HDX Transport

HDX adaptive throughput

Starting with the 2408 version, HDX adaptive throughput is supported. This feature intelligently fine-tunes the peak throughput of the ICA session by adjusting output buffers. The number of output buffers is initially set at a high value. This high value allows data to be transmitted to the client more quickly and efficiently, especially in high-latency networks.

This feature provides better interactivity, faster file transfers, smoother video playback, and a higher frame rate and resolution resulting in an enhanced user experience.

Session interactivity is constantly measured to determine whether any data streams within the ICA session adversely affect interactivity. If that occurs, the throughput is decreased to reduce the impact of the large data stream on the session and allow interactivity to recover.

Note:

This feature is enabled by default.

Adaptive transport (EDT)

Adaptive transport delivers a superior user experience on challenging long-haul connections while maintaining server scalability. This feature delivers a high-quality HDX experience on web-based platforms.

Note:

Follow the configuration steps to enable the feature.

For more information, see the Adaptive transport section in the Citrix Virtual Apps and Desktops documentation.

Requirements

The following are the requirements for using Adaptive transport:

VDA System requirements

• Virtual Delivery Agent

  ◈ Windows: currently supported version (2402 or later is recommended)

For more information, see System requirements in the Citrix Virtual Apps and Desktops documentation.

VDA Network requirements

Enable the Firewall in your internal and external network. For more information, see Network requirements in the Citrix Virtual Apps and Desktops documentation.

Gateway requirements

Citrix NetScaler Gateway

• 14.1.12.30 or later (recommended)
• 13.1.17.42 or later (13.1.52.19 or later is recommended)

For more information, see Citrix Gateway.

On-prem Citrix Gateway

For more information, see HDX enlightened data transport support in the NetScaler Gateway documentation.

Citrix Gateway service

For more information, see HDX adaptive transport with EDT support for Citrix Gateway Service in the Citrix Gateway Service documentation.

ChromeOS requirement

• The recommended Chromium version required is >=133 and later.

• Network:

  ◈ If the gateway or non-gateway with SSL VDA is used, enable the UDP Port 443 in the firewall of the client-side network.

  ◈ If non-gateway and non-SSL VDA are used, enable the UDP ports 2598 and 1494 in the firewall of the client-side network.

Known limitations in the feature

• When the ChromeOS version is 125–132, sessions might intermittently freeze.

• In the certificate chain, if an intermediate certificate is missing, then the adaptive transport feature might not work. As a workaround, set up TLS (or SSL) inspection on Chrome devices [CVADHELP-27012]

• When you use ChromeOS version 133, the Citrix Workspace app for ChromeOS might become unresponsive during the session reliability (SR) reconnect. [RFHTMCRM-15117]

Fixed issue since technical preview

• Fixed the issue related to the verification of the certificate policy extension in the certificate chain to enhance compliance. [CVADHELP-27012]

• When the VDA is powered off, the lease launch can’t start and gets stuck on the progress message “Connection leases are being resolved.” The workaround is to wait a while and then attempt to relaunch the session. [RFHTMCRM-15129]

Known issues in the feature

• For a UDP setup, if TCP is connected, then session might not go back to adaptive transport reliably. [RFHTMCRM-15116]

How to configure

You can configure the adaptive transport feature in one of the following ways:

• Google Admin Policy
• Global App Configuration service

Google Admin Policy

For managed devices and users, administrators can enable the feature using the Google Admin Policy as follows:

1. Sign in to the Google Admin Policy.
2. Go to Device management > Chrome Management > User Settings.

3. Add the following strings to the policy.txt file under the engine_settings key. You can apply this configuration to the following:

   Notes:

   You can apply this configuration on the following as well:

   • Device > Chrome > Apps and extensions > Users and browsers > Search for the extension > Policy for extensions.
   • Device > Chrome > Apps and extensions > Kiosks > Search for the extension > Policy for extensions.
   • Device > Chrome > Apps and extensions > Managed guest sessions > Search for the extension > Policy for extensions.

   The following is an example of JSON data:

   {
   "settings": {
   "Value": {
       "settings_version": "1.0",
               "engine_settings": {
                   "features": {
                       "edt": {
                           "enabled": true
                               }
                           }
                       }
                   }
               }
   }   
    

4. Save the changes.

Global App Configuration Service

Administrators can enable the feature by navigating to Workspace Configuration > App Configuration > Session Experience > Connectivity > Adaptive Transport. Select the checkbox and respective toggle button to enable the feature.

Verification steps

To check the connection over EDT or TCP:

1. Open the command prompt in the Citrix VDA session.
2. Run ctxSession -v.

3. You can identify the output for adaptive transport EDT as follows:

   • If you use SSL VDA, then follow UDP->DTLS->CGP->ICA.
   • If you use non-SSL VDA, then follow UDP->CGP->ICA.

   

Debugging and collecting Logs

In case if the adaptive transport feature isn’t working:

• Collect Citrix Workspace app for ChromeOS logs. For more information, see Client logs.

• When facing a connection issue with adaptive transport, test its functionality on the Citrix Workspace app for Windows or Mac with the same network, store URL, and user details. Testing with other Citrix Workspace app clients might help you to identify and eliminate any potential configuration or network-related issues.

• Network Traces - Collect Gateway logs.

• CDF traces on VDA side - Collect Citrix Diagnostic Facility (CDF) trace at system startup.