I would suggest to check above post as it explains how you can troubleshoot VoIP related issues.
In addition please also ensure to provide Information on the currently used Software Version.
Have you contacted Portanone for support yet?
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Polycom Global Services
---------------- The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.
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