D-Link DIR-853 User Manual page 110

DIR-853 AC1300 MU-MIMO Wi-Fi Gigabit Router
with 3G/LTE Support and USB Port 3.0
User Manual
Parameter
Number of inspections
of inactive connection
When all needed settings are configured, click the APPLY button.
A number of requests that will be sent in order to analyze the status
of the main connection when the connection is inactive (the router
uses the reserve connection as a default gateway).
Page 110 of 228
Configuring via Web-based Interface
Description