Extreme Networks ExtremeWare XOS 11.3, Manual

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QoS Profiles
ExtremeWare XOS 11.3 Concepts Guide
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DiffServ
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dot1p
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VLAN-based QoS
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Port-based QoS
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You may receive an error message when configuring a QoS feature in the above list on the
BlackDiamond 8800 family of switches and the Summit X450 switch; it is possible that the shared
resource is depleted. In this case, unconfigure one of the other QoS features and reconfigure the one
you are working on.
The next sections describe each of these QoS components in detail.
QoS Profiles
QoS profiles are configured differently:
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On the BlackDiamond 8800 family of switches and the Summit X450 switch
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On the BlackDiamond 10K switch.
QoS Profiles on the BlackDiamond 8800 Family of Switches and
the Summit X450 Switch Only
The BlackDiamond 8800 family of switches and the Summit X450 switch have two default queues, QP1
and QP8, which are based on traffic flows. QP1 has the lowest priority, and QP8 has the highest priority.
You can configure up to six additional QoS profiles, or queues, on the switch, QP2 through QP7.
Creating a queue dynamically will not cause loss of traffic. You can also modify the default parameters
of each QoS profile. The names of the QoS profiles, QP1 through QP8, are not configurable.
The parameters that make up a QoS profile on the BlackDiamond 8800 family of switches and the
Summit X450 switch include:
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Buffer—This parameter is the maximum amount of packet buffer memory available to all packets
associated with the configured QoS profile within all affected ports. All QoS profiles use 100% of
available packet buffer memory by default. You can configure the buffer amount from 1 to 100%, in
whole integers. Regardless of the maximum buffer setting, the system does not drop any packets if
any packet buffer memory remains to hold the packet and the current QoS profile buffer use is
below the maximum setting.
NOTE
Use of all 8 queues on all ports may result in insufficient buffering to sustain 0 packet loss throughput during
full-mesh connectivity with large packets.
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Weight—This parameter is the relative weighting for each QoS profile; 1 through 16 are the available
weight values. The default value for each QoS profile is 1, giving each queue equal weighting. When
you configure a QoS profile with a weight of 4, that queue is serviced 4 times as frequently as a
queue with a weight of 1. However, if you configure all QoS profiles with a weight of 16, each queue
is serviced equally but for a longer period of time.
Finally, you configure the scheduling method that the entire switch will use to empty the queues. The
scheduling applies globally to the entire switch, not to each port. You can configure the scheduling to be