3Com CoreBuilder 3500, Implementation Manual, Page: 481 / 592

Key Concepts 481
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Timer option — The QoS Timer option lets you configure a QoS
session to take effect during a predefined time period by setting
the start and end times for the specific control.
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IEEE 802.1Q priority tag — When you define a control for a
classifier, you can select an IEEE 802.1p priority tag value to insert
into forwarded frames. Make sure that this priority tag is applied to
ports that are configured for IEEE 802.1Q tagging.
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QoS bandwidth — Specifies the weighting of the high priority and
best effort transmit queues. The bandwidth for the control queue is
set via RSVP. By default, 75 percent of the bandwidth is used for high
priority traffic and 25 percent is used for best effort packets (that is,
three high priority packets are sent for each best effort packet). Low
priority packets do not have bandwidth allocated.
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QoS excess tagging
— Enables you to select an IEEE 802.1p priority
tag value for nonconforming excess packets (packets that exceed the
rate limit). This option refers to any packets marked as excess that you
want to tag. If you enable this option, you can select an IEEE 802.1p
priority tag value in the range of from
0 to 7 , with 0 as the default.
Specifying 1 means that nonconforming excess become background
traffic. (See Table 59 earlier in this chapter.)