Can I use Wireshark to inspect the user data of my samples?
No. The RTPS dissector does not deserialize the serialized data. It only dissects the RTPS protocol-related fields.
Why do I see some bytes set to 0 that are not dissected between fields?
Those bytes are padding inserted for alignment purposes.
Why can’t I see the topic in the dissection of a DATA packet?
There is a feature called Topic Information that can show you the Topic’s name. (It is disabled by default.) See Section 2.5 in this document.
Where can I find more information about the RTPS specification?
How can I tell when discovery has finished?
Can I use Wireshark to inspect data through shared memory?
How can I capture traffic being sent through shared memory?