protected function getSmsc($number)
    {
        $adapter = $this->getAdapter();
        $adapter->setEndpoint(self::SMSC_ENDPOINT);
        $adapter->setParameters(array(
            'user'     => $this->config['user'],
            'password' => $this->config['password'],
            'msisdn'   => $number
        ));
        $response = $adapter->get();

        return $response->getBody();
    }