 Between 2002 and 2004, the company advanced the state of the art in SBC technology, providing customers for the first time with the ability to perform VoIP through existing NAT-enabled firewalls so that residential subscribers could be supported without placing any hardware on their premises.An early customer making great use of this facility was Jeff Pulver's Free World Dialup, which provided free calling services worldwide amongst its subscribers using the SIP VoIP protocol.In 2005, the company was acquired by Ditech Communications (itself later acquired by Nuance Communications) in a deal valued at $24.55m.