Installation and Getting Started Guide
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Layer 2 port-based VLAN membership
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802.1q tag
NOTE: QoS is supported only on the HP 9304M, HP 9308M, and HP 6308M-SX. On the HP HP 6208M-SX, you
can assign certain types of traffic to the high queue instead of the normal queue, but the other features described
in this chapter are not supported.
IP Type of Service (TOS) Mapping
HP devices that support QoS automatically place incoming IP packets into one of the four priority queues based
on the value of the first two bits in the Type of Service (TOS) field. Thus, if the TOS field contains a value
equivalent to the highest priority, the packet is placed into the premium queue (highest priority queue) and given
premium service throughout the device.
Selectable Queuing Method
QoS allows you to select one of the following queueing methods:
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Strict – Higher level queues are preferred over lower level queues
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Bandwidth – A weighted fair queuing algorithm is used to rotate service among the four queues. The number
of packets in each queue that are serviced during a single rotation is based on the weights the software
assigns to the queues. The weights are based on the bandwidth percentages you allocate to each of the
queues.
Configurable Bandwidth Percentages
For weighted fair queuing, you can specify the minimum percentages of bandwidth each queue should receive.
The device applies a weight to each queue based on normalized values for the percentages you enter.
802.1q Priority Mapping
By default, devices with QoS assign 802.1q tagged VLAN packets into one of the four QoS queues based on the
prioritization value in the tag field. You can bias tagged traffic to lower or higher queues by remapping the
prioritization values.
Queue Assignment by Traffic Type
You can assign the following traffic types to one of the four QoS queues:
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IP source and destination addresses
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Layer 4 source and destination information (for all IP addresses or specific IP addresses)
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Static MAC entry
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AppleTalk socket number
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Layer 2 port-based VLAN membership
NOTE: This part of QoS was supported in earlier software releases too, but always used the default queue
weights.
In addition, QoS allows you to assign packets to a QoS queue based on the incoming (ingress) port.
Layer 2 Switching Features
The following sections describe the switching features listed in Table 7.1 on page 7-1.
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