# RAD Failure Detection

Three types of failures can occur with customer provided RADs and are as follows:

- No Answer Failure: A 30 second timer detects a no answer condition. If the RAD has not answered after 30 seconds of ringing, the system assumes a no answer failure condition. Note that ONS Type RADs will fail after a single no answer condition; whereas, embedded RADs require two subsequent No Answer conditions to fail.

- Failure to Clear Down: Expiration of the Answer Plus Expected Offhook Timer in the RAD's Class of Service indicates to the system that the RAD has not cleared down. This timer has a programmable range of 0 to 255 seconds.

- False Origination: RADs are only able to answer a call. The system detects a false origination from the RAD using system intercept handling.

When a RAD failure occurs, the system sends a failure message (in the form of a Callback Message) to the designated RAD maintenance set. RAD Failure, followed by the RAD extension number or name, and time of the failure is displayed. For information about programming a RAD maintenance set, refer to Program Recorded Announcement Device (RAD).

Related Topics

- RAD Description

- RAD Groups

- Types of RADs

- RAD Maintenance

- RAD Front End Messaging

- RAD Testing

- RAD - Attendant Overflow