The Teams upgrade configuration page allows you to configure your experience for Teams and Skype coexistence and migration. While organizations may use either or both Teams and Skype for Business, it's important to know that Microsoft has announced that the end of support for Skype for Business Online will be July 2021. If you currently administer Skype for Business Online, you should be making plans to migrate your organization to Microsoft Teams to ensure you will continue to have support.
On the Teams upgrade page, you'll find options to configure the coexistence mode and the application preferences, as shown here:
The following table lists the available options:
| Section | Option | Description |
| Coexistence mode | Coexistence mode | There are several options available: Islands: Users can use both Teams and Skype for Business apps independently. Skype for Business only: Users can receive chats and calls and schedule meetings in Skype for Business only. Skype for Business with Teams for collaboration: Users can receive chats and calls as well as schedule meetings in Skype for Business but can use Teams for document collaboration and sharing features. Skype for Business with Teams collaboration and meetings: Users can receive chats and calls in Skype for Business but use Teams for group collaboration and meeting scheduling. Teams only: Users will only use Microsoft Teams for chat, calling, meetings, presence, and collaboration. |
| Coexistence mode | Notify Skype for Business users that an upgrade to Teams is available | If this option is enabled, users will see a banner in the Skype for Business app informing them that they will soon be upgraded to Teams. |
| App preferences | Preferred app for users to join Skype for Business meetings | Select which app (Skype or Teams) will be used when joining a meeting scheduled in Skype for Business (meeting will typically have a join.lync.com or meet.lync.com address). |
| App preferences | Download the teams app in the background for Skype for Business users | If switched on, the app will be downloaded in the background. This option only takes effect if the user's coexistence mode is set to Teams or if the pending upgrade notification for the user is set to On. |
Here's a quick breakdown of the feature availability and use cases:
| Mode | Calling and Chat | Meeting Scheduling | Teams & Channels | Use Case |
|---|---|---|---|---|
| Teams Only | Teams | Teams | Yes | This is the default state for new tenants that have never had Skype configurations, as well as the final state for organizations migrating from Teams. |
| Islands | Either | Either | Yes | This is the default configuration for organizations that have had Skype for Business deployed. Users can evaluate both clients side by side. Internal chats and calls will appear in either client, depending on which client originated them. Users must always run both clients. Externally federated communications and PSTN calling will continue to be handled by Skype for Business. |
| Skype for Business with Teams collaboration and meetings | Skype for Business | Teams | Yes | This is for organizations that want to start using the "Meetings First" method of Teams adoption. The primary use case is for on-premises organizations to start using from Teams meeting functionality if they are not yet ready to move all pieces to the cloud. |
| Skype for Business With Teams collaboration | Skype for Business | Skype for Business | Yes | Similar to the previous option, only Skype is used for both calling/chat features and meetings (existing) while Teams will be used for document sharing and collaboration. This treats Teams as a "new" app and doesn't migrate any Skype functionality to Teams. |
| Skype for Business only | Skype for Business | Skype for Business | No | This is for organizations that are not ready to start using Teams. The Teams client will only be used when joining meetings scheduled by others. |
As you can see, understanding the Teams upgrade path and modes is a complex topic, so you'll want to spend time reviewing the communication modes.