
From Skype for Business to Microsoft Teams
On the Right Track
First came Office Communications Server, then the product was renamed Lync, and later Skype for Business Online – which will be discontinued at the end of July 2021. Until then, there will purportedly be no restrictions on its use. For this reason, all new Microsoft Office 365 customers started migrating to Microsoft Teams in September 2019. In this article, I show you how to migrate to Microsoft Teams.
Companies currently using Skype for Business Online can continue to add new users until it is phased out in 2021. However, as soon as Skype for Business Online is no longer available, the service's server, which in principle is still functional, will become orphaned from the Office 365 family. Administrators need to understand that the new Microsoft Teams [1] is not the next version of Skype for Business. Instead, Teams is a standalone product that offers new collaboration features and includes features from the SharePoint collaboration platform, OneDrive data management system, and Skype for Business meeting service. The right way to imagine Teams is to think of it as two products in one: a collaboration tool and a communication tool.
Teamwork Repositioned
As a collaboration product, Teams offers features similar to Slack that overlap and leverage the existing features of SharePoint, OneDrive, and the Yammer social network. Teams as a communication product offers many of the existing features of Skype for Business Server, which has always offered more possibilities than Skype for Business Online. Communication options include presence status, instant messaging, peer-to-peer calls, traditional phone calls, and audio and video conferencing. A "team" within Microsoft Teams describes a collection of people, content, and tools for different projects and outcomes within an organization. Teams can be set up so that only invited users have access or can be created as public teams, in which everyone in the organization can participate.
Teams are designed to bring together groups of people who collaborate closely to improve their productivity. Dynamic teams are possible for project-oriented tasks. Another variant is permanent teams that reflect the internal structure of a company. Conversations, files, and notes on team channels are only visible to team members.
In contrast, channels are special sections within a team that organize conversations by topics, projects, focus, or other aspects important to the team. Files that are shared on a channel and stored in SharePoint channels are places where conversations take place and where the work is actually done. Standard channels are open for conversations in which any person on a team can participate. On private channels, communication is limited to a subset of people in a team.
The teams an admin sets up can, for example, be aligned with the organizational structure (Figure 1). When migrating to Teams, companies currently using Skype for Business on-premises might need to consider several different ways in which team communication works, including the origin of the data. Larger companies might have established multiple Skype for Business pools in different countries to comply with legal requirements regarding the storage of call details, instant messaging (IM), uploaded content, and meeting recordings.

The multi-geo capabilities of Teams do not currently offer the same level of control. However, the integration of contact centers and third parties also plays a role. Companies that have integrated contact center applications into Skype for Business or have invested in third-party reporting or management tools should be aware that few or none of the existing tools will work with Teams.
Difficult Merger
The Office Communications Server/Lync/Skype for Business federation model was very easy to implement and manage and offered a huge improvement in the ability to communicate and hold meetings with users from organizations that also use Skype for Business. In practice, the federation between customers and suppliers has resulted in a significant improvement in business relationships and overall customer service. However, guest access among teams is currently difficult to manage and creates an incoherent user experience. Microsoft has said it intends to improve this in future updates.
Although similar, meetings with Teams and Skype for Business have some essential differences. Although you can set up a dedicated Skype for Business pool to create interactive meetings with up to 1,000 users, Teams' meeting size is currently limited to 250 users. However, don't confuse this feature with broadcast meetings, now dubbed "live events" in Teams, which support meetings of up to 10,000 participants. Live events are one-to-many meetings rather than interactive meetings in which participants can only join in from a web browser.
Another difference is that whereas Teams can share desktops, a specific application window, or PowerPoint slides during a meeting, you cannot annotate them as you can in Skype for Business. Also, Teams meetings can be recorded, and these recordings can be stored in the cloud. With Skype for Business, meeting recordings could only be stored locally on personal computers. Teams can also provide a transcription of the audio recording of meetings if required, and the presenter's video background can be obfuscated.
New in Teams: IP Phones
Microsoft has introduced a number of newly certified Teams IP phones. However, the company stressed that basic features will continue to be available on Skype for Business Online certified devices when a user switches to Teams with their Skype devices. Microsoft has also restructured the call queuing service for Teams. In Skype for Business, this feature was still known as "response groups." Likewise, the automatic transfer and interactive voice response (IVR) functions in Teams are based on new code. At present, though, compared with Skype for Business, Teams lacks some features for managing call queues.
When it comes to interoperability, Teams and Skype for Business do not always work together seamlessly or perfectly. If you want to support larger groups of users on both platforms over a longer period of time, be sure to test the interoperability features to eliminate potential communication and management issues in advance. Certain interoperability scenarios may result in a company minimizing the need for Teams and Skype for Business to run in parallel.
