What is the best software for video & audio conferencing using broadband for virtual mettings.?

Any software, no matter the cost that is the best for creating virtual meetings between employees at remote location which all have high speed broadband connections. The maximum number of remote participants will be six.

Both Video and audio conferencing is needed however other services such as remote desktop connection and file transfer is not needed.

Can someone please help me. Also does anyone know the requirements to use and setup a system like this. eg. need microphone, webcam, internet 1.5Mbps, etc

Related posts:

1. What’s the best multi-user video conferencing software?
2. What is the best software/hardware combination to do home video conferencing (DSL to DSL)at low cost?
3. What is the best software for video conferencing, especially for distance learning when students are far?
4. Which video conferencing software works well with mac and pc?
5. Is there any free video/audio conferencing class for C?