MQTT¶
MQTT is light-weight pub-sub messaging protocol often used for machine-to-machine (M2M)/"Internet of Things" communication. It is one of the standard communication protocols defined in ITxPT, and the way vehicles are supposed to communicate with Ruter.
ITxPT
MQTT is a fairly new addition to the ITxPT standard, and is currently a work in progress. Ruter is an active member in the international standard committee.
For more information, see: - MQTT.org - ITxPT
Architecture¶
Two key elements of the architecture are the MQTT broker and the MQTT bridges.
MQTT broker (Ruter)¶
Ruter operates a central MQTT broker that communicates with all the vehicles.
Notice Starting from ADT 3+ all vehicle bridges towards this broker are required to use the MQTT protocol version 5. Support for MQTT v3.1 will be removed at a later stage.
All communication with the MQTT broker is encrypted during transport using TLS 1.2.
MQTT Brokers
To get access to the brokers, please reach out to rdp-support@ruter.no.
| Environment | Hostname | Description |
|---|---|---|
| PROD | mqtt.transhub.io | Production environment. |
| STAGE | mqtt.stage.transhub.io | Test-environment. Used during PTO integration testing and CAT. |
MQTT bridge (On-board Vehicle)¶
The operator is to maintain a MQTT bridge on board the vehicle. The MQTT bridge acts as a proxy and forwards requests back and forth between the vehicle and Ruter.
To get access to the MQTT broker, you need to reach out to Ruter to be provided with credentials.
There is no strict requirement as to what implementation you chose of the mqtt bridge, as long as it is stable and fullfills the standard.
There are multiple open-source solutions to choose from, i.e. https://mosquitto.org.
Example configuration files¶
Updating configurations and DPI content¶
Ruter reserves the right to update the topic configuration and content packages when it deems it necessary.
While the PTO is responsible for setting up the mqtt bridge configuration correctly according to the software running on the vehicle, Ruter provides an api listing all the topics that should be made available for the services on-board the vehicle.
MQTT Topic configurations
| Environment | API version | Topic list | Example config - Mosquitto 2.0 |
|---|---|---|---|
| PROD | ADT3 | https://mqtt-api.transhub.io/v/adt3 | https://mqtt-api.transhub.io/v/adt3/example |
| PROD | ADT2 | https://mqtt-api.transhub.io/v/adt2 | https://mqtt-api.transhub.io/v/adt2/example |
| PROD | ADT1 / OTA | https://mqtt-api.transhub.io/v/adt1 | https://mqtt-api.transhub.io/v/adt1/example |
| STAGE | ADT3 | https://mqtt-api.stage.transhub.io/v/adt3 | https://mqtt-api.stage.transhub.io/v/adt3/example |
| STAGE | ADT2 | https://mqtt-api.stage.transhub.io/v/adt2 | https://mqtt-api.stage.transhub.io/v/adt2/example |
| STAGE | ADT1 / OTA | https://mqtt-api.stage.transhub.io/v/adt1 | https://mqtt-api.stage.transhub.io/v/adt1/example |
These locations should be checked once daily, at a minimum, after 16.00 CET, which is our cutoff for changes for the day, Monday to Friday. It is expected that new bridge configurations should be available on all vehicles running in regular traffic after 05.00 CET the following day.
Additional information¶
A description of the process can be found in the document below: - MQTT topic updates