Traffic Management Support; Frame Relay Traffic Management; Ingress Sap Classification And Marking; Egress Network Exp Marking - Alcatel-Lucent 7750 SR Manual

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Traffic Management Support

Traffic management of Frame Relay VLLs is achieved through the application of ingress and

egress QoS policies to SAPs like other Frame Relay SAPs. No queuing occurs on the MDA; all

queuing, policing and shaping occurs on the IOM and, as a result, traffic management is

forwarding-class-aware. Forwarding classes may be determined by inspecting the DSCP marking

of contained IP packets (for example) and this will determine both the queuing and the EXP bit

setting of packets on a Frame Relay VLL.

DE=0 frames are subject to the CIR marking algorithm in the IOM queue. Drop preference for

these packets will follow the state of the CIR bucket associated with the ingress queue. The value

is marked in the drop preference bit of the internal header and into the DE bit in the Q.922 frame

header. DE=1 frames are classified into "out-of-profile" state and are not be overwritten by the

CIR marking in the ingress IOM queue. The drop preference is set to high.

FC-to-EXP mapping is as per the Network Egress QoS policy. Marking of the EXP field in both

label stacks is performed.

Classification is based on the EXP value of the pseudowire label and EXP-to-FC mapping is as per

Network Ingress QoS policy.

7750 SR OS Services Guide