Depending on the type Polycom Group Series you want to monitor, we use a different protocol for different versions
RealPresense Group 300/310/500/700 running firmware 5.X we use TELNET port 24
RealPresense Group 300/310/500/700 running firmware 6.X we use SSH port 22
If you are seeing Unsupported for the Endpoint, The issue is that you don't have telnet enabled on the older firmware for the endpoint. The Unsupported message is a side effect of the Endpoint Monitor which tries to connect on telnet and tries the next option which is SSH. Since the SSH connector requires the codec to be on 6.X we get Unsupported as the message.