My understanding is that CALEA effectively requires you to associate an identity with each active network node, so that requests for a "wiretap" could be addressed more or less in real-time, rather than after the fact. Being able to tap into hardware to observe active network streams is only one piece of the puzzle; you also have to be able to figure out which connections belong the the subject of the wiretap request, which in most cases means associating a name with an IP address.