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Overview
This test case simulates a primary call-center or unified communications workflow. It validates that a zTC device running SnapOS can deliver a high-quality, stable voice-over-IP (VoIP) experience using a standard USB headset within a Citrix virtual desktop session.
The test focuses on ensuring Citrix High-Definition Experience (HDX) is functioning correctly by offloading audio processing to the zTC thin client. For organizations deploying softphones, passing this test is critical for user productivity and customer satisfaction.
zTC/zMAN Configuration
This section covers the necessary prerequisite of installing server certificates, followed by creating and applying the connection profiles to the zTC thin client.
Part A: Certificate Deployment (Required Prerequisite)
To launch a secure Citrix remote session, the server certificate must be installed on the zTC. Choose one of the following methods.
Method 1: Centralized Deployment via zMAN (Recommended for Managed Fleets)
This method uses zMAN Director to upload a certificate once and deploy it to many devices.
- Upload Certificate to Repository:
- Log into the zMAN Director UI.
- Navigate to Repository Management -> Files.
- Click to upload a new file and the “Upload File” dialog will appear.
- Enter a Name (e.g., Citrix Root CA) and Description for the certificate.
- Select Certificate as the File Type and click Choose File.
- Browse to your certificate file (supported formats include .cer, .pem, .crt, .p12, etc.) and click ADD.
- Deploy Certificate to zTC:
- Navigate to Device Settings -> Certificate Deployment.
- The page will list certificates that have been uploaded to the repository.
- Locate the certificate you just uploaded and click the Apply button in its row.
- Select the target zTC device(s) or group(s) and confirm the deployment.
Method 2: Local Installation on zTC (For Unmanaged Devices or Single Tests)
There are two ways to install certificate locally
- USB
- FTP
1.This method installs a certificate directly on a single zTC device from a USB drive.
- Prepare USB Drive: Copy the required server certificate file onto a USB flash drive.
- Open Certificate Installer on zTC:
- Insert the USB drive into the zTC device.
- On the zTC desktop, navigate to the Start menu -> Applications -> Certificate Installer.
- Install the Certificate:
- In the Certificate Installer window, click the add (+) button.
- Ensure the Browse from this Device option is checked.
- Click the folder icon next to File Path to open the file browser.
- Navigate to your USB drive and select the certificate file.
- Click Install to apply the certificate to the SnapOS trust store.
2. This method installs a certificate directly on a single zTC device from FTP
- Copy the required server certificate file onto a USB flash drive.
- Open Certificate Installer on zTC:
- On the zTC desktop, navigate to the Start menu -> Applications -> Certificate Installer.
- Install the Certificate:
- In the Certificate Installer window, click the add (+) button.
- Enter the ftp server details and certificate path.
- Click Install to apply the certificate to the SnapOS .
Part B: zMAN Director Configuration
- Create a Citrix Profile:
- Navigate to Device Settings -> Profiles.
- Click ADD PROFILE.
- In the “Add Profile” window, enter a descriptive Name (e.g., CallCenter_Citrix_VDI), select CITRIX as the Protocol, and enter the Host or IP of your Citrix server.
- Click ADD to save the profile.
- Apply Profile and Settings:
- Navigate to Device Management -> zTC Clients -> LIST.
- Select your target zTC device(s) and apply the CallCenter_Citrix_VDI profile .Applying profiles creates a task that can be monitored for completion.
3rd Party Setup (Citrix Environment)
- Install Citrix VDA: Ensure your master virtual desktop image (e.g., Windows 10/11) has the Citrix Virtual Delivery Agent (VDA) installed.
- Install Softphone Client: Install the target softphone application (e.g., Microsoft Teams, Cisco Jabber) on the master image.
- Ensure HDX Optimization: Ensure the VDA version and Citrix policies are configured to optimize Real-Time Audio-Video (RTAV). For Microsoft Teams, this is typically enabled by default in recent VDA versions.
- Publish Desktop: Provision a machine catalog and delivery group in Citrix Studio to publish the desktop to your test user account.
Execution
- Connect Hardware: Plug a USB headset into the zTC. USB headsets take precedence over the 3.5 mm audio jack.
- Boot and Launch: Power on the zTC and double-click the Citrix Workspace icon on the desktop.
- Login to Citrix: Enter your server address and credentials when prompted.
- Launch Session: Double-click the desired virtual desktop or application.
- Verify Device in VDI: In the virtual desktop, open your softphone’s audio settings and confirm it lists “Citrix HDX Audio” or a similar optimized device.
- Place a Call: Initiate a test call.
- Test In-Call Functions: Test the headset’s physical mute and volume buttons and perform other tasks in the VDI to check for audio disruption.
- Test Stability: Maintain the call for at least 5 minutes.
- Test Hot-Plug: Unplug and then reconnect the USB headset mid-call.
- End Call: Terminate the call and log out of the Citrix session.
Verification
This section defines the pass/fail criteria for the test.
- Audio Quality (Pass/Fail):
- PASS: Audio is clear and understandable in both directions with no noticeable echo, clipping, or “robotic” sounds. Latency is minimal.
- FAIL: Audio is choppy, delayed, distorted, or drops out.
- Headset Control Integration (Pass/Fail):
- PASS: The physical mute and volume buttons on the headset work instantly and correctly control the softphone application.
- FAIL: The physical buttons do not work, are delayed, or do not sync with the application’s status.
- Optimization Status (Pass/Fail):
- PASS: The Citrix session correctly uses optimized audio redirection, which is enabled by default in SnapOS for Citrix remote sessions. The audio device appears in the VDI as an HDX-optimized device.