IoT Platform:Troubleshooting

IoT Platform uses the standard MQTT protocol. For more information, see the MQTT 3.1 and 3.1.1 specification and the MQTT 5.0 specification.

The following tables list the server-side return codes for MQTT connections.

• MQTT 3.1 and 3.1.1

  Return code	Return message	Cause
  0	0x00 Connection Accepted	The connection is successful.
  1	0x01 Connection Refused, unacceptable protocol version	The server does not support the MQTT protocol version requested by the device.
  2	0x02 Connection Refused, identifier rejected	The clientId parameter is invalid or does not comply with the format specified by IoT Platform. For example, the value exceeds the length limit or an extended parameter has an incorrect format.
  3	0x03 Connection Refused, Server unavailable	The network connection is established, but the MQTT service is unavailable.
  4	0x04 Connection Refused, bad user name or password	The username or password parameter is invalid.
  5	0x05 Connection Refused, not authorized	The device is not authorized.

• MQTT 5.0

  Return code	Return message	Cause
  0	0x00 Success	The connection is successful.
  128	0x80 Unspecified error	An unspecified error occurred.
  129	0x81 Malformed Packet	A malformed packet was received.
  130	0x82 Protocol Error	A protocol error occurred.
  132	0x84 Unsupported Protocol Version	The protocol version is not supported.
  136	0x88 Server unavailable	The server is unavailable.
  137	0x89 Server busy	The server is busy.
  138	0x8A Banned	Access is prohibited.
  140	0x8C Bad authentication method	The authentication method is invalid.
  141	0x8D Keep Alive timeout	A keepalive timeout occurred.
  144	0x90 Topic Name invalid	The topic name is invalid.
  147	0x93 Receive Maximum exceeded	The maximum number of received messages is exceeded.
  148	0x94 Topic Alias invalid	The topic alias is invalid.
  149	0x95 Packet too large	The packet length exceeds the limit.
  150	0x96 Message rate too high	The message transmission rate is too high.
  151	0x97 Quota exceeded	The quota is exceeded.
  152	0x98 Administrative action	An administrative action occurred.
  153	0x99 Payload format invalid	The payload format is invalid.
  154	0x9A Retain not supported	Message retention is not supported.
  155	0x9B QoS not supported	The Quality of Service (QoS) level is not supported.
  156	0x9C Use another server	Use another server.
  157	0x9D Server moved	The server has been moved.
  158	0x9E Shared Subscription not supported	Shared subscriptions are not supported.
  159	0x9F Connection rate exceeded	The connection rate is exceeded.