title: Twilio - Recognising a user has ended a call
body: <p>I am a junior developer currently working on creating our own phone system with Twilio. At the moment when I initiate a call from the client and the customer picks it up at their end its all working well until the user hangups. The call is still remaining connected until I end the call from the browser.
  How can I recognise that the user has ended the call from their end?</p>