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to a Class of Service value by the switch, and the traffic then sent to the
corresponding output queue.
If the QoS mode is set to 802.1p, and the ingress packet type is IPv4, then
priority processing will be based on the 802.1p value in the ingress packet.
For an untagged packet, the default port priority is used for priority
processing (i.e., CoS value 0, which maps to the Normal Queue).
If the QoS mode is set to DSCP, and the ingress packet type is IPv4, then
priority processing will be based on the DSCP value in the ingress packet.
Field Attributes
Queue Mode
• Strict - Services the egress queues in sequential order, transmitting all
traffic in the higher priority queues before servicing lower priority
queues.
• WRR – Weighted Round-Robin shares bandwidth at the egress ports by
using scheduling weights with default values of 1, 2, 4, 8 for queues 0
through 7, respectively. (This is the default selection.)
Note that WRR can only be selected if Jumbo Frame mode is disabled
on the Port Configuration page (see “Port Configuration” on page 6-24).
QoS Mode
• QoS Disabled – QoS is turned off and all packets have equal priority.
• 802.1p – Packets are prioritized using the 802.1p field in the VLAN tag.
This field is three bits long, representing the values 0 - 7. When the QoS
Mode is set to 802.1p, the 802.1p Configuration table appears, allowing
you to map each of the eight 802.1p values to a local priority queue (low,
normal, medium or high). The default settings are shown below.
You can use the Prioritize Traffic drop-down list to quickly map the
values in the 802.1p Configuration table to the same priority queue. Use
Mapping CoS Values to Egress Queues
Egress Queue low normal medium high
802.1-p Priority 1,2 0,3 4,5 6,7
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