The fabric queue selection mechanism is known as fabric QoS.
There are four queues per destination port: (high priority) HP1, HP2, assured-forwarding (AF) and best effort (BE).
By default, internal control traffic is placed in the high-priority queue.
You can configure a fabric QoS policy that defines classification criteria for selecting high-priority or low-priority queue. This is applied to the secure domain router (SDR) (this may be the whole router if no individual service domain routers are
configured) and affects all fabricq ASICs in the logical router.
Of the four levels of priority—HP1, HP2, AF, and BE—AF is unused. From Release 6.6.1 onwards, support for AF is enabled. The enhancement allows for AF and BE traffic to be supported, even while prioritizing
traffic for BE. This provides better quality of service whenever there is a fabric congestion.
A maximum of
four classescan be specified within the policy. A class known as class-default is automatically created and equates to the BE queues. The name of this class cannot be altered. Any name may be applied
to the classes that equate to the priority and AF ports or queues.
fabric QoS checks that all the IPv4, IPv6 and MPLS matches the conditions
configured for all the incoming packets.
The match also
supports Class of Service (CoS).
Fabric QoS policy class maps are restricted to matching a subset
of these classification options:
The fabricq queue selection
mechanism is known as Fabric QoS. To provide class of service to the traffic
under fabric congestion scenarios, configure Fabric QoS. The
platform-independent user interface allows you to configure an MQC policy on
the switch fabric queues. This policy is global for all line cards on the