MQTT over TCP Bridge
The MQTT over TCP Bridge is a key feature of EMQX Edge that enables reliable, bi-directional communication between your local edge broker and remote MQTT brokers using standard TCP connections. This bridge is especially suited for IoT edge-to-cloud scenarios, ensuring data reliability, message integrity, and connectivity across network boundaries such as firewalls or proxies.
What Is MQTT over TCP Bridge?
The MQTT over TCP Bridge establishes an outbound connection from EMQX Edge to a remote MQTT broker such as EMQX Platform, using the MQTT protocol over TCP or TLS.
This bridge allows you to:
- Forward MQTT messages from local topics to the cloud or another broker.
- Receive messages from remote topics into local topics.
- Maintain QoS-based message delivery even across unstable networks.
- Configure message caching and automatic resend when reconnecting.
Key Features
- Protocol Support: MQTT v3.1, v3.1.1, and v5.0 over TCP or TLS.
- Bi-directional Bridging: Both publish (forward) and subscribe (receive) across brokers.
- Automatic Reconnect: Handles disconnection and reconnection with optional message buffering.
- Parallel Connections: Support for concurrent parallel processes to improve throughput.
- Full Dashboard Integration: Configure, monitor, and manage bridges through a visual UI.
How It Works
The MQTT over TCP Bridge consists of three components:
- Connector: Establishes the connection to the remote MQTT broker using TCP or TLS.
- Forwards: Rules for sending messages from local topics to remote topics.
- Subscriptions: Rules for receiving messages from remote topics to local topics.
The bridge manages message queues, QoS levels, and connection lifecycles internally to ensure reliability even in challenging network environments.
What's Next
- Follow the Quick Start Guide to create your first MQTT over TCP bridge.
- Explore the Advanced Configuration Guide to learn about topic mapping, hybrid bridging, message caching, and more.