Remote Desktop Services (Windows Server 2025)

Per-user RDS CALs roam with the identity — they are the right pick when users connect from multiple devices (a laptop, a home PC, a tablet, a phone). The RDS infrastructure does not pin the licence to any one endpoint; a single per-user CAL covers all of that user's devices. Per-device CALs are anchored to the endpoint — the better choice for shift workers sharing kiosks, training rooms, or factory-floor terminals where many people use a few stationary devices. Critically, you cannot mix per-user and per-device CALs on the same RD Session Host: pick one model per host (or per collection) and stick with it.

Install the Remote Desktop Licensing role on a domain member, activate it against Microsoft (online, via a web portal, or by telephone for air-gapped sites), and install the RDS CAL packs into the licence server. Each Session Host requests a licence from the licensing server on connection. Without an activated licence server, RD Session Host enters a 120-day grace period during which it serves connections; once that grace expires, no new RDS connections are accepted. The grace period exists for genuine deployment scenarios, not as a workaround — running a Session Host indefinitely in grace mode is unlicensed use.

A production RDS deployment has more roles than just Session Host. The Connection Broker distributes user sessions across hosts in a collection and reconnects users to their existing sessions after disconnect. The RD Gateway tunnels RDP over HTTPS so that remote users can connect without a VPN, with multi-factor authentication enforced via Azure MFA NPS Extension or Entra ID. RD Web Access publishes a browser portal that lists the RemoteApp programmes and full desktops a user is entitled to. None of these support roles consume additional CALs — they are licensed under the host Windows Server.

RemoteApp publishes a single application (Excel, a line-of-business app, a legacy Win32 client) so that it appears to run locally on the user's machine while actually executing on the Session Host. Full desktops give the user a complete server desktop with the start menu, taskbar and any installed applications. RemoteApp is the better experience for users who only need one or two apps; full desktops fit when users need the entire environment (engineering workstations, training labs, helpdesk fleets). Both are licensed identically — the CAL is the same.

Azure Virtual Desktop and Windows 365 do not use RDS CALs at all. AVD is licensed via Microsoft 365 E3 / E5 / F3 / A3 / A5, Windows 10 / 11 Enterprise per-user (E3 / E5), or Windows Education per-user — any of those subscriptions includes the right to use AVD with Azure compute billed separately. Windows 365 Cloud PC is licensed per user as a single SKU that bundles the compute and storage. RDS CALs apply only when you host RD Session Hosts yourself on Windows Server, on-premises or on IaaS — including Windows Server on Azure VMs that you manage as a session host pool.

Server 2025's RDS introduces GPU partitioning (GPU-P) on supported NVIDIA and AMD hardware, letting multiple sessions share a single GPU with hardware-level isolation. This dramatically reduces the cost of GPU-accelerated session hosts for CAD, GIS and AI inference workloads. The Remote Desktop Protocol gets incremental codec improvements for video and the new AV1 codec is supported end-to-end where the client also supports it, reducing bandwidth for moving content. URL redirection and clipboard policies are tighter, with new Group Policy controls for clipboard direction and file-extension allowlists.

For production estates, run at least two licence servers in the same site (the RDS role replicates licence usage between them) plus a tertiary in a DR site. Back up the RD Licensing database regularly — losing it and rebuilding the licences is a manual reconciliation with Microsoft licensing. Licences are issued per user or device and tracked in the licence server's database; per-user issuance is tracked but not strictly enforced, so accurate tracking depends on you running the RD Licensing diagnostics tool to spot over-issuance and trueing up.