How does an AR send packets with high DSCP value to high-priority queues?

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In a traffic classifier, configure the AR to send packets with the high DSCP value to EF queues so that the packets are preferentially processed.
For example, configure the AR to send packets with the DSCP value of 22 to EF queues.
[Huawei] traffic classifier c1
[Huawei-classifier-c1] if-match dscp 22
[Huawei-classifier-c1] quit
[Huawei] traffic behavior b1
[Huawei-behavior-b1] queue ef bandwidth 100 cbs 2500
[Huawei-behavior-b1] quit
[Huawei] traffic policy p1
[Huawei-trafficpolicy-p1] classifier c1 behavior b1

Other related questions:
How does an AR send packets with a specific DSCP to high-priority queues

Use traffic classifiers to enable packets with high differentiated services code point (DSCP) values to enter expedited forwarding (EF) queues, and to ensure that the packets are transmitted preferentially. For example, to enable packets with a DSCP of 22 to enter EF queues, configure the following:

[Huawei] traffic classifier c1 [Huawei-classifier-c1] if-match dscp 22 [Huawei-classifier-c1] quit [Huawei] traffic behavior b1 [Huawei-behavior-b1] queue ef bandwidth 100 cbs 2500 [Huawei-behavior-b1] quit [Huawei] traffic policy p1 [Huawei-trafficpolicy-p1] classifier c1 behavior b1

Mapping between differentiated services code point (DSCP) and local priority
IP packets carry the DSCP field to indicate the QoS preference. The mapping between the priority fields must be configured on the gateway to retain packet priorities when the packets traverse different networks. You can run the display qos map-table command to view the mapping between priorities, or run the input command in the priority mapping table view to configure the mapping between priorities.

Question about packet loss when the rate of ping packets is high on S series switches
When another device pings an S series switch (a non-S1700 switch), the device and the switch exchange ICMP packets. To protect the CPU, you can run the icmp rate-limit command to configure a rate threshold for ICMP packets. The undo icmp rate-limit command restores the default rate threshold of ICMP packets.

Method used to configure congestion avoidance and congestion management on S series switches
For S series switches (except the S1700), congestion avoidance prevents a network from being overloaded using a packet discarding policy. Congestion management ensures that high-priority services are preferentially processed based on the specified packet scheduling sequence. On a traditional network, quality of services (QoS) is affected by network congestion. Congestion means the low data forwarding rate and delay resulting from insufficient network resources. Congestion results in delay of packet transmission, low throughput rate, and high resource consumption. Congestion often occurs in a complex networking environment where packet transmission and provision of various services are both required. Congestion avoidance and congestion management are two flow control mechanisms for resolving congestion on a network. For the configuration of congestion management on S series fixed switches, see "Example for Configuring Congestion Management (Schedule Template Mode)" in the Typical QoS Configuration. For the comprehensive configuration example of S series fixed and modular switches, see "Example for Configuring Congestion Avoidance and Congestion Management (Using WRR Scheduling and an SRED Policy)" or "Example for Configuring Congestion Avoidance and Congestion Management (Using PQ+DRR Scheduling and a WERD Profile)" in the Typical QoS Configuration.

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