UDP howto refers to the UDP port being "persisted in an application"

[itamar]

TAPs are long gone, the UDP howto still references them though:

As you can see, the protocol is registered with the reactor. This means it may be persisted if it's added to an application, and thus it has startProtocol and stopProtocol methods that will get called when the protocol is connected and disconnected from a UDP socket.

This should discuss startProtocol as equivalent to connectionMade, persistence is wrong and irrelevant.