Use a toll-free conference number.
Outside callers have several options that should allow them to join a Skype for Business conference toll-free:
Callers without the Skype for Business client installed should be able to click the "Join Skype for Business meeting" link in the meeting invite and use the Skype for Business Web App to participate in the meeting. The only required software needed is a web browser and a plugin.Toll-free dial-in
Each Skype for Business meeting invite should include a toll-free number that will allow callers to enter the conference toll-free. Callers will be limited to audio, and not able to see any video portions of the conference. On campus users and those in the local calling area should NOT use the toll-free number. Please use the local number provided in the meeting details instead.
A Skype for Business enabled user can invite outside callers to an impromptu meeting using the following instructions: