The Answering Delay feature allows you to configure the wait time before incoming calls ring on LS trunks. To enable this feature, you must specify the Wait Before Answering Delay (in milliseconds) duration in the EX Controller Web GUI.
Click the POTS tab, and then click FXO Configuration.
In the FXO Answering Configuration table, under Wait Before Answering Delay (ms) column, enter a delay duration for each FXO trunk.
NOTE: The following settings are recommended based on the LS trunk type:
For LS Class trunk to an IP/ONS Class set, enter a duration between 3000 ms and 4000 ms.
For LS trunk (no class) to an IP/ONS set, enter a duration between 1000 ms and 2000 ms.