Boomerang has partnered with multiple voice carriers to implement a redundant service supporting delivery of Text-to-Speech (TTS) messages and voice calls to both fixed line and mobile telephone numbers. Recipients can respond to messages using their telephone keypad and as this information is matched to the originating message transaction. The following attributes of a voice call are configurable:
- Welcome / Intro message: This is played to the recipient immediately upon answering a voice call and can be used to convey the sender of the message e.g. 'This is a message from Company 123. Press 1 to listen or 2 to ignore"
- Main Message: The content of the message played to the recipient if the Intro Message has been accepted
- Call divert: An organisation can set a contact number to which the recipient will be directed, based on a keystroke selection (9) made during the voice call. It is also possible to set an automated message that is played to the recipient as the call is being diverted
- Exit message: This is played to the recipient on completion of all activities within the voice call
All messages will arrive from a standard telephone number and responses are returned via a keystroke during the main message.
Delivery statuses
A summary of the delivery statuses returned for the different outcomes during a voice call are listed below.
| Status Id | Description |
| D (Delivered) | The call is answered and the recipient has selected ‘1’ during the Intro Message to listen to the main message and the recipient either returns / does not return a keystroke response. |
| F (Failed) | The destination number is invalid / cannot be reached by the carrier or the recipient declines the call. |
| H (Hung) | The call is answered then terminated by the recipient during the Intro Message. |
| R (Rejected) | The call is answered and the recipient has selected ‘2’ during the Intro Message to reject the message at which point the call is terminated. |
| I (Ignored) | The call is not answered by the recipient or the device has been set to ‘Airplane Mode’ and the recipient’s number does have a voicemail or answering service associated with it. |
| E (Expired) | The call is still not answered after the retry policy has been completed. |
| N (No response) | The call has not been answered by the recipient. The status can be returned status can be returned because of one of the following reasons: - the recipient has ignored the call and a voicemail was detected; - the recipient's handset was on airplane mode, therefore it was impossible to reach the handset; - the call has been answered but none of the options provided ("press 1 to listen or 2 to ignore") has been selected; - the call has been declined by the recipient before being answered; - the recipient's has not answered the call but has sent a predefined message from the handset. |
| B (Busy) | The recipient’s number is engaged or the recipient declines the call / recipient responds with a default SMS greeting such as “I can’t talk right now”. |
| T (Retrying) | The retry policy is invoked due when the following statuses are returned (N – No Response, I – Ignored, B - Busy). Retrying is an interim status that is only applied if retry settings have been activated in the customer’s Boomerang account. |
| M (Machine Answered) | The call connected to an answering machine or voicemail service. |
| S (Sent) | A default interim status returned when a call is being made but is not answered and terminal status has not yet been applied. |
The various recipient inputs and different status outcomes are summarised in the TTS Process flow.