Remote Access
RDS — Remote Desktop Services Licensing
Remote Desktop Services lets users work remotely on a server. RDS requires a special license — the RDS CAL — in addition to the Windows Server CAL. Learn when it's required, what types exist, and how to calculate costs.
When Is an RDS CAL Required?
RDS CAL IS Required
- Full desktop via RDP (work desktop)
- RemoteApp applications
- VDI (Virtual Desktop Infrastructure)
- 2+ concurrent sessions on a server
- RD Web Access / RD Gateway
RDS CAL is NOT Required
- Administrative RDP (2 sessions are free)
- Server Manager remote management
- File sharing (SMB/File Shares)
- Active Directory / DNS / DHCP services
- Print Server, WSUS, and other roles
RDS CAL Types
| Feature | RDS User CAL | RDS Device CAL |
|---|---|---|
| Assigned to | A user | A device |
| Access from | Any device | Only this device |
| Remote work | Ideal | Inefficient |
| Shift work | Inefficient | Ideal |
Complete Licensing Stack
Full RDS deployment requires 3 separate licenses:
Windows Server License
Right to run the server (Core-based)
Windows Server CAL
Right to access the server (User or Device)
RDS CAL
Right to use the Remote Desktop service (User or Device)
Calculation Example
Scenario: 30 users, 1 server (2 processors, 8 cores each).
| License | Quantity | Explanation |
|---|---|---|
| Windows Server Standard | 8 × 2-core packs | 2 × 8 = 16 cores (min. 16) |
| Windows Server User CAL | 30 | 1 per user |
| RDS User CAL | 30 | 1 per user |
RDS Farm — Multi-Server Environment
An RDS Farm is a cluster of multiple servers collectively serving RDS users. When licensing a Farm, keep in mind:
- User CAL works across the entire Farm — one CAL grants access to all servers
- Each server needs its own Windows Server license (Core-based)
- Connection Broker, Web Access, Gateway — all servers need licenses
- Device CAL is tied to a specific device and also works across the Farm
External Connector
The External Connector license is designed for external users — contractors, clients, partners. One External Connector license per server grants unlimited external user access.
- One license per server — unlimited external access
- Does not replace CAL requirements for internal users
- Cost-effective when external user count is large or unknown
- Separate WS External Connector and RDS External Connector needed
Related Articles
| Windows Server | Windows Server Core Licensing |
| Windows Server | Virtualization Rights |
| Licensing | CAL — Client Access License |