Up until a while ago, when incoming-call providers facilitating VoIP applications started making their appearance, communication between VoIP users and any fixed telephone communication system had not been feasible. Lately, the VoIP communications have been widely accepted by the majority of the PC users but also they tend to replace the traditional home telephony.
CDRInfo presents a brief article
describing the basic technologies behind the VoIP communications as well as the main steps consumers should follow in order to set up a VoIP connection on a PC. Take some time and read it here