While all functions of the Skype for Business Phone System can be used with the Skype for Business app on the PC and mobile devices, some organizations may wish to use traditional desk phones for their phone system needs.  Skype for Business supports certain media-enabled desk phones.

The list of currently supported devices can be found at the Skype for Business Device Catalog

For more information regarding specific models and firmware versions, we recommend reviewing the following Microsoft document:

Getting phones for Skype for Business online