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to ensure that each queue obtains a certain service time. WRR
configures a weighted value (w3, w2, w1 and w0) for each
queue. The weighted value represents the proportion of the
obtained resources. For example, the weighted value of WRR
queue schedule algorithm of a 100M port is configured as 50,
30, 10 and 10 (corresponding to w3, w2, w1 and w0), so that
the queue with minimum priority obtains a bandwidth of at least
10Mbps, which avoids the disadvantage that a message in
queue with low priority during PQ schedule may not obtain
service for a long time. WRR queue still has another advantage.
Although the schedule of these queues are conducted in turn,
each queue is not assigned with a fixed service time slice-if a
certain queue is null, it is immediately changed to the next
queue. In this way, the bandwidth resources can be fully
utilized.
4.4.5.3 QoS-QoS Classification
Some applications require specific bandwidth to ensure its data
be forwarded in time. QoS classification can creates traffic
class rule to classify the upstream traffic. Assign queue which
defines the precedence and the interface and optionally
overwrite the IP header DSCP byte. After QoS classification,
QoS divides capacity between different applications and
provides undelayed, continuous data transfer where data
packet with higher priority is given preference. The follow figure
shows QoS classification.