Incompatible Gateways
Teams introduces a new feature known as Direct Routing that allows existing Session Border Controllers (SBCs) to be integrated into teams. In practice, however, it should be noted that some of the SBCs and gateways already in use in the company might not be supported by Teams or might require a software upgrade. SBCs can also be linked to Skype for Business Online; however, this requires admins to provision a local Skype for Business server or integrate a special edition of Skype for Business (known as a Cloud Connector) between the SBC and the Microsoft cloud (Figure 2). This scenario is referred to as Hybrid Voice. Based on direct routing, the existing SIP trunks or standard ISDN (E1) connections in the enterprise can be integrated into Teams, as can existing phone systems and analog end devices in the company.

Microsoft recommends a local breakout (direct connection) to the Internet for every office or branch office on the network (Figure 3). The idea is to improve real-time communication in Teams. Microsoft's primary goal in terms of the network design for Teams is to minimize latency by reducing the round-trip time (RTT) from the user's network to the Microsoft Global Network (Microsoft's public network backbone that connects all Microsoft data centers and cloud application entry points). The concept of local breakouts is different from the "hub-and-spoke" network model that large enterprises have implemented for local Skype for Business use. For this reason, when migrating from Skype for Business to Teams, you need to assess the effect of network architecture changes on network operations.

Important Migration Issues
With all the arguments that Microsoft has for switching to Teams, practice has shown that, although a quick switch from Skype for Business to Teams is possible, the pitfalls of such a migration lie, as always, in the details. Sometimes the ad hoc approach works, but often enough such an approach results in chaos. The following integration questions therefore need to be an integral part of every Microsoft Teams installation:
- Have the expectations been defined (in writing)?
- Are the management's expectations for the project known?
- Has interoperability been planned properly, and are appropriate verification functions defined?
- Is it possible to pilot Teams initially with IT staff?
- Will the results from the pilot users be incorporated into improving the migration strategy?
- How can users be told what to expect and when?
- Are the results regularly measured and documented?
The planning and implementation of the above steps naturally requires time and commitment. Doing the right thing always means going the extra mile. A step-by-step migration requires more work in terms of evaluating, testing, managing, and implementing Teams, but it significantly improves the chances of achieving satisfactory results.
Migrating from Skype for Business to Teams
The effective use of Teams requires an understanding of how aspects such as the configuration of Teams and the channels it uses can be designed correctly and how messages can be communicated effectively within Teams. When migrating to Teams, users are often confused. Let me repeat: Teams is not the next version of Skype for Business. Teams offers additional features and new functionality, although Teams features can supplement and overlap the familiar Skype for Business features. If a company is already using Skype for Business and wants to introduce Teams, the following migration paths are possible: coexistence with Teams, parallel operation of both solutions, or the exclusive use of Teams.
Coexistence with Teams
Microsoft provides several coexistence or upgrade modes to facilitate the transition to Teams. Think of it as a hiking trail with several starting points and different waypoints, with all trails leading to the same destination. Typically, larger companies using all the Skype for Business features (IM/presence/voice/conferencing) will need to start at the beginning of the path and cover all the waypoints. Smaller businesses may be able to skip one waypoint or another during their journey.
Regardless of where the journey begins, each upgrade mode requires a number of prerequisites:
- A fully functional Office 365 with the appropriate licenses for operating teams
- An active hybrid connection with Office 365 when using Skype for Business on-premises
- Skype for Business Server 2019 or Skype for Business Server 2015 with cumulative update (CU) 8
Temporary Islands Mode
Unfortunately, Islands mode does not mean a permanent tropical holiday where you can enjoy cold drinks. Instead, it is the default setting for companies that want to activate Teams. In this mode, all features and functions of Teams can be used, and it is therefore best suited for all Proof of Concept (PoC) testing.
However, Islands mode is not intended as a long-term solution because the end user is expected to use Skype for Business and Teams side by side. As the name suggests, teams in this mode are on an island: Teams and Skype for Business don't really know about each other's existence. Users can create content on the team channels, hold meetings, and chat with other users while using the Teams client.
This mode provides no actual coexistence with Skype for Business. For example, the presence status between the two clients cannot be synchronized. This might work in smaller companies, but it is certainly a problem for larger companies. Lessons to learn:
- Synchronizing presence data between Skype for Business and Teams is not possible. If a busy status is displayed in Teams, Skype for Business users do not see this status; instead, they only see the Skype for Business presence status.
- Messages from one-to-one conversations that users send in Islands mode are delivered according to the sending client. Therefore, if Eve tries to reach Adam via Skype for Business and Adam only runs Teams, Eve will receive notification of a "missed IM message."
Islands mode is therefore typically used for testing Teams and trying out its functions. In practice, companies should try to minimize the time spent in this mode and switch users to a coexistence mode, once available, to minimize negative effects on the user experience.
