Twilio Gather on Programmable voice - How to access underlying telephony call events

Question

I am trying to automate a call flow to regression test call center application's IVR system.

I am able to place calls and receive the response as expected.But I am trying to understand the time taken between the 2 lines of code

console.log("Waiting for Server to respond");

and

console.log("Received response from Server");

My understanding is after Twilio receives the TwiML response from my Node.js instance, it process and send/receive the telephony signals.

Only after it receives the whole response from the server, I am receiving the voice response in /TC4_Step1_Validate. When I log the timestamp for both the lines and capture the difference. It comes around 20 seconds. But in reality the application responds within couple of seconds.

I believe Twilio waits for the whole dialogue to complete by waiting for 3 second silence, convert that audio stream to text and then post it to my function. That is the reason I see that 20 seconds.

But I need to understand the time it took to first receive the telephony response and not the whole stream with timeout and speech to text conversion time.

In Short I am trying to understand the time it took for the contact center application to respond.

Please find my sample code below

Function to place a call

app.get('/TC4', function(req, res) {
  client.calls.create({
    url: 'http://{PUBLIC_URL}/TC4_Step1',
    to: '{TO_NUMBER}',
    from: '{TWILIO_NUMBER}',
    method: 'GET',
    Record: 'false',  
  })
  .then((call) => res.send(call.sid));   
});

Function to Gather Step 1 response from my contact center application when I place a call

app.get('/TC4_Step1', function(req, res) {
  res.setHeader('Content-Type', 'application/xml');
  const response = new VoiceResponse();
  const gather = response.gather({
    input: 'speech',
    action: 'http://{PUBLIC_URL}/TC4_Step1_Validate',
    timeout: 3,
  });
  res.send(response.toString());
  console.log("Waiting for Server to respond");
  console.log(response.toString());
});

Function to validate response from Step1 & Gather step 2 response

app.post('/TC4_Step1_Validate', function(req, res) {    
  const response = new VoiceResponse();
  console.log("Received response from Server");
  console.log(req.body.SpeechResult.toLowerCase());
  if(req.body.SpeechResult.toLowerCase().indexOf("{VERIFY_TEXT1}")!=-1 && req.body.SpeechResult.toLowerCase().indexOf("{VERIFY_TEXT2}")!=-1) {  
    response.pause({
      length: 2
    });
    const gather = response.gather({
      input: 'speech',
      action: 'http://{PUBLIC_URL}/TC4_Step2_Validate',
      timeout: 3,
    });
  } else {
    console.log("Failed Step 1");
    response.hangup();
  }
  res.setHeader('Content-Type', 'application/xml');
  res.send(response.toString());
  console.log("DTMF Input 2");
  console.log(response.toString());
});

philnash philnash · Accepted Answer · 2017-08-23T13:51:04

Twilio developer evangelist here.

When you set an action attribute, like you have done here with the path /TC4_Step1_Validate, Twilio will only make the call to it once the current action is done. In this case it is waiting for the user to stop speaking for 3 seconds and then, as you suggest, is doing the work with the audio stream to turn it to text and finally call your action URL.

Twilio does not make available other events that specifically represent the start of Twilio's interaction with the call in the case of listening for speech input or indeed most interactions. You can get call events when using <Dial>, but they refer to calls on to a third party.

So, while I don't believe Twilio can do what you're asking for, I'd love to ask what you are trying to achieve overall so I can perhaps help solve the issue another way?

Twilio Gather on Programmable voice - How to access underlying telephony call events

1 Answers