RDS (Remote Desktop Services)
Microsoft’s server-based desktop and application virtualisation. Before AVD and Windows 365, RDS was *the* Microsoft answer — and in many cases it still is. When is classic RDS the right choice?
What is RDS?
Remote Desktop Services (RDS) is a group of roles within Windows Server that allows several users to open sessions on one server at the same time — either as complete desktops or as published applications.
Until around 2019, RDS was the standard for Windows application virtualisation in organisations. AVD and Windows 365 shifted the focus to cloud offerings, but RDS is still supported and remains relevant for many scenarios.
RDS is not multi-session: classic RDS uses the Windows Server operating system (2019, 2022, 2025). The interface is the server shell, not Windows 11. That is an important difference from multi-session Windows on AVD, where users see a genuine Windows 11 desktop.
Former names
- Terminal Services (1998, Windows NT 4.0 Server TS Edition)
- Windows Terminal Services (Windows Server 2000/2003)
- Remote Desktop Services (seit Windows Server 2008 R2)
The RDS roles at a glance
| Role | Function | Number |
|---|---|---|
| RD Session Host | The Windows server on which user sessions run | 1 to n (depending on scale) |
| RD Connection Broker | Routes users to available session hosts, with load balancing | 1 to 2 (high availability recommended) |
| RD Web Access | A browser portal listing the available applications and desktops | 1-2 |
| RD Gateway | An HTTPS tunnel for external users (port 443) | 1-2 |
| RD Licensing | The licence server for RDS CALs | 1-2 |
| RD Virtualization Host | For VDI scenarios (VM-based, fairly rare) | Optional |
For small setups a single server with the session host role is enough; in larger environments the roles are spread across dedicated servers.
Licensing: the most complex side of RDS
RDS licensing is one of the most complicated areas in the Microsoft portfolio. Every RDS user needs several licences:
- Windows Server Lizenz — Standard or Datacenter, per core
- Windows Server CAL — per user or device
- RDS CAL — in addition to the Windows Server CAL, per user or device
- Applikations-Lizenzen — many vendors require special terminal server licences (priced above ordinary desktop licences)
Take care with hosting scenarios: running RDS for third parties — as a service provider or system house, for example — sits in its own licensing territory. Microsoft normally provides the monthly billed SPLA model for this, and passing on licences from your own volume agreement to third parties is typically not envisaged. The exact terms depend on the individual contract and change regularly — before setting this up, the licensing should be clarified with Microsoft or a licensing adviser.
RDS vs. Multi-Session Windows
RDS (Windows Server)
- OSWindows Server 2019/2022/2025
- InterfaceThe server desktop (Server Manager visible)
- Application compatibilitySome applications refuse to install
- LicencesWindows Server CAL plus RDS CAL
- AvailabilityAny platform (Azure, AWS, on-premises)
Multi-Session Windows
- OSWindows 11 Enterprise Multi-Session
- InterfaceThe Windows 11 desktop
- Application compatibility100% (as on a PC)
- LicencesIncluded with Microsoft 365 E3/E5
- AvailabilityMicrosoft Azure only
When does RDS still make sense today?
Strong candidates for RDS
- On-Prem-Setups — your own data centre, no cloud
- Smaller businesses with simple application publishing needs — one or two terminal servers suffice
- Multi-Cloud / Non-Azure — AWS, GCP, your own hosters — multi-session Windows is not available there
- Integration with oneClick or Parallels RAS — broker platforms that build on Windows Server RDSH
- Existing RDS estates — migrating to AVD is not always worth it
- Specialised industry software — some software (older SAP GUI, older DATEV versions) runs only on a server operating system
RDS is not ideal when
- Cloud-native Strategie — AVD and Windows 365 with Microsoft 365 E3/E5 are often cheaper and more modern
- Moderne Apps — Teams, OneDrive and modern UWP applications run best on Windows 11 multi-session
- Small user numbers and a need for flexibility — Windows 365 is simpler for smaller businesses
- Avoiding licensing complexity — AVD with Microsoft 365 E3 involves far fewer CALs
RDS in the DaaS landscape
DaaS Maps compares RDS-based platforms (oneClick, Parallels) with modern cloud DaaS services. For discussion of migration strategies from RDS to AVD, you will find me on LinkedIn.