We are excited to announce the public preview of Remote Desktop Protocol (RDP) Multipath for Azure Virtual Desktop. This new feature is designed to enhance remote desktop connectivity and reliability without requiring configuration changes from IT admins and users. By continuously evaluating multiple network paths and dynamically switching to the most reliable one behind the scenes, this feature helps reduce the risk of disconnections and provides a more consistent user experience.
Key features
Key features of RDP Multipath include:
- Seamless integration: RDP Multipath doesn’t require changes from IT admins or users. This seamless integration means that everyone can benefit from enhanced connectivity without additional effort.
- Dynamic path management: RDP Multipath operates by evaluating multiple User Datagram Protocol (UDP) network paths simultaneously and dynamically switching the active path at runtime behind the scenes. This approach avoids single points of failure, helping to ensure that if one path fails only that path is affected while others remain operational. This helps users stay productive longer without disconnecting, and it significantly reduces the occurrence of dropouts, resulting in a more consistent and productive experience. Additionally, when multiple paths are available, the algorithm proactively selects the best-performing path even in the absence of a connection drop. This ensures consistently optimized user experience by minimizing latency and maximizing reliability.
- Insights and monitoring: When RDP Multipath is active, Azure Virtual Desktop Insights will display both the feature and the current active transport used to connect to your Cloud PC. Users will be able to see that the feature is enabled for them if they see Multipath along with the transport type currently used to connect to their Cloud PC as shown in the screenshot below. Administrators will start seeing connections with the new transport type labeled as Multipath in Azure Virtual Desktop Insights.
How does this work?
RDP Multipath finds multiple available paths using Interactive Connectivity Establishment (ICE) to create redundant connections. The active and redundant paths may consist of combinations such as UDP over Simple Traversal Underneath NAT (STUN), UDP over Relay, or multiple UDP over Relay. If one active path breaks, the system will move to the next optimized redundant path.
However, in situations where all network paths are broken, such as a host router failure or network flap within the user's network setup, users will be disconnected and then auto reconnected once network paths are available. Users relying solely on WebSocket (TCP-based) connections will not benefit from this version of RDP Multipath. Support for TCP-based connectivity scenarios will be available in future updates.
In the scenario shown in the diagram below, the primary active connection is established using UDP via STUN, ensuring low-latency communication. To enhance reliability, this connection is supplemented by two redundant UDP paths routed through a Traversal Using Relays around NAT (TURN) server. This setup provides performance and failover support, especially in constrained network environments.
How to enable this feature?
During the public preview, you can test the feature by tagging your host pool to the validation ring. By default, this feature is enabled for everyone in the validation pool, providing seamless integration and enhanced connectivity without requiring any changes from IT admins or users.
Please note RDP Multipath is rolling out in phases, available first for session hosts using UDP as the primary connection path. Currently, this feature is only available on Windows devices and Windows App and Microsoft Remote Desktop Client (MSRDC) on Windows with the latest version. Support for other platforms will follow.
To help with compatibility and optimal performance, users must be on the following minimum supported client versions:
- MSRDC: Version 1.2.6074 or later
- Windows App: Version 2.0.366.0 or later
Please update your physical endpoint to at least these versions to maintain access to all features and receive ongoing support.
Looking ahead, future updates will introduce support for multiple WebSocket connections. Additionally, users with access to UDP will be supported by both TCP and UDP paths simultaneously through RDP Multipath.
How to opt out of this feature?
If you experience any challenges such as regression from your previous connection experience, you may decide to disable the feature. To do so, you can opt out of the host pool from the validation ring. This self-help option allows you to revert to the previous configuration if necessary. For more information, see Configure a host pool as a validation environment.
Learn more
Review the documentation to learn more about RDP Multipath.
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