If we want to set-up cascading from a PictureTel 330, the conference room from which we start cascading must be empty before the cascading starts. Otherwise some clients cannot send video after the cascading has started. This behaviour has been observed using VCON MeetingPoint clients. Effectively this means that the RadVision MCU must start cascading in this case, as the PictureTel cannot start cascading from a partly occupied room. All other connection methods are propriety to the specific vendors.
Data sharing is far from standard.
Although all clients we tried are supposed to use a NetMeeting compatible data stack, we only managed to use data sharing with Windows NetMeeting. Firewalls can cause problems when setting-up H.323 calls. In our case we experienced problems with data sharing. This is due to the fact that the PictureTel sets-up the data connection itself. Always compare the specifications of the H.323 end stations used, and try various conference settings.