01-17-2018 09:46 AM
01-17-2018 10:13 AM - edited 01-17-2018 10:22 AMSolution
Here is the guidance that talks about all the different combinations and supported add-ons for different plans to support Audio Conferencing, Phone System and Calling Plans:
Does that cover your particular scenario?
Also @Amie McClendon check the Skype for Business Online Service Description. It seems to have a breakdown for each plan and supported add-ons in the "Skype Meeting Broadcast and Calling Plan Licensing Options" section.