This read-only Unsigned32 value, in seconds, reports how long a port-level PRBS test has been running. As with its facility-level counterpart, this gives operators the elapsed-time context needed to judge whether the accompanying bit-error count represents a meaningful pass/fail result for the port under test. For example, a testSignalStatusTestTimeDuration of 600 seconds with zero errors would support a quick 10-minute port-loopback sanity check before turning a port over to service.