In addition to marking values, the access egress QoS policy provides an option to define port-based queues and scheduling when per port queues are used for SAPs configured on access ports.
Users have an option to use either port-based egress queuing and shaping or SAP-based egress queuing and shaping for SAPs configured on access ports or hybrid ports. Use the configure system resource-profile qos port-scheduler-mode command on 7210 SAS-Mxp or the configure system global-res-profile qos port-scheduler-mode on the 7210 SAS-R6 and 7210 SAS-R12 to select the mode to be used for SAPs configured on all the ports of the node. When port-scheduler-mode is enabled, software uses 8 egress queues per access port and all the SAPs configured on the port will share the 8 egress queues for traffic sent out of that port. In this mode, SAPs configured on hybrid port shares the egress queues with network port traffic. Enabling port-scheduler-mode affects the behavior for all the SAPs configured on either access or hybrid port. That is, port-based egress queues is mutually exclusive to use of SAP-based egress queues. When port-scheduler-mode is enabled, per port egress queues are defined using the access egress policies.
Additionally, the marking values used to mark traffic from different forwarding classes is defined by the remark policy in the access egress policy. In other words, per SAP marking cannot be used when Port-based queuing mode is used. A remarking policy can be defined for each access egress policy and remarking is disabled by default. Only remarking policy of type dot1p, dot1p-lsp-exp-shared, dscp or dot1p-dscp can be used with access-egress policy. The following is the marking behavior with different remark policy types:
If the remark policy type is dot1p or dot1p-lsp-exp-shared, all traffic sent out of Layer 2 SAPs and Layer 3 SAPs configured on that port will have its Dot1p bits marked.
If the remark policy type is dscp, all traffic sent out of Layer 2 SAPs and Layer 3 SAPs configured on that port will have its IP DSCP bits marked (assuming Layer 2 SAPs are carrying IP traffic).
If remark policy is of type dot1p-dscp, all traffic sent out of Layer 2 SAPs and Layer 3 SAPs configured on that port will have its IP DSCP bits (assuming Layer 2 SAPs are carrying IP traffic) and Dot1p bits marked.
When port-scheduler-mode is disabled, per-SAP egress queues are available for use. Per-SAP egress queues are configured in the service egress policies.
On the 7210 SAS-Mxp, 7210 SAS-R6, and 7210 SAS-R12, when port-based queuing is enabled, RVPLS SAPs use the port-based egress queues for both unicast and BUM traffic; all the SAPs, including RVPLS SAPs, share the eight egress queues created per port.
Access egress QoS policies define egress queues and map forwarding class flows to queues, if port-scheduler-mode is enabled. In port-scheduler-mode, the system allocates 8 queues to access port egress by default. To define a basic access egress QoS policy, the following are required:
unique access egress QoS policy ID
QoS policy scope of template or exclusive
The parameters that can be configured for a queue are discussed in Queue parameters.
Optional service egress QoS policy elements include:
specify remark policy that defines IEEE 802.1p priority value remarking based on forwarding class
When port-based queuing is used, the FC to queue map is fixed and the queues priority is determined by the queue number, with higher queue number having the higher priority. The user can configure a queue to be a strict queue to change the scheduling behavior for that queue.
The following is a sample configuration output showing a default access-egress policy for the 7210 SAS-Mxp, 7210 SAS-R6, and 7210 SAS-R12.
*A:sasr_dutb>config>qos>access-egress# info detail
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description "Default Access egress QoS policy."
no remarking
remark 2
scope template
queue 1
adaptation-rule cir closest pir closest
rate cir 0 pir max
queue-mgmt "default"
queue-mode weighted
weight 1
exit
A:sasr_dutb>config>qos>access-egress#