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Exploring Microsoft Teams' Coexistence Modes

May 24, 2019

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Navigate the Skype for Business and Teams with Coexistence Modes

info.calltower.comhubfsMS-Teams-Workflow_Banners-4Microsoft has enabled presence for coexistence modes when those settings are used to specify collaborations for Microsoft Teams and Skype for Business end users.

Coexistence modes are settings for IT pros to use that are designed to address problems organizations may face when either shifting from Skype for Business to Teams or trying to use both solutions concurrently. Microsoft currently supports both Teams and Skype for Business as collaboration solutions, but it has announced Teams will be the client it plans to support going forward. In August, Microsoft claimed that Teams had sufficient capabilities to serve as a replacement client for the Skype for Business client for organizations.

Presence, or the ability to see collaborators, is one aspect of both Teams and Skype for Business, and it now works with coexistence modes. Coexistence mode settings determine who can call or chat with others in an organization or outside of an organization when using Teams and Skype for Business client applications.

Here's one explanation of how coexistence modes affect Teams and Skype for Business end users, per this Microsoft document:

When deployed in specific coexistence modes, Teams and Skype for Business can interoperate, enabling users to chat with and call one another, and ensuring that communications remain fluid across your organization during your upgrade journey to Teams. Coexistence modes govern interoperability. The coexistence mode of the receiver determines whether interoperability will be available.

Coexistence Modes Basics


In a nutshell, there are three basic coexistence modes settings (along with variants), according to this Microsoft document:

  • Islands Mode -- for using Teams and Skype for Business simultaneously
  • Skype for Business-Only Mode -- for organizations that want to use Skype for Business only
  • Teams-Only Mode -- for organizations that want to use teams only

Microsoft typically recommends that organizations making the transition to Teams should first start out in Islands mode, using both Teams and Skype for Business concurrently, which is the default setting. They next should rapidly shift over to Teams-only mode.

Presence for Teams and Skype for Business is based on a user's coexistence mode. If Teams mode is turned on for end users, then all users, including Skype for Business users, will see presence based on a user's activity in Teams. It's a different experience when Skype for Business-only modes, or variants, are used for end users.

Presence is independent of the application used when Islands mode is used, although the experience is a little odd for organizations using federation to collaborate with other organizations. From Teams, any other user in a federated tenent will see presence based on the user's activity in Skype for Business. Chats and calls from Teams users in a federated tenant to that Islands user will land in Skype for Business.

Microsoft's documentation explains that organizations moving to Teams can change the coexistence settings for individual end users or groups of users. User-level settings will take precedent over the organizationwide settings.

Coexistence Modes Availability


Some of the coexistence modes for Teams and Skype for Business have only become available within the last 12 months. For instance, regarding the Teams-only mode, Microsoft's documentation (dated Sept. 20, 2018) stated that "this mode started rolling out Summer 2018 and will be completed to all tenants by Fall 2018." It described variant modes, such as "Skype for Business with Teams Collaboration" and "Skype for Business with Teams Collaboration and Meetings" as "upcoming."

To learn more about Microsoft Teams and how it can impact your organization, click the logo below to sign up for a Teams Consultation with CallTower: 

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