Warm Line is a feature (since firmware version 10.1.26.0) that initiates an automatic call to a pre-configured number if no other number is dialled during a configurable time limit (e.g. fifteen seconds) after the phone goes off hook.
You can set the target and the timeout time on the WUI:
- Auto Dial Timeout (<auto_dial>): any value between <1> to <2147483647> seconds. Default value is off.
- Auto Dial Target (<auto_dial_target>): Any valid phone number