Configuring adaptive transport

In earlier releases, when HDXoverUDP is set to Preferred, data transport over EDT is used when possible, with fallback to TCP.

Starting with Version 4.10, and with session reliability enabled, EDT and TCP are attempted in parallel during the initial connection, session reliability reconnection, and auto client reconnect. This enhancement reduces connection time when EDT is preferred but the required underlying UDP transport is unavailable and TCP needs to be used.

By default, after fallback to TCP, adaptive transport continues to seek EDT every 5 minutes.


  • XenApp and XenDesktop 7.12 and later (required to enable the feature using Citrix Studio).
  • StoreFront 3.8.
  • IPv4 VDAs only. IPv6 and mixed IPv6 and IPv4 configurations are not supported.
  • Add firewall rules to allow inbound traffic on UDP ports 1494 and 2598 of the VDA.


TCP ports 1494 and 2598 are also required and opened automatically when you install the VDA. However, UDP ports 1494 and 2598 are not automatically opened. You must enable them.

Adaptive transport must be configured on the VDA by applying the policy before it is available for communication between the VDA and Citrix Receiver.

By default, the adaptive transport is allowed in Citrix Receiver for Windows. However, also by default, the client attempts to use adaptive transport only if the VDA is configured to Preferred in the Citrix Studio policy and if the setting has been applied on the VDA.

You can enable adaptive transport using the HDX Adaptive Transport policy setting. Set the new policy to Preferred to use adaptive transport when possible, with fallback to TCP.

To disable adaptive transport on a specific client, set the EDT options appropriately using the Citrix Receiver Group Policy Object administrative template.

To configure adaptive transport using the Citrix Receiver Group Policy Object (GPO) administrative template

The following are optional configuration steps to customize your environment. For example, you may choose to disable the feature for a particular client for security reasons.


By default, adaptive transport is disabled (Off) and TCP is always used.

  1. Open the Citrix Receiver Group Policy Object administrative template by running gpedit.msc.
  2. Under the Computer Configuration node, go to Administrative Templates > Citrix Receiver > Network routing.
  3. Set the Transport protocol for Receiver policy to Enabled.
  4. Select Communication Protocol for Citrix Receiver as required.

    • Off: Indicates that TCP is used for data transfer.
    • Preferred: Indicates that the Citrix Receiver tries to connect to the server using UDP at first and then switches to TCP as a fallback.
    • On: Indicates that the Citrix Receiver connects to the server using UDP only. There is no fallback to TCP with this option.
  5. Click Apply and OK.

  6. From a command line, run the gpupdate /force command.

Additionally, for the adaptive transport configuration to take effect, the user is required to add the Citrix Receiver Windows template files to the Policy Definitions folder. For more information on adding admx/adml template files to the local GPO, see Configuring Citrix Receiver for Windows with the Group Policy Object template.

To confirm that the policy setting has taken effect:

Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Network\UDT and verify that the key HDXOverUDP is included.

Configuring adaptive transport