The National Library of Medicine provides a testbed environment demonstrating the use of MPEG-2 videoconferencing and NTSC quality video over Internet2 networks and the Next Generation Internet (NGI) for use in telemedicine/consultation and distance learning programs. Quality of service requirements for healthcare applications on high-performance networks are being researched concerning the integrity of the information being transmitted and the value added by real-time interaction. The testbed environment allows point to point and multi-point videoconferencing (via multicast) between collaborating sites, and also allows transmission of a range of medical content from varied sources, including presentation stands, videomicroscopes, videotape, digital stethoscopes, and otoscopes. Demonstrations of the technology are ongoing and configuration of the testbed continues to evolve.