July 31st 2021 is the date when Skype for Business Online (SfBO) was decommissioned. It was a good run, but we wont be missing the service. Why? Because Microsoft Teams is a more modern, cloud native service which has proven itself during difficult times with over 250 Million Monthly active users.

I wrote an article on what will happen and how you can jumpstart the process yourself at Practical 365. I also talk about what is possible when Teams is the only choice in Microsoft 365.

Skype for Business Server (SfBS) is still an option

But you should set up hybrid and consider moving your meetings to Teams. Then you will get the best of both worlds, local telephony, familiar chat in SfBS and modern meetings in Teams. The key element to a hybrid setup is that it is all federation traffic between your on-premises environment and Microsoft 365. If you have configured federation in your environment today, then you have all components in place. There are two caveats though:

1. The Edge server needs to resolve its federation DNS records, it is therefore recommended to make sure you use a public DNS server on the public network leg on the Edge server. This is because the sip domain is shared between SfBO and SfBS.
2. All Front-End servers with users need to have access to SfBO services. It is recommended to open all FQDN’s and IP address from the Front-End server to SfBO and as specified in the URLs and IP documentation for Teams and Skype. You should also open for authentication services at ID 56 and 59 in the table. This is because the Front-End servers log on SfBO when you move users online. They need to be able to authenticate and connect to the online services. It is not enough to open for just one server since it is the server where the user is homed that opens the connection.

If you want to migrate from Skype for Business Server with telephony to Teams and Direct Routing the process might include the following steps:

• Implement SfB hybrid.
• Validate PowerShell connectivity from one of the Front-End servers.
  • Required to be able to move users.
  • Remember that you must use the Teams PowerShell module as the SfBO PowerShell module has been retired
• Implement the SBC.
• Set up and validate Direct Routing.
• Move users to the cloud using the direct to Teams PowerShell switch.
  • This will move the users directly from SfBS to the Teams service.
• Assign OnlineVoiceRoutingPolicy to the migrated users-
• Finalize the migration.
• Reconfigure internal and external DNS with pointers to SfBO, such as sip.domain.com, lyncidscover.domain.com CNAME records and federation SRV records.
• Turn off the SfBSs for 1-2 weeks.
• If there are no reports of service issues, you are ready to remove all SfB users by running the Disable-CsUser cmdlet, which removes all SfB attributes from user accounts.
• Start the decommission process by clearing out the SfB servers in topology builder and publish the topology. This will clean up Active Directory for references to servers and roles.
• Replicate the Configuration Store.
• Run setup on all SfBSs and uninstall roles.
• Disjoin all servers from Active Directory.
• Decommission all SfBS servers.
• This article documents these steps