MqttDisconnectReasonCode enum

0x00 - Normal disconnection Sent by: Client or Server Description: Close the connection normally. Do not send the Will Message.

0x04 - Disconnect with Will Message Sent by: Client Description: The Client wishes to disconnect but requires that the Server also publishes its Will Message.

0x80 - Unspecified error Sent by: Client or Server Description: The Connection is closed but the sender either does not wish to reveal the reason, or none of the other Reason Codes apply.

0x81 - Malformed Packet Sent by: Client or Server Description: The received packet does not conform to this specification.

0x82 - Protocol Error Sent by: Client or Server Description: An unexpected or out of order packet was received.

0x83 - Implementation specific error Sent by: Client or Server Description: The packet received is valid but cannot be processed by this implementation.

0x87 - Not authorized Sent by: Server Description: The request is not authorized.

0x89 - Server busy Sent by: Server Description: The Server is busy and cannot continue processing requests from this Client.

0x8B - Server shutting down Sent by: Server Description: The Server is shutting down.

0x8D - Keep Alive timeout Sent by: Server Description: The Connection is closed because no packet has been received for 1.5 times the Keepalive time.

0x8E - Session taken over Sent by: Server Description: Another Connection using the same ClientID has connected causing this Connection to be closed.

0x8F - Topic Filter invalid Sent by: Server Description: The Topic Filter is correctly formed, but is not accepted by this Server.

0x90 - Topic Name invalid Sent by: Client or Server Description: The Topic Name is correctly formed, but is not accepted by this Client or Server.

0x93 - Receive Maximum exceeded Sent by: Client or Server Description: The Client or Server has received more than Receive Maximum publication for which it has not sent PUBACK or PUBCOMP.

0x94 - Topic Alias invalid Sent by: Client or Server Description: The Client or Server has received a PUBLISH packet containing a Topic Alias which is greater than the Maximum Topic Alias it sent in the CONNECT or CONNACK packet.

0x95 - Packet too large Sent by: Client or Server Description: The packet size is greater than Maximum Packet Size for this Client or Server.

0x96 - Message rate too high Sent by: Client or Server Description: The received data rate is too high.

0x97 - Quota exceeded Sent by: Client or Server Description: An implementation or administrative imposed limit has been exceeded.

0x98 - Administrative action Sent by: Client or Server Description: The Connection is closed due to an administrative action.

0x99 - Payload format invalid Sent by: Client or Server Description: The payload format does not match the one specified by the Payload Format Indicator.

0x9A - Retain not supported Sent by: Server Description: The Server does not support retained messages.

0x9B - QoS not supported Sent by: Server Description: The Client specified a QoS greater than the QoS specified in a Maximum QoS in the CONNACK.

0x9C - Use another server Sent by: Server Description: The Client should temporarily change its Server.

0x9D - Server moved Sent by: Server Description: The Server is moved and the Client should permanently change its server location.

0x9E - Shared Subscriptions not supported Sent by: Server Description: The Server does not support Shared Subscriptions.

0x9F - Connection rate exceeded Sent by: Server Description: This connection is closed because the connection rate is too high.

0xA0 - Maximum connect time Sent by: Server Description: The maximum connection time authorized for this connection has been exceeded.

0xA1 - Subscription Identifiers not supported Sent by: Server Description: The Server does not support Subscription Identifiers; the subscription is not accepted.

0xA2 - Wildcard Subscriptions not supported Sent by: Server Description: The Server does not support Wildcard Subscriptions; the subscription is not accepted.