Voice messaging

Voice messaging, also known as Voice SMS or Robo Calling, allows Zoom Connect clients to automate calls to landline or mobile phones to deliver a voice message. The message may be a prerecorded audio file in MP3 or wav format, or converted to speech from text.

It is used by companies for a wide variety of business cases including to deliver promotions and offers, emergency messages, PINs for 2-Factor Authentication, and surveys.

The Voice Messaing REST API

Zoom Connect's REST API provides methods for sending audio and text voice messages, receiving delivery reports, and retrieving sent message details. For those who have already sent SMS messages through the API, sending a voice message will be as easy as switching to the Voice Messaging endpoint and adjusting a few parameters. Delivery reports also working in the same manner as the delivery reports for SMS messages.

Please see the Interactive API documentation for details on each API method.

Retrying unanswered calls

The API uses three optional parameters to allow unanswered voice calls to be retried. They are:

  • the number of times to retry the call (maximum of 4 attempts allowed)
  • the minimum interval between retry attempts
  • the maximum interval between retry attempts

Note that while the parameters are optional,if one is provided, all three must be provided.

Attempts at retrying a call follow the following rules:

  • Retry attempts follow a pattern: 1, 2, 5, 10, 20 & 30 minutes, then after 1, 2, 4, 8, 16 and 24 hours.
  • The starting point in the pattern is set by retryMinimumInterval.
  • The ending point in the pattern is set by retryMaximumInterval.
  • If retryMinimumInterval and retryMaximumInterval are equal, the interval between each retry attempt will be equal to the value provided.

Receiving a delivery report

As with SMS messaging, delivery reports received are sent as a POST request to a specified URL. To set the voice messaging delivery report URL please login to Zoom Connect, click on your company name, click on “Developer settings” and paste the URL to which voice message delivery reports are to be forwarded.

	 
	http://yourserver.com/voice/delivery/report.php?
	  nonce=6110900b-a3e3-4ae7-9c80-c446086f8882
	  &status=DELIVERED
	  &messageId=40124213
 	  &campaign=shoe campaign
	  &dataField=custom
	  &checksum=195e39edfffed7e5ac87e85f3a6dd70ed8684b22
	  &nonce-date=20160120103235