This value, in seconds, reports how long the current CDMA call has been active. An admin uses this to see at a glance how long the present connection has held up, useful for spotting a session that's about to hit a carrier-imposed call-duration limit or one that's suspiciously short-lived, indicating instability. For example, if this duration resets to near-zero every few minutes, the admin can infer the CDMA call is repeatedly dropping and reconnecting rather than holding a stable session.