An IP Service Level Agreement (IP SLA) is a method for using active traffic monitoring — the generation of traffic in a continuous, reliable, and predictable manner — for measuring network performance. Using an IP SLA monitoring policy, you can track network performance and take actions such as permitting, dropping, or bypassing a service device based on service chaining or Policy-Based Redirect (PBR) requirements.

Beginning with the Cisco NSO DC-SDN Core Function Pack (CFP) Release 1.1, you can use NSO to configure IP SLA for L1/L2 and L3 PBR cases. Once defined, an IP SLA monitoring policy can be applied to a PBR policy to define actions (permit, drop, bypass) based on the liveliness of a service device.