The ubiquitous phone call is evolving from just voice to data conferencing which mixes voice and data, and ultimately to video conferencing. Data conferencing works on today's telephone networks and allows people to share applications or use a common whiteboard while they talk in order to collaborate and solve problems together. As network bandwidth expands, video conferencing will become more widespread. Further, these applications will increasingly work well independent of the network infrastructure used—for example, a public switched telephone network, the Internet, or some combination of the two. Microsoft's NetMeeting is an excellent example of this type of collaborative communications tool which spans the Internet and the PSTN.