I've had a number of requests from customers wanting to automate the Join Meeting Audio dialog box that pops up when you join a Lync Online Meeting.  By default when you join an Online Meeting you are presented with the following dialog box:

This allows the user to decide where they want to take the audio for this meeting.  The option include not joining the audio session, using Lync and any connected audio device, or letting Lync call you back at any predefined number or any number of your choosing.  The options for this dialog box are all controlled in the Phones section under Options in the Lync client.

Under My phone numbers is where you can set any additional numbers that you want to use in either the call back functionality or in the call forwarding settings.  Just remember that if you don't want those phone numbers to be visible to other users, make sure to uncheck the Include in my contact card option.

The Phones section is also where you can control the behavior of the Join Meeting Audio dialog box.  You can select what you want the default option to be for taking the audio for the meeting and you can also select to show the dialog box on every meeting join or not.

This is fine for a single user, but if you want to roll out these changes to everyone in your environment you're going to need a way to script these changes.  Fortunately these values are stored in the registry on the local machine.  There are two registry keys that we're looking for that control whether the dialog box is displayed or not and where you want to take the audio for the meeting.  Both are stored in HKEY_CURRENT_USER\Software\Microsoft\Communicator.  The first registry key, AllowOverridingDeviceAtJoinTime, controls whether or not the dialog box is show at meeting join time.  It can have the following values:

  • 0=No dialog box
  • 1=Dialog box

The second registry key, JoinAudioConferenceFrom, controls where the audio for the meeting will be taken.  This key can have the following values:

  • 0=Do not join audio
  • 1=Lync
  • 2=Work
  • 3=Mobile
  • 4=Home
  • 5=Other

The important thing to remember here is that if you are going to set this key any value between 2-5, you need to make sure that the client actually has a phone number populated for the value that you choose.