Configuration Considerations
• Max 1 level of user defined hierarchy is supported on subinterface.
• Only match queue is allowed in the class in user-define queuing policy-map.
• In user-defined policy-map, all the classes will be in wfq scheduling manner.
• Class-default-q is a self-created class map as part a policy map. It cannot be created nor be destroyed. It will be displayed only when user access it. Executing command "no class-default-q", will un-configure all the configurations of class-default-q.
• User can configure all queuing parameters like weight, priority, queue-limit, wred and shape in a class inside policy.
• Valid priority range is 0-3 and match queue will be 0-3 in case of profile1 and 0-7 in case of profile2.
• Update is possible in the policy-map except the update of match criteria. Once the class with some match criteria is used in a policy-map, it cannot be updated.
• Subinterface queuing can be achieved via vlan-shaping (match interface) as well as via default queues.
• User-defined policy with match subinterface can only be attached on parent interface if subinterface is not attached to user-defined policy-map.
• If user-defined policy with match subinterface is attached on parent interface, sub-interface's default policy-map and port shaper will be removed implicitly from subinterface.
• If the user-defined-policy is applied on parent interface matching subinterface, traffic will go to the queues created via user-defined-service-policy and the queue stats for subinterface will only be displayed via service-policy. The subinterfaces not matched in the user-defined-service policy will go to their own queues only and not to class-default as happens in case of vlan shaping.
• On encap delete from subinterface, all the qos configuration will be removed implicitly from the subinterafce.
• If the port shaper is applied on parent port and on subinterface as well, minimum shape rate will take effect.
• Queue shape percent for subinterface queues, will be calculated as in following manner:
• Percentage will be calculated from the Effective Max speed, which will be calculated as follows:
max_speed = parent_ifp->speed.
If shaper is applied on parent port:
max_speed = parent_port_shaper
If shaper is applied on subinterface:
max_speed = subinterface_shaper
• When only subinterfaces are created with default or no queuing policy-map (when qos is disabled), max supported number of services in case of 4-queue profiles and 8-queue profile are as follows:
QMX : With 4 queues 8K services can be supported but total number of services will be half of the limit supported in case of 8 queues i.e. 4K services approx.
QAX : With 4 queues 4K services can be supported but total number of services will be half of the limit supported in case of 8 queues i.e. 2K services approx.
QUX : With 4 queues 2K services can be supported but total number of services will be half of the limit supported in case of 8 queues i.e. 1K services approx.
• In the case of user-defined queuing, each class represents 1 scheduler each, so it needs to be taken into consideration while configuring max number of services that can be supported with user-defined policy.
• Max number of scheduler and connectors are as follows:
QMX: BCM88370_B0
MAX_NUM_CL_SCHD_QMX 16384
MAX_NUM_FQ_SCHD_QMX 16128
QAX: BCM88470
MAX_NUM_CL_SCHD_QAX 7936
NUM_FQ_SCHD_QAX 7936
QUX: BCM88270
MAX_NUM_CL_SCHD_QUX 4096
MAX_NUM_FQ_SCHD_QUX 3840
Max number of Voqs that can be created will be derived from below formula:
MAX_NUM_VOQ_CONN_QMX (((64*1024)/NUM_CUSTOM_QUEUE)/2)
MAX_NUM_VOQ_CONN_QAX (((32*1024)/NUM_CUSTOM_QUEUE)/2)
MAX_NUM_VOQ_CONN_QUX (((16*1024)/NUM_CUSTOM_QUEUE)/2)
Where NUM_CUSTOM_QUEUE will be based upon service-queue profile set. i.e. 4 for profile1 and 8 for profile2.
Scheduler and queues used for physical interfaces are included in these.
• Subinterface queuing is not supported for lag subinterface and L2VPN/ELINE services on Q1 devices (QMX/QAX/QUX).
• When multiple traffic class is mapped to single service queue i.e tc 1,2,3 are mapped to queue1, traffic load shared between the traffic class inside the particular queue randomly.
Last modified date: 10/20/2023