This reports the negotiated lifetime, in seconds, of this specific Phase-1 tunnel, per its description - the actual agreed-upon value from this negotiation, which could differ from a configured policy's lifetime if the peer proposed something shorter and the two sides settled on the lower value. Comparing this to the configured cipsIsakmpPolLifetime tells an admin whether this specific tunnel is rekeying more or less often than the local policy alone would suggest. A tunnel showing a negotiated lifetime of 3600 seconds when the local policy specifies 86400 reveals the peer's shorter setting won out during negotiation.