This value reports the value of the sysUpTime at the time of the last PPP Link interface creation or deletion in the system. If the number of PPP interfaces has been unchanged since the last re-initialization of the system, then this object contains a zero value. Comparing it against the current sysUpTime tells an admin how recently interfaces were added or removed from this table, useful for correlating a count change with a specific maintenance event. For example, if juniPppSummaryPppLinkIfLastChangeTime matches the timestamp of a known provisioning job, the admin can confirm that job is what changed the interface counts rather than an unplanned event.