Sending DTMF in active call can be used to support a variety of voice calling use cases.

For example:

Make a Voice call and need to access a recipient via an extension
Need to send a DTMF during a call to initiate access.

How to send DTMF during an active call

1. Create a Voice Call

Request

curl -X POST \ https://api.syniverse.com/scg-external-api/api/v1/calling/calls \

   -H 'Authorization: Bearer {TOKEN}' \

   -H 'Content-Type: application/json' \

   -d ‘{“from": "USfmJmPpEw4uXRjdQfN9J4","to": "+14085551212"}'

Response

{

    "id": "lVq5omzMQUW1vVlenYGUi5"

}

2. Send DTMF in the Active call initiated above

Using the CallID < lVq5omzMQUW1vVlenYGUi5> received in the response of the Create call request:

curl -X POST \ https://api.syniverse.com/scg-external/api/api/v1/calling/calls/lVq5omzMQUW1vVlenYGUi5/play_dtmf \

  -H 'Authorization: Bearer {TOKEN}' \

  -H 'Content-Type: application/json' \

  -d '{

    "dtmfText": "12345#"

}'

Parameter Description

Parameter: dtmfText , String containing the DTMF characters to be sent in a call. Allows a maximum of 50 characters.

{

    "dtmfText": "12345#"

}

The digits will be sent one-by-one with a marginal delay. Valid characters are given by the regular expression [A-D0-9#*,wW]+.
- The , and lowercase w characters introduce a half-second pause into the DTMF sequence.
- The W character introduces a one-second pause.

Example 1: The DTMF string 1WWW,59# will send a 1, wait 3.5 seconds, then send 59# in quick succession.

{"dtmfText": "1WWW,59#"}'

Example 2 : Send a '1', then '2', then '1', then '#' with a wait time of 1.5 seconds between each character

{ "dtmfText": "1Ww2Ww1Ww#" }

Sending DTMF in Active Call