The interaction between connected H.323 and H.320 videoconferencing systems is complicated. Video performance is strongly affected by the nature and speed of the processors at each end, but also by the choices of audio compression algorithms in use. Video performance, measured by delivered frame rates, depends most strongly on the power and efficiency of the encoding processor. Add the MMX instruction set, and the output should increase to about 10 fps. One inference to be drawn from our tests is that implementation of the new H.323 standards suite is still in its infancy.
Developers have a lot to learn about configuring and fine-tuning their systems.
And you'll be able to update and improve most systems as vendors release updates. Intel Corp.'s Business Videoconferencing System and PictureTel Corp.'s LiveLAN were used as client systems. The diagram below depicts the simple environment we created. To reduce latency, we did not use bridges or routers. To generate audio and video traffic, we used Network Computing's Video Codec Benchmark, a VHS tape collection of clips showing various types of motion with visible frame numbers overlaid so that video transmission rates can be measured objectively.