cloud9でIoTにtopicを発行したい

Cloud9にSDKを入れて、IoTコアに対してtopicを発行したい。
しかしながら、”class shadow Error”が出てすぐにタイムアウトになってしまう
deviceMain.pyは、既にcloud9に入っており、モノの名前とエンドポイントを指定するとsendできるはずである。
ご教示くださいませ

アカウント:~/environment/DummyDevice $ python3 deviceMain.py --device_name モノの名前 --endpoint エンドポイント名

device_name: ＊＊＊＊＊
endpoint: ＊＊＊＊＊
rootca cert: ＊＊＊＊＊
private key: ＊＊＊＊＊
certificate: ＊＊＊＊＊
connect to AWS IoT >>>
Connect timed out
class shadow Error
Error main()
Traceback (most recent call last):
File "deviceMain.py", line 48, in device_main
iot_client.create_shadow()
File "/home/ec2-user/environment/DummyDevice/iotCommon.py", line 136, in create_shadow
raise e
File "/home/ec2-user/environment/DummyDevice/iotCommon.py", line 122, in create_shadow
self._shadow_client.connect(self.KEEPALIVE)
File "/usr/local/lib/python3.6/site-packages/AWSIoTPythonSDK/MQTTLib.py", line 1271, in connect
return self._AWSIoTMQTTClient.connect(keepAliveIntervalSecond)
File "/usr/local/lib/python3.6/site-packages/AWSIoTPythonSDK/MQTTLib.py", line 513, in connect
return self._mqtt_core.connect(keepAliveIntervalSecond)
File "/usr/local/lib/python3.6/site-packages/AWSIoTPythonSDK/core/protocol/mqtt_core.py", line 199, in connect
raise connectTimeoutException()
AWSIoTPythonSDK.exception.AWSIoTExceptions.connectTimeoutException