Overview
On a FR interface, you can use generic QoS services to perform traffic policing, traffic shaping, congestion management, and congestion avoidance. You can also use FR-specific QoS mechanisms, including FR traffic shaping, FR traffic policing, FR congestion management, FR discard eligibility (DE) rule list, and FR queuing management.
FR QoS is more flexible than generic QoS. It works on a per PVC basis, and generic QoS works on a per interface basis. For more information about Frame Relay, see HPE FlexNetwork MSR Router Series Comware 5 Layer 2—WAN Configuration Guide.
Figure 42: FR QoS implementation
FR QoS uses these parameters:
CIR ALLOW—Average transmission rate guaranteed on a VC. When no congestion occurs, CIR ALLOW is guaranteed for data transmission.
CIR—Minimum transmitting rate that an FR VC provides. CIR is guaranteed for data transmission even if congestion occurs in the network.
CBS—Traffic that an FR VC is committed to transmit within the interval of Tc. When congestion occurs in the network, transmitting traffic of the CBS size is guaranteed by the FR network.
EBS—Maximum traffic that can exceed CBS on an FR VC within the interval of Tc. When congestion occurs in the network, the traffic of EBS is dropped first. Transmitting traffic of the EBS size is not guaranteed by the FR network.