Windows Server enables multi-user remote desktop connections through two methods: default mode, supporting up to two sessions, and multi-user remote desktop mode, which allows multiple user sessions by using Remote Desktop Services (RDS) configuration. The latter method satisfies various requirements of multi-user remote desktop connection across different scenarios.
Working modes
Mode 1: Default mode
By default, Windows Server supports remote desktop connections through Remote Desktop Protocol (RDP) for up to two concurrent users without purchasing any RDS Client Access Licenses (CALs). A user can initiate only one RDP session at a time. If a new session begins while another is active, the existing session will be disconnected. To create additional users for remote connections, see Add logon users to a Windows instance.
Mode 2: Multi-user remote desktop mode
To support an unlimited number of users for simultaneous remote desktop access, RDS must be installed and configured on the instance.
Following RDS installation, a 120-day free trial is available, during which an unlimited number of remote desktop sessions are temporarily supported. Once the free trial period expires, RDS CALs must be purchased and configured for authorization. Otherwise, remote connections will be blocked with the error: "The remote session was disconnected because there are no Remote Desktop License Servers available to provide a license."
Alibaba Cloud Elastic Compute Service (ECS) does not supply RDS CALs. You need to purchase from Microsoft and configure them separately. For more information, see Apply for a license for authorizing multi-user sessions and activate a Windows ECS instance. RDS CALs offer two licensing modes to suit your needs:
Per Device licensing mode: Licenses are assigned per device, requiring a separate CAL for each device accessing the server. This mode is ideal for environments with few devices or shared devices, such as fixed offices or workstations.
Per User licensing mode: Licenses are assigned per user, allowing each user to use a single CAL regardless of the number of devices used. This mode is suitable for scenarios with a consistent user count but multiple devices, such as remote work or frequent device switching.
Use cases
A development department within a company uses an ECS instance with Windows Server to operate internal design software and store data. Employees require remote server access for collaborative work.
Default mode
Initially, the default mode of Windows Server could only support two remote connections at once, which was insufficient for the department's daily needs.
Configure RDS
After a technical engineer configured RDS, all employees were able to connect to the desktop simultaneously. For more information, see Enable multiple users to log on to a Windows ECS instance.
Encounter remote session interruption issue
Eventually, employees encountered an error stating "The remote session was disconnected because there are no Remote Desktop License Servers available to provide a license" due to the expiration of the 120-day free trial period.
Problem resolution
The company resolved the issue by purchasing 20 user-based RDS CALs and completing the activation configuration, allowing employees to resume normal Remote Desktop connections. For more information, see Apply for a license for authorizing multi-user sessions and activate a Windows ECS instance.
If up to two remote sessions can meet your needs, simply remove the role related to RDS and revert to the default mode at no cost. For details, see Solution 1: Remove the role related to Remote Desktop Services.
Learn more
If you need a free trial of multi-user server login, see Enable multiple users to log on to a Windows ECS instance.
If you need to configure multiple users to log on to a server simultaneously and make this situation permanent, see Apply for a license for authorizing multi-user sessions and activate a Windows ECS instance.