This is a read-only counter, in milliseconds, tracking how much voice playout during this call came from data that was received on time, explicitly excluding periods when no voice signal was being sent at all, such as during silence suppression or fax transmission. An admin uses this together with the various gap-fill counters to compute the On Time Playout Rate, a core measure of how cleanly voice data is arriving relative to the total voice playout duration. For example, a low on-time playout value relative to the gap-fill counters would tell an admin the call is suffering substantial jitter or packet loss requiring the receiver to fill gaps rather than play real-time data.