Choosing the Right Coexistence Mode: Skype for Business to Teams Migration
Upgrading from Skype for Business to Microsoft Teams isn’t just about flipping a switch. If your organization relies on multiple workloads in Skype for Business—such as Audio/Video Conferencing, Dial-in Conferencing, Enterprise Voice, Persistent Chat, and Messaging—you need a transition path that avoids service disruptions while giving users a chance to explore Teams.
One common challenge is this:
How do you let users evaluate Microsoft Teams while still keeping PSTN calling in Skype for Business?
Understanding Coexistence Modes
Microsoft provides several coexistence modes to help organizations transition smoothly:
- Islands Mode
Both Teams and Skype for Business are fully available. Users can chat, call, and meet in either client. This often creates confusion since users may not know which platform to use. - Skype for Business with Teams Collaboration
Skype for Business continues to handle calling and meetings, while Teams is enabled for chat and collaboration. This lets users try Teams without losing critical telephony services. - Skype for Business Only
Teams is disabled, and all workloads remain in Skype for Business. This is typically a short-term or fallback option. - Meetings First
Meetings move to Teams, but Skype for Business remains in place for PSTN voice and chat.
Best Option for Evaluating Teams with PSTN Calling
If your goal is to let users evaluate Teams while keeping PSTN calling in Skype for Business, the right coexistence mode is:
👉 Skype for Business with Teams Collaboration
This approach ensures:
- PSTN voice services remain uninterrupted in Skype for Business.
- Users can explore Teams chat, collaboration, and channels without confusion.
- A smoother migration path by introducing Teams gradually.
Why Not the Other Modes?
- Islands Mode: Causes user confusion, since chat and calls may arrive in either app.
- Skype for Business Only: Blocks Teams, preventing evaluation.
- Meetings First: Good for moving meetings to Teams, but doesn’t focus on chat/collaboration testing.
✅ Tip for Admins: Start with “Skype for Business with Teams Collaboration” when piloting Teams. Once users are comfortable, you can phase in Meetings First and eventually move to Teams Only mode for a complete migration.
