Interactions with RTI Tools
===========================

Topic and type aliasing changes the wire representation of the topic and
type. A topic may be created with the topic name ``Foo`` and type ``ros::String``,
but when the endpoint data is serialized on the wire, it is sent as
topic ``rt/Foo`` and type ``ros::dds_::String_``.

For example, a Wireshark capture of endpoint discovery for a writer on
topic ``testTopic`` that has both ``dds.ros.enable_interoperabilty`` and
``dds.ros.use_mangled_names_as_default`` set to TRUE would appear as
follows:

.. figure:: _static/wireshark1.gif
    :scale: 100 %
    :alt: Wireshark Summary
    :name: WiresharkSummary
    :align: center

.. figure:: _static/wireshark2.gif
    :scale: 80 %
    :alt: Wireshark Detail
    :name: WiresharkDetail
    :align: center

You can see that, although the endpoint is created with topic
``testTopic``, the topic name propagated on the wire (``PID_TOPIC_NAME``) is
``rt/testTopic``, and ``testTopic`` appears under ``PID_TOPIC_NAME_ALIASES``.

RTI Tools have not been updated to account for topic and type aliases,
and will only show the "primary" topic and type names. The endpoint in
this example will appear in the ``rt/testTopic`` topic. For example, here
is how the endpoint appears in *RTI Admin Console*:

.. figure:: _static/admin_topic1.gif
    :scale: 80 %
    :alt: Admin Console ROS Topic
    :name: AdminConsoleROSTopic
    :align: center

Similarly, *RTI DDS Spy* will only print the primary topic and type name in
its output and has not been updated to print topic or type aliases.

The value of ``dds.ros.use_mangled_names_as_default`` determines which
topic name is announced as the “primary” topic name. When this
property is set to ``FALSE``, the endpoint will appear as follows:

.. figure:: _static/admin_topic2.gif
    :scale: 80 %
    :alt: Admin Console DDS Topic
    :name: AdminConsoleDDSTopic
    :align: center

Note the two vertically-oriented grey boxes in the Graphical View: one
endpoint is now shown under ``rt/testTopic`` and one is shown under
``testTopic``. *Admin Console's* "Health Status" indicates that
``testTopic`` is a reader-only (DR) topic and ``rt/testTopic`` is a
writer-only (DW) topic, showing that these are different topics and not
matched; however, in reality they are matched. (This is a current
limitation of using *Admin Console* with topic aliasing, and may be
addressed in future versions of *Connext*.)