protected function getDeviceNetworkInfo($serial_number = NULL) {
        $this->prepareForGet();
        $serial_number = $this->getDefaultSerial($serial_number);
        $connection_info = $this->last_status->track->{$serial_number};
        return (object) array(
            'online' => $connection_info->online,
            'last_connection' => date(DATETIME_FORMAT, $connection_info->last_connection/1000),
            'last_connection_UTC' => gmdate(DATETIME_FORMAT, $connection_info->last_connection/1000),
            'wan_ip' => @$connection_info->last_ip,
            'local_ip' => $this->last_status->device->{$serial_number}->local_ip,
            'mac_address' => $this->last_status->device->{$serial_number}->mac_address
        );
    }