Table of contents
Configuring Ports to Trust DSCP Priority
Configure Congestion Management
Configure Congestion Avoidance
Apply the queue profile on the outbound interface
QoS is managed in a class-based manner (implemented by scheduling 0~7 queues, generally 6 and 7 protocols are reserved for routing protocols, so we only use 0~5 queues)
Prioritize routes
192.168.10.0/24 network segment DSCP priority is EF
192.168.20.0/24 network segment DSCP priority is CS4
The DSCP priority of the network segment 192.168.30.0/24 is AF31
The DSCP priority of network segment 192.168.40.0/24 is AF32
The DSCP priority of other network segments is default
Configure acl to match routes
acl number 3000
rule 5 permit ip source 192.168.10.0 0.0.0.255
acl number 3001
rule 5 permit ip source 192.168.20.0 0.0.0.255
acl number 3002
rule 5 permit ip source 192.168.30.0 0.0.0.255
acl number 3003
rule 5 permit ip source 192.168.40.0 0.0.0.255
acl number 3004
rule 5 permit ip source 192.168.50.0 0.0.0.255
rule 10 permit ip source 192.168.60.0 0.0.0.255
Define the traffic policy and remark the priority of the corresponding route
traffic classifier EF operator or
if-match acl 3000
traffic classifier AF31 operator or
if-match acl 3002
traffic classifier CS4 operator or
if-match acl 3001
traffic classifier other operator or
if-match acl 3004
traffic classifier AF32 operator or
if-match acl 3003
traffic behavior EF
remark dscp ef
traffic behavior AF31
remark dscp af31
traffic behavior CS4
remark dscp cs4
traffic behavior other
remark dscp default
traffic behavior AF32
remark dscp af32
traffic policy QoS
classifier EF behavior EF
classifier CS4 behavior CS4
classifier AF31 behavior AF31
classifier AF32 behavior AF32
classifier other behavior other
Apply traffic policy on the interface, and mark the priority when sending out
interface GigabitEthernet0/0/0
ip address 100.0.12.1 255.255.255.0
traffic-policy QoS outbound
You can see the configured DSCP priority from the sent data packets
Configuring Ports to Trust DSCP Priority
The device searches the priority mapping table according to the DSCP priority carried by the message, and determines the queue into which the message enters (that is, there is a mapping relationship between DSCP and the queue)
For example: queue 5 corresponding to DSCP EF
DSCP CS4 corresponds to queue 4
DSCP AF31 and AF32 correspond to queue 3
interface GigabitEthernet0/0/0
ip address 100.0.12.2 255.255.255.0
trust dscp
Configure Traffic Policing
192.168.50.0 network segment is configured with traffic policing in the direction of the incoming interface, and the promised information rate is 8kbit/s
interface GigabitEthernet0/0/1
qos car inbound source-ip-address range 192.168.50.0 to 192.168.50.255 cir 8
Configure Congestion Management
Configure a queue template named dscp
qos queue-profile dscp
queue 3 weight 30 The weight of queue 3 is 30
queue 4 weight 50 The weight of queue 4 is 50
schedule wfq 0 to 4 pq 5 Queues 0~4 are scheduled using wfq , and queue 5 is scheduled using pq
queue 3 drop-profile dscp
Configure Congestion Avoidance
Configure the wred discard template, named dscp
drop-profile dscp wred dscp 配置wred丢弃模板基于dscp优先级来丢弃 dscp af31 low-limit 50 high-limit 80 discard-percentage 40 为DSCP优先级为AF31的流量做丢弃策略（丢弃门限为50~80，丢弃概率为40%） dscp af32 low-limit 40 high-limit 60 discard-percentage 50 为DSCP优先级为AF32的流量做丢弃策略（丢弃门限为40~60，丢弃概率为50%）Reference the drop template in the queue template
qos queue-profile dscp queue 3 drop-profile dscp af31和af32对应的队列都是队列3，所以在队列3上绑定丢弃模板
Configure Traffic Shaping
Configure traffic shaping under the queue profile
qos queue-profile dscp
queue 0 to 2 gts cir 8 cbs 1500 Configure traffic shaping for queue 0~2 , the committed information rate is 8kbit/s , and the instantaneous traffic is 1500kbit/s
Apply the queue profile on the outbound interface
interface GigabitEthernet0/0/1
qos queue-profile dscp
Verify the configuration
Check the queue template information - including the scheduling mode and weight corresponding to the queue, as well as the configured traffic shaping information
View the discarding discarding profile - including the discarding policy corresponding to each DSCP priority /IP
View configured traffic policing information
