class TestController extends \yii\base\Controller
{
    const ROUTE = parent::ROUTE.'/test';
    const SIP = 'sip:[email protected]';

    public $defaultAction = 'welcome';

    /**
     * @throws \yii\base\InvalidArgumentException
     * @throws \Twilio\Exceptions\TwimlException
     */
    public function actionWelcome()
    {
        $response = new Twiml();
        $response->say('Hello. Calling SIP now.', ['voice' => 'alice']);

        $dial = $response->dial();
        $dial->sip(self::SIP, ['username' => 'testuser', 'password' => '*******']);

        echo $response;
    }

    public function actionSip() {
        $response = new Twiml();
        $response->say('Hi. Welcome to your SIP connection.', ['voice' => 'alice']);
        $response->hangup();

        echo $response;
    }
}