MQTT (MQ Telemetry Transport or Message Queue Telemetry Transport) is an ISO standard (ISO/IEC PRF 20922) publish-subscribe-based "lightweight" messaging protocol for use on top of the TCP/IP protocol. It is designed to send short messages from one client (publisher) to another (subscriber) through brokers, which are responsible for message delivery to the end point. RUT routers support this functionality via an open source Mosquitto broker. The messages are sent this way: a client (subscriber) subscribes to a topic(s); a publisher posts a message to that specific topic(s). The broker then checks who is subscribed to that particular topic(s) and transmits data from the publisher to the subscriber. This chapter is a summary of the MQTT function in BEAM iSERIES routers.

MQTT Broker

The Broker will “listen” for connections on the specified Local port. In order to accept connections from WAN, you also need to check Enable Remote Access.

 Field Name
 Value  Description
 Enable  yes | no; Default: no  Toggles MQTT Broker ON or OFF
 Local Port
 integer [0..65535]; Default: "1883"  Specifies the local port that the MQTT broker will listen to
 Enable Remote Access
 yes | no; Default: no  If enabled, MQTT Broker will be reachable by remote user (from WAN)


The MQTT Security tab is used to establish MQTT connection security via TLS/SSL.

 Field Name
 Value  Description
 yes | no; Default: no  Toggles the use of TLS/SSL certificates ON or OFF
 CA File
 .ca file; Default: " "  Certificate authority is an entity that issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate
 CERT File
 .crt file; Default: " " Certificate file is a type of digital certificate that is used by client systems to make authenticated requests to a remote server. Client certificates play a key role in many mutual authentication designs, providing strong assurances of a requester's identity
 Key File
 .key file; Default: " "  Specifies the local port that the MQTT broker will listen to
 TLS Version
 tlsv1.1 | tlsv1.2 | Support all; Default: Support all  Authenticates a client to a server and establishes precisely who they are


The MQTT Broker also supports a functionality called Bridge. An MQTT Bridge is used for the communication between two MQTT Brokers. The window of Bridge parameters is presented below. Some of these are mandatory as they are needed to create a connection: Connection Name, Remote Address and Remote Port. For more information on MQTT Bridge parameters you can read the official mosquitto.conf manual page.

 Field Name
 Value  Description
 yes | no; Default: no  Toggles MQTT Bridge ON or OFF
 Connection Name
 string; Default: " ""  Name of the Bridge connection. Although this is used for easier management purposes, this field is mandatory
 Remote Address
 ip; Default: " "  Remote Broker’s address
 Remote Port
 integer [0..65535]; Default: 1883  Specifies which port the remote broker uses to listen for connections
 Use Remote TLS/SSL
 yes | no; Default: no  Enables the use of TSL/SSL certificates of the remote broker. If this is checked, you will be prompted to upload TLS/SSL certificates. More information can be found in the Security section of this chapter
 Use Remote Bridge Login
 yes | no; Default: no  Enables the use of Remote login data. If this is checked, you will be prompted to enter a remote client ID, username and password
 Topic  string; Default: " "  Specifies the names of the Topics that your Broker will subscribe to
 Try Private
 yes | no; Default: no  Check if the remote Broker is another instance of a daemon
 Clean Session
 yes | no; Default: no  Check to discard session state after connecting or disconnecting


The last section of MQTT Broker parameters is called Miscellaneous. It contains parameters that are related to neither Security nor Bridge.

 Field Name
 Value  Description
 ACL File
 .ACL file; Default: " "  The contents of this file are used to control client access to topics of the broker
 Password File
 password file; Default: " "  The Password file stores user names and corresponding passwords, used for authentication
 yes | no; Default: no  If enabled, connection, subscription and message data will be written to the disk. Otherwise, the data is stored in the router’s memory only
 Allow Anonymous
 yes | no; Default: yes  If enabled, the Broker allows anonymous access

MQTT Publisher

An MQTT Publisher is a client that sends messages to the Broker, who then forwards these messages to the Subscriber.

 Field Name
 Value  Description
 yes | no; Default: no  Toggles the MQTT Publisher ON or OFF
 host | ip; Default: " "  Broker’s IP address or hostname
 integer [0..65535]; Default: 1883  Specifies the port used for connecting to the Broker
 string; Default: " "  Username used for authentication when connecting to the Broke
 Password string; Default: " " Password used for authentication when connecting to the Broker