I needed to test that our (fairly ancient) Tandberg 6000 video conferencing system was working but our portable Polycom unit typically used for this purpose had failed. Trying to find a software alternative to do this is like pulling teeth as Polycom have discontinued their PVX software and replaced it with RealPresence Desktop and a suite of other software with no trial or free edition. The Polycom PVX software is the easiest way of testing our video conferencing hardware using software on the desktop but has not been updated since 2007.
Polycom PVX does still exist out there and a trial version can be downloaded from Polycom themselves (from their support site). You can also find the software to download from a few other sites such as Software Informer. With this trial edition you only get 5 minutes of video but it is enough to connect to your hardware and check everything is working. The interface is awful but it does work and the software connected to our Tandberg system fine using my computer’s webcam and mic etc.