Hello emetiB,
welcome to the Polycom Community.
Polycom manufactures these phones so they can be used with a multitude of service providers, SIP switches or even Microsoft Skype for Busines or LYNC.
You should find out what service you are using and then discuss the options with whoever installed this as without knowing this we cannot recommend anything.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Best Regards
Steffen Baier
Polycom Global Services