AT&T Mobility's (NYSE: T) "User-Defined Network Cloud" initiative is aimed at transforming the carrier network. AT&T wants to virtualize hardware functions, cut costs and put more control of its network in the cloud and in the hands of users, both in consumer and enterprise markets. Recently, at AT&T's "Innovation Showcase" in New York, FierceWireless editor Phil Goldstein spoke with Marian Croak, senior VP of Domain 2.0 architecture and advanced services development, about these initatives. Croak talked about the importance of SDN and NFV, what vendors need to do to be part of the initiatives, and why other carriers should get on board. Here's an edited version of that conversation.