If the payload of UDP on certain ports is Protobuf encoding, Wireshark use this table to know which Protobuf message type should be used to parsing the data on the specified UDP port(s).
The configuration for UDP Port(s) to Protobuf message type maps is a user table, as described in Section 11.7, “User Table”, with the following fields:
Tips: You can create your own dissector to call Protobuf dissector. If your dissector is
written in C language, you can pass the message type to Protobuf dissector by
parameter of call_dissector_with_data() function. If your dissector is written in Lua, you
can pass the message type to Protobuf dissector by
pinfo.private["pb_msg_type"]. The format
helloworld is package name,
HelloRequest is message type.