OAM protocol interactions

The Service Activation Testhead (SAT) is an out-of-service test used to qualify service configuration and performance metrics, including throughput, delay, and packet loss, across various test types. The Packet Link Qualification (PLQ) is an out-of-service physical interface test that verifies the integrity of the physical link. SAT and PLQ cannot coexist on the same complex, as they are disruptive and block each other.

If SAT is actively running on a complex and PLQ is configured on the same complex (using either an ASCI loopback or packet generator), there are two possible outcomes:

• Shared interface resource: If SAT and PLQ require the same interface resource, SAT fails with a service test operational state of stopped-by-fault. This occurs because configuring PLQ for an interface sets the interface operational state to testing, a non-operational state that causes SAT to fail.

• Different interface resources: If SAT and PLQ use different interface resources, SAT continues to run, but attempting to start the PLQ test fails the precondition with the status message: "Test resource not available". This happens because SAT is already consuming the complex resources.

Similarly, if PLQ is configured on an interface (via ASCI loopback or packet generator), it reserves the complex resources, preventing SAT from running successfully:

• Same interface resource: If SAT requires the same interface as the PLQ configuration, it fails to start and produce the error: "Error in /oam/service-activation-testhead/service-test(test-name=test): subinterface is operationally down for stream"

• Different interface resources: If the interfaces differ, SAT attempts to start but fails with a service test operational state of stopped-by-fault, because PLQ is still consuming the complex resources.