Service for Linked Learning Centers

I am currently participating in research for a project grant proposal that would ultimately result in 5 enhanced learning centers--one in the United States and 4 in Africa, namely Rwanda, Uganda, Tanzania, and the DRC. Ideally we want to have the 5 centers linked and able to transmit live IP Video to and from each site. As we see it, this would require about 128 KBPS upload and download speed. We would also have Internet enabled computer labs.

We're just getting started looking into our options. Any suggestions for good services that could meet these needs?

Thanks!