandwidth on the interface
to any class that requires it. The LAN-Cell gives priority to classes of higher priority and
treats classes of the same level equally.
4 If the bandwidth requirements of all of the traffic classes are met and there is still some
unbudgeted bandwidth, the LAN-Cell assigns it to traffic that does not match any of the
classes.
18.1.3.3 Over Allotment of Bandwidth Example
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.
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.
Table 132 Over Allotment of Bandwidth Example
BANDWIDTH CLASSES, ALLOTMENTS PRIORITIES
Actual outgoing bandwidth available on the interface: 1000 kbps
Root Class: 1500 kbps (same
as Speed setting)
VoIP traffic (Service = SIP): 500 Kbps 7
NetMeeting traffic (Service = H.323): 500 kbps 7
FTP (Service = FTP): 500 Kbps 3