Conferencing Outbound Calls

Level: Intermediate

In this Learning Lab, you'll create an application that will allow you to enter the phone number of someone to add to a conference call. Once you dial in to the conference call number and enter the other person's number, the application will make an outbound call to this number and place you both into a conference call.


Completion Time: 20 minutes

  • Place two outgoing telephone calls with Javascript
  • Learn how Tropo's conference methodd works
  • Understand how to accomplish simultaneous actions using Tropo's blocking methods.


Creating the application

The application in this lab contains two parts, each represented by a different Tropo application. One part is the conference controller, which takes an incoming call, and asks the caller for a conference ID and a phone number of someone to join to the conference. The other part places an outgoing telephone call to someone and places them in the same conference, using the conference ID chosen by the first part.

We'll start by creating the outbound calling portion.

  1. From the Tropo dashboard, log into your account and click Create New App.
  2. Name your app 'Conference Caller'.
  3. Select Scripting API under the Type of Application.
  4. Open the script editor by clicking the pencil icon titled New script.
  5. Enter the following script, which accepts numberToDial and conferenceID as parameters and adds the called number to a conference call.

    call('+1' + numberToDial);
    say("Welcome. You will be connected to the conference call now.");
    conference(conferenceID, {
       terminator: "*",
       playTones: true,
       onChoice: function(event) {
    say ("Goodbye");
  6. Name your script 'connectToConference.js' and save it.

  7. Select a Country and Region in order to attach a phone number to your application.
  8. Click CREATE APP.
  9. Copy the Voice API Key and paste it into a text document on your computer.

    You'll need this key later on in order to make outbound calls using this script.