The num-qos-classifiers parameter cannot be modified when the policy is in use (for example, when it is associated with a SAP). Other parameters in the SAP ingress policy can be changed.
When changing other parameters for a policy that is in use (for example, fc meter map or fc classification match criteria entries), the system recomputes the resources required to accommodate the change. If the resources required exceeds the configured value for num-qos-classifiers, the change is not allowed.
If more resources are needed than the value configured in num-qos-classifiers for a existing policy, then the following options are available:
Copy the existing policy to a new policy, modify the num-qos-classifiers parameter, modify the match criteria entries, and modify the SAP configuration to associate it with the new policy.
Ensure the existing policy is not in use by any SAP (if required, change the SAP configuration to disable the use of the QoS policy with the no qos form of this command), change all the required parameters, and finally modify the SAP configuration to use the policy again.
Both options above have side effects; for example, they can reset the statistics associated with the meters and can potentially cause existing traffic classification not to take effect. However, the system ensures that the default policy is used during the period when policy changes are being made after the two options are performed.
The following items are additional service ingress policy configuration considerations:
In releases before Release 3.0R1, the system always computes the number of resources (like classifiers and meters) required by a policy assuming the number of resources will be used in a VPLS service. This allows the policy to be applied to either an Epipe or VPLS service.
From Release 3.0R1 onwards, on creation of SAP ingress policy, the system does not compute the number of resources required by a policy and validate the number against resources available in the system. The system validates the resources needed only when the SAP ingress policy is attached to a SAP. If enough resources are available the association succeeds, otherwise the system fails the CLI command. Based on the service in which the SAP is configured (such as VLL, VPLS, and so on), for the same SAP ingress policy the amount of resources required is different. The system validates that the amount of QoS resources specified in the num-qos-classifiers command is sufficient for the match criteria, forwarding class, and service specified and that the resources are available in hardware. On failure of the validation, the system disallows the association of the SAP ingress policy with the SAP.
The match criteria type (that is, mac-, ipv4-, and ipv6-criteria) cannot be changed when the SAP ingress QoS policy is in use. For example, if the match-criteria is set to ipv4-criteria and the policy is associated with a SAP, then the ipv6-criteria or mac-criteria cannot be enabled in the same policy. If there is a need to change the criteria, users must remove the association and then change the SAP ingress policy to use the new match criteria. For SAPs configured in VPRN services, the computation of resources is similar to an SAP configured in an Epipe service.
See Resource allocation for service ingress QoS policies using CAM-based classification for more information.