idleTimeoutSec property
Specifies how long to keep a Connection Tracking entry while there is no matching traffic (in seconds).
For internal passthrough Network Load Balancers: - The minimum (default) is 10 minutes and the maximum is 16 hours. - It can be set only if Connection Tracking is less than 5-tuple (i.e. Session Affinity is CLIENT_IP_NO_DESTINATION, CLIENT_IP or CLIENT_IP_PROTO, and Tracking Mode is PER_SESSION). For external passthrough Network Load Balancers the default is 60 seconds. This option is not available publicly.
Implementation
core.int? idleTimeoutSec;