Hi, I'm trying to manually configure Polycom Soundpoint IP 331 and 550 to work with our cloud hosted 3CX installation. In setting this up what I've done so far is create the extensions on the system that i want to use and using the Authentication ID and Password, and the 3CX IP I'm able to get the instrument to register and receive calls. However I'm unable to send out calls. Every time I try I just get a busy signal. I'm leaning to the configuration on the instrument itself because I'm able to send and receive perfectly using the Android app or the Windows application on the same network. The end goal is to try and migrate to using the 3CX system without having to change all our instruments. Since our organisation is relatively small - about 25 instruments - I don't mind having to configure the phones manually if it means a lower cost leading us to migrate to this system now. Any help in getting this to work would be greatly appreciated.