we recently bought and installed the Polycom IP7000. Wonderfull thing by the way. We connected it to our Siemens Openscape MX central and can call to the unit but cannot make calls from the unit. It gives a sound like the line is occupied. If have been looking for a solution on the internet but there is so much information online that I could not find the right answer.
Most likely your digitmap does not match your local requirement and above FAQ post explains how you can change this.
You could also simply delete the existing North American string.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Polycom Global Services
Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels. Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's