mqtt-v5.0-os 07 March 2019
Standards Track Work Product Copyright © OASIS Open 2019. All Rights Reserved. Page 5 of 137
3.1.2.9 Password Flag ................................................................................................................................... 33
3.1.2.10 Keep Alive ........................................................................................................................................ 34
3.1.2.11 CONNECT Properties ...................................................................................................................... 34
3.1.2.11.1 Property Length ........................................................................................................................ 34
3.1.2.11.2 Session Expiry Interval ............................................................................................................. 35
3.1.2.11.3 Receive Maximum .................................................................................................................... 36
3.1.2.11.4 Maximum Packet Size .............................................................................................................. 36
3.1.2.11.5 Topic Alias Maximum ............................................................................................................... 37
3.1.2.11.6 Request Response Information ................................................................................................ 37
3.1.2.11.7 Request Problem Information ................................................................................................... 37
3.1.2.11.8 User Property ........................................................................................................................... 38
3.1.2.11.9 Authentication Method.............................................................................................................. 38
3.1.2.11.10 Authentication Data ................................................................................................................ 38
3.1.2.12 Variable Header non-normative example ......................................................................................... 39
3.1.3 CONNECT Payload ................................................................................................................... 40
3.1.3.1 Client Identifier (ClientID) ................................................................................................................... 40
3.1.3.2 Will Properties .................................................................................................................................... 40
3.1.3.2.1 Property Length .......................................................................................................................... 40
3.1.3.2.2 Will Delay Interval ...................................................................................................................... 41
3.1.3.2.3 Payload Format Indicator ........................................................................................................... 41
3.1.3.2.4 Message Expiry Interval ............................................................................................................. 41
3.1.3.2.5 Content Type .............................................................................................................................. 42
3.1.3.2.6 Response Topic ......................................................................................................................... 42
3.1.3.2.7 Correlation Data ......................................................................................................................... 42
3.1.3.2.8 User Property ............................................................................................................................. 42
3.1.3.3 Will Topic ........................................................................................................................................... 42
3.1.3.4 Will Payload ....................................................................................................................................... 43
3.1.3.5 User Name ......................................................................................................................................... 43
3.1.3.6 Password ........................................................................................................................................... 43
3.1.4 CONNECT Actions .................................................................................................................... 43
3.2 CONNACK – Connect acknowledgement ........................................................................................ 44
3.2.1 CONNACK Fixed Header .......................................................................................................... 45
3.2.2 CONNACK Variable Header ..................................................................................................... 45
3.2.2.1 Connect Acknowledge Flags.............................................................................................................. 45
3.2.2.1.1 Session Present ......................................................................................................................... 45
3.2.2.2 Connect Reason Code ....................................................................................................................... 46
3.2.2.3 CONNACK Properties ........................................................................................................................ 47
3.2.2.3.1 Property Length .......................................................................................................................... 47
3.2.2.3.2 Session Expiry Interval ............................................................................................................... 47
3.2.2.3.3 Receive Maximum ...................................................................................................................... 48
3.2.2.3.4 Maximum QoS ........................................................................................................................... 48
3.2.2.3.5 Retain Available ......................................................................................................................... 49
3.2.2.3.6 Maximum Packet Size ................................................................................................................ 49
3.2.2.3.7 Assigned Client Identifier ........................................................................................................... 49
3.2.2.3.8 Topic Alias Maximum ................................................................................................................. 50
3.2.2.3.9 Reason String ............................................................................................................................ 50
3.2.2.3.10 User Property ........................................................................................................................... 50
3.2.2.3.11 Wildcard Subscription Available ............................................................................................... 50
3.2.2.3.12 Subscription Identifiers Available ............................................................................................. 51
