Configuring Cyclone DDS for Wifi + Ethernet connection on an Enterprise Network (for ROS2)

DDSConfig.md

Configuring Cyclone DDS for Wifi + Ethernet connection on an Enterprise Network (for ROS2)

For communication between wifi and ethernet devices, the DDS layer in ROS2 relies on the multicast ability of a given network.

This is often disabled on enterprise networks (at university or work etc) for (I think) security reasons .

To get around this, you have to configure CycloneDDS to comunicate in a unicast manner, and you must specify the local IPs of all the participants you want to communicate.

I am using CycloneDDS instead of the default (for ROS2 humble at least) FastDDS, because I ran into lots of issues trying to get topic discovery to work properly in a unicast manner.

ROS2 setup with Cyclone DDS

• Install cyclonedds on your respective ros distro (replace <ros-distro> with your ros distribution, e.g. humble)

sudo apt install ros-<ros-distro>-rmw-cyclonedds-cpp

• Switch to cyclone as your ros2 rmw (robot middle ware). I recommend placing this command in your .bashrc, so that it's called every time you launch your terminal.

export RMW_IMPLEMENTATION=rmw_cyclonedds_cpp

• Add an environment variable to the cyclone configuration xml file (again, add this to your .bashrc)

export CYCLONEDDS_URI=/path/to/the/xml/profile

• Create a cyclone dds congiguration file called cyclonedds.xml, that disables multicast, and specifies the (static) IPs of the devices in the network

<?xml version="1.0" encoding="UTF-8" ?>
<CycloneDDS xmlns="https://cdds.io/config" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="https://cdds.io/config https://raw.githubusercontent.com/eclipse-cyclonedds/cyclonedds/master/etc/cyclonedds.xsd">
    <Domain Id="any">
        <General>
            <Interfaces>
                <NetworkInterface autodetermine="true" priority="default" />
            </Interfaces>
            <AllowMulticast>false</AllowMulticast>
            <MaxMessageSize>65500B</MaxMessageSize>
        </General>
        <Discovery>
            <EnableTopicDiscoveryEndpoints>true</EnableTopicDiscoveryEndpoints>
        <ParticipantIndex>auto</ParticipantIndex>
        <MaxAutoParticipantIndex>50</MaxAutoParticipantIndex>
            <Peers>
                <Peer Address="192.30.58.232"/>
                <Peer Address="143.167.46.22"/>
                <Peer Address="143.167.47.43"/>
            </Peers>
        </Discovery>
        <Internal>
            <Watermarks>
                <WhcHigh>500kB</WhcHigh>
            </Watermarks>
        </Internal>
    </Domain>
</CycloneDDS>

Now, even on an enterprise network, you can communicate with ROS2 between wifi and ethernet based devices. Enjoy /:)