Usually I would ask you to provide the currently used software version as this would be the minimum requirement for any new post.
The SSIP7000 is neither Skype for Business certified and was never LYNC certified or compatible so your case is not a supported scenarion and should not even work.
Officially supported phones are listed => here <= and the SSIP7000 is not one of them.
As we already supplied enough information within this post to solve or diagnose the original posters issue and they never got back I will close this to prevent any other off topic posts.
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. My official "day" Job is 3rd Level support at Poly but I am unable to provide official support via the community.
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