Downstream Qos: Ethernet Switch; Downstream Qos: Egress Queues - Motorola nvg589 Administrator's Hanbook

Administrator's Handbook
Packet Rx > Filterset Rules:
EF CIR/PIR -> wfq_hi
AF4 CIR/PIR \
AF3 CIR/PIR \
AF2 CIR/PIR > wfq_lo > PQ2 /
AF1 CIR/PIR /
BE CIR/PIR /

Downstream QoS: Ethernet Switch

The simplest way of handling downstream QoS (from WAN to LAN) is to use the per-port queues that
are present in the Ethernet switch. This achieves the greatest efficiency since the queues are handled
in the switch hardware, and should be used when a strict priority queue with 4 priorities is sufficient.
The traffic is classified by priority-bit value. This can be the value retained from WAN ingress (assum-
ing WAN is tagged,) or it can be a value that is set via a filter rule, which allows for advanced classifica-
tion criteria to be used. Even though the LAN interface might not be tagged, there is still an internal
priority field which is used to convey this information to the switch.

Downstream QoS: Egress queues

The secondary method of downstream QoS is to assign egress queues to the LAN port configuration.
This is less efficient, however it allows more advanced queue scheduling algorithms to be used. Pack-
ets are classified by QoS markers set by filter rules.
☛
This method is typically not recommended for deployment configuration as
this mechanism can consume a large amount of CPU processing band-
width.
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Match Rule 1? Set QoS marker = EF
Match Rule 2? Set QoS marker = AF1
Match Rule 3? Set QoS marker = BE
-> PQ1 \
> PQ output to interface Tx
/