MQTT feature support in MQTT broker

Important

Azure IoT Operations Preview – enabled by Azure Arc is currently in preview. You shouldn't use this preview software in production environments.

You'll need to deploy a new Azure IoT Operations installation when a generally available release is made available. You won't be able to upgrade a preview installation.

See the Supplemental Terms of Use for Microsoft Azure Previews for legal terms that apply to Azure features that are in beta, preview, or otherwise not yet released into general availability.

MQTT broker currently supports the following MQTT features and control packets.

Feature or control packet MQTT v3.1.1 MQTT v5
CONNECT Keep-Alive Supported Supported
CONNECT Will Messages Supported Supported
CONNECT Clean Start Supported
CONNECT Persistent session Supported
CONNECT Session Expiry Interval Supported
CONNECT Receive Maximum Supported
CONNECT Maximum Packet Size
CONNECT Topic Alias Maximum
CONNECT Request Response Information
CONNECT User Properties Supported
CONNECT Authentication Data
CONNECT Authentication Method
CONNECT Session Present flag (Persistent session) Supported Supported
CONNECT Server Generated Client ID Supported Supported
AUTH
PUBLISH QoS0 Delivery Supported Supported
PUBLISH QoS1 Delivery Supported Supported
PUBLISH QoS0 Offline messages for persistent sessions Supported Supported
PUBLISH QoS1 Offline messages for persistent sessions Supported Supported
PUBLISH QoS1 Flow control
Currently, the broker sends out as many publishes as possible without waiting for the client to acknowledge them.
Supported Supported
PUBLISH QoS1 Message delivery retry Supported Supported
PUBLISH QoS0 Retain Supported Supported
PUBLISH QoS1 Retain Supported Supported
PUBLISH Correlation Data Supported
PUBLISH Response Topic Supported
PUBLISH Payload Format Indicator Supported
PUBLISH Message Expiry Interval Supported
PUBLISH Topic Alias
PUBLISH User Properties Supported
SUBSCRIBE Supported Supported
SUBSCRIBE Retain as Published Supported
SUBSCRIBE Retain Handling Supported
SUBSCRIBE Wildcards Supported Supported
SUBSCRIBE No Local
UNSUBSCRIBE Supported Supported
SUBSCRIBE $SYS topics
SUBSCRIBE Subscription Identifiers
SUBSCRIBE Shared Subscriptions Supported Supported
SUBSCRIBE Max subscriptions per client
PINGREQ Supported Supported
DISCONNECT Supported Supported
DISCONNECT Session Expiry Interval