The same is experienced for clients that are connected to parts of the Internet that do not have enough bandwidth. Measured delay of the audio and video source was about one second, which is not to disturbing and comparable to intercontinental POTS phone calls. Overall video switching was good although an image freeze, lasting a few seconds, occurred as a person entered or left the conference. When a PictureTel MCU was invited to the RADVision MCU before any participant was registered at that MCU errors occurred. The MCUs seemed to have problems sending the video signal.
Recommendations Always use one ore more gatekeepers for a cascading set-up.
Always compare the specifications of the MCUs and H.323 end stations used, and try various conference settings. For example some older clients cannot send more than 15 frames per second. All MCUs should at least have the same conference settings. Even if some end stations are used that cannot keep up with these settings. Try initiating the cascade from all MCUs used.