Egress queues are attached to the port that is used by a Flex PW port to forward traffic (a Flex PW port is bound to one of the ports in the PW port list). In similar fashion, if an egress port scheduler is used, it is attached to the same port. However, the egress port schedulers must be associated by configuration with every port in the PW port list while egress queues are instantiated only on a single port. During a port switchover, egress queues are recreated on the new port and while this is occurring, the failover queue is used to forward traffic. Each port has a single egress failover queue that is used to forward traffic while SAP or subscriber queues are being recreated during transitioning events.
On the other hand, egress port scheduler must be configured by the operator in advance on each port in the PW port list so that it can be ready to treat traffic immediately after its children queues are recreated on this port.
Policers are used on ingress and they do not need to be recreated during port switchover. Instead, they are re-mapped to a new port.
An example QoS configuration is provided below:
Egress port scheduler definition
   
   port-scheduler-policy ‟flex" create
       max-rate 1000000
       group "test" create
       exit
       level 1 rate 100000
   exit
Association between the egress port scheduler and ports
   
   configure  port 1/1/1 
       ethernet
          mode hybrid
          encap-type qinq
          egress-scheduler-policy ‟flex"
       exit
   no shutdown
   configure  port 1/1/2 
       ethernet
          mode hybrid
          encap-type qinq
          egress-scheduler-policy ‟flex"
       exit
   no shutdown
Association between subscriber queues or policers and the egress port scheduler
   
   configure  qos sap-egress 2 
       queue 1 create
          port-parent level 1
          rate 10000
       exit
       queue 2 create 
          port-parent level 1
          rate 10000
       exit
       queue 3 create
          port-parent level 2
          rate 1000
       exit
Applying queue policy to an object:
Subscriber management
   
   configure  subscriber-mgmt sla-profile "sla-profile-1"  
       egress 
          qos 2  
       exit 
					PW SAP in a Layer 2 service
   
   configure  service epipe 10
       sap pw-1:1.2
          egress
          qos 2
       exit
					PW SAP in a Layer 3 service
   
   configure  service vprn 11
       interface ‛flex-int’
          address 1.1.1.1/24
          sap pw-1:1.3
             egress
                qos 2
             exit
       exit
   exit