Background

Some organizations have on premise Skype for Business deployment without an hybrid solution. Often people have issues with presence when federating with Skype for Business Online users. 

Issues

Couple of issue's occur:

  • Users that are using Skype For Business Online cannot see the presence of the on-premises users sometimes.
This caused by the fact that the SFB Online licenses are turned on for your On-prem users in Skype. When an SFB Online only user try to federate with your On-prem users they often see that they are offline. This is caused that Skype for business Online search within Office365 first and when no match is founded that it search on DNS. Because the license is active for SFB Online and finds the unused account in Office365.

With these simple steps you can disable easily SFB Online completely and the SFB Online users will see the presence of your On-prem users within an hour.

Step 1:

Download the SFB Online PowerShell on a Windows machine https://www.microsoft.com/en-us/download/confirmation.aspx?id=39366

Step 2:

Connect with PowerShell (Admin mode) to Skype Online PS. The script below ask for your office365 credentials to connect with SFB Online PowerShell (recommend to use SFB Administrator or Global Administrator account)

Import-Module SkypeOnlineConnector
 
$userCredential = Get-Credential
$sfbSession = New-CsOnlineSession -Credential $userCredential
 
Import-PSSession $sfbSession

Step 3:

Enter the following command for the SIP Domain that needs to be deleted and is hosted on your on premises deployment:

Disable-CsOnlineSipDomain -domain <Domain Name>
 
Example: Disable-CsOnlineSipDomain -domain contonso.com


 Important
This cmdlet should not be run for domains that contain users hosted in Skype for Business Online. Any users in a sip domain that are already provisioned online will cease to function if you disable the online sip domain:

  • Their SIP addresses will be removed.
  • All contacts and meetings for these users hosted in Skype for Business Online will be deleted.
  • These users will no longer be able to login to the Skype for Business Online environment.
  • If these users use Teams, they will no longer be able to inter-operate with Skype for Business users, nor will they be able to federate with any users in other organizations.

https://docs.microsoft.com/en-us/powershell/module/skype/disable-csonlinesipdomain?view=skype-ps