This Integer32 reports the Calculated Planning Impairment Factor for a fallback probe, computed as total impairment minus the configured fallback Expectation Factor, with a value of 0 meaning it was not calculated for that attempt. Administrators use it specifically to evaluate the voice quality of automated fallback/probe attempts rather than actual user calls, which supports proactive quality-based routing decisions. For example, a consistently high fallback Icpif on probes to a particular destination could trigger a gateway's fallback logic to reroute real calls away from that degraded path.