After a company has successfully tested a pilot installation of Teams, deployment for production use can begin. To ease the transition, users should be transferred to one of the upgrade or coexistence modes. Each of these modes provides predictable behavior when migrating from Skype for Business to Teams. In the next sections of this article, I assume that all Skype for Business workloads are in use.
Skype for Business Only
All users you switch to Skype for Business only mode will continue to be able to use Skype for Business in the usual way. Although this might not sound like too much fun, it does serve a useful purpose en route to Teams. If, for some reason, a group of users needs to stay with Skype for Business while the rest of the company starts using Teams, you can assign this mode to those users. These users will not be able to use Teams. However, and this is important, they will coexist with their colleagues who run Teams and who have been assigned a different coexistence mode. This coexistence mode ensures that the Skype for Business and Teams clients recognize each other and route instant messages and calls to the right application for the users.
If special business functions are required and some users need to stay with Skype for Business, this mode provides the necessary communication functions. Users in Skype for Business only mode can still participate in Teams meetings to which they are invited by internal or external users.
Skype for Business with Teams Collaboration
Skype for Business with Teams collaboration mode lets users take advantage of the benefits of Teams collaboration and gives users access to teams and channels while using the Skype for Business client for the IM and presence features, to make calls, and to join meetings. In this mode, the Teams and Skype for Business clients work side by side to provide communication and collaboration capabilities. Users cannot schedule team meetings, but they can start channel meetings as needed.
This mode is suitable for larger companies that have strict IT control mechanisms or methodical change processes. On the technical side, a company might have a third-party video infrastructure or other Skype for Business-integrated applications that are not yet ready for Teams migration.
Skype for Business with Teams Collaboration and Meetings
The Skype for Business with Teams collaboration and meetings mode builds on the coexistence mode described above and adds meeting functionality to Teams. In this mode, a user no longer schedules, and in fact is prevented from scheduling, meetings in Skype for Business. Instead, the user receives an Outlook add-in for Teams. All meetings that were scheduled before the switch are automatically transferred to Teams by the meeting migration service.
Users in this mode can still participate in Skype for Business meetings set up by colleagues in the migration islands of systems running Skype for Business with Teams collaboration. Users can join these meetings using the Skype for Business client (if still installed) or through their browser with the Skype for Business web application. Users in this mode have their home directory either on a Skype for Business server or on-premises in Skype for Business Online.
This mode is suitable for companies that already conduct their meetings in Teams but do not yet want to implement their enterprise voice applications there. These companies typically have a problem with third-party video application interoperability. The meeting features in Teams offer new capabilities, such as changing the focus of video backgrounds, recording meetings in the cloud, and automated transcription services to convert voice to text for audio in meetings.
Teams Only
In Teams only mode, users assigned this policy will only use the Teams client. With this change, all users working on a Skype for Business server (on-premises) will need to move to Skype for Business Online. Even if the user is not using the Skype for Business client, the user object must exist in Skype for Business Online at that time. In other words, Teams only means that a user's Skype for Business object no longer exists on the Skype for Business server. If a user has already been set up in Skype for Business Online, then nothing more needs to be done in the Teams only mode.
At this point, users run their 1:1 chats and enterprise voice (if applicable) in the Teams client. For instant messaging and voice calls, interoperability between Teams only users and the following modes is guaranteed:
- Skype for Business only
- Skype for Business with Teams collaboration
- Skype for Business with Teams collaboration and meetings
- Teams only
This mode is suitable for users who want to use the full scope of a Teams client and removes any reliance on third-party interoperability for video. Additionally, all voice features – such as response groups, auto-attendant, toll-free numbers, contact centers, and other integrated software applications – have moved from Skype for Business to Teams.
After the Upgrade
Once you have completed part of the migration to Teams, it makes sense to take some time to evaluate whether you have achieved the goals defined in the planning phase. It may be necessary subsequently to draw up a plan to fulfil all the targets that have not yet been met. You will want to pay particular attention to the network team. It is essential to ensure that the planned requirements for the network match the actual effect after the upgrade.
Conclusions
Teams is a new product with various collaboration and communication functions, giving companies a wide range of options. You can ignore Teams. After all, just because it is a new tool on the market does not mean you have to use it. On the other hand, you can roll out Teams to provide new collaboration features and still keep Skype for Business for communication, which might require an upgrade to Skype for Business Server 2019.
A third option is for companies to set up teams for collaboration and arrange for some user groups to communicate in Teams, while leaving other user groups in Skype for Business. Alternatively, Teams can be made available for collaboration to facilitate the transition to Teams' meeting functionality while Skype for Business remains the primary voice call platform. The way forward that still remains is to complete the transition to collaboration and communication with Teams in multiple steps.