Skype for Business Online lobby feature does not work with PSTN Conferencing users

We been using Skype for Business Online meetings since the beginning of 2016 and one of the first “feature” absolutely required by our users was the ability to use regular phone lines to join the audio. When we asked them why their answers vary from “that is how I am used to do it with the other conferencing solutions” to “I have audio quality issues when using the SfB client”. It does not matter, we implemented the PSTN Conferencing “optional” license and Skype for Business meetings adoption ramped up.

One of the highly appreciated functionalities users quickly discovered is the virtual lobby. They loved the meeting organizer ability to control who gets in their meetings. The issue is that we started getting complains that when they turn the lobby on, users dialing in were unable to join the calls. Here is how reproduce the issue.

1. Create a Skype for Business meeting invite and set “These people don’t have to wait in the lobby” to “Only me, the meeting organizer”. Make sure the meeting organizer is enabled for PSTN Conferencing.
2. Try to dial into the meeting using a regular phone line (PSTN).

Dial-in users will hear the following message after they enter the Conference ID: “If you the meeting organizer press * now. Please wait for the leader to admit you to the meeting. Thank you for your patience.”

Since the meeting organizer will not receive any notification, those dial-in users will be stuck listening to lobby music unaware the meeting is going on without them.

Undocumented workaround

Despite what is documented at https://support.office.com/en-us/article/Decide-who-has-to-wait-in-the-lobby-to-get-in-to-a-Skype-for-Business-meeting-c6f26fc7-1f22-41b5-a775-33141e44d7f4, using any option other than “Only me, the meeting organizer” will allow dial in users to get in. So, setting “These people don’t have to wait in the lobby” to “People I invite from my company” or “Anyone from my organization” will enable the virtual lobby for users joining the Skype for Business meeting using the client and at the same time allow dial-in users to get in directly bypassing the lobby.

Summary of the “These people don’t have to wait in the lobby” setting impact.

Expected behavior

The workaround described above does not provide the expected behavior rather just allow PSTN callers to get into the call directly bypassing the lobby: SfB Meeting organizers should receive a notification that dial-in users are waiting on the virtual lobby and be able to admit them (or not) in the same way it works for users with the SfB client.