Hello dimitri,
welcome to the Polycom Community.
The community's VoIP FAQ contains this post here:
Jan 25, 2016 Question:How many Lines can I register using Polycom phones with Lync Server / Skype for Business server ?
Resolution: You can register only one line when Lync is set as the base profile on the phone. The RealPresence Trio has Hybrid registration Feature from UC Software 5.5.2 or later. Details can be found in the Trio Admin Guide.
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
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If official support is required please check how to phone or open a case here
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The title Poly 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.
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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
