Removing credential prompts from Lync Web App
Lync Server version 5.0.8308.577 introduced a change that allows a Lync administrator to change the Lync Web App behaviour so that it can be used only for anonymous joining.
The default configuration for the WebService configuration is as follows:
Get-CsWebServiceConfiguration | select UseDomainAuthInLWA | fl
UseDomainAuthInLWA : True
When this default is in place you will see the ability to "Sign in if you are from the organizer's company"
If you want to remove the ability for LWA users to authenticate you can make the following configuration change.
set-CsWebServiceConfiguration -UseDomainAuthInLWA $False
Get-CsWebServiceConfiguration | select UseDomainAuthInLWA | fl
UseDomainAuthInLWA : False
Once you have made this change you will see LWA appears as follows:
Notes:
This change applies to users connecting to LWA from internally as well as externally.