FAQ

What are the first things to look for when a connection between client and server fails?

Here are some ways to resolve the connection failure:

• Verify that the IP address is correct for server.

• Verify the syntax for the IP is correct if using command-line format. For example, a server at IP 10.0.0.6 would be specified as -s 10.0.0.6.

• Check the client and server logs for matched versions.

• Verify that the CXR server is running.

• Verify that the app storage permissions are enabled for the CXR app on Android clients.

• If using config file for command-line/launch options, verify the file CloudXRLaunchOptions.txt exists in the proper location (see Command-Line Options).

What GPUs are supported on CloudXR Server?

VR-ready GPUs from the Pascal™ and later architectures are supported. If a laptop is used as a server, ensure that both SteamVR and the applications are running on the NVIDIA GPU. Streaming from an iGPU is not supported.

What GPUs are supported on the Windows CloudXR client?

All GPUs that are based on the NVIDIA Pascal™ and later architectures are supported. On a laptop client, ensure that both SteamVR and the CloudXR Client application are running on the NVIDIA GPU. Streaming to an iGPU is not supported.

Does the CloudXR server driver support virtual GPUs (vGPUs)?

Yes, assuming that the vGPU QvDWS driver is associated with a Windows or Windows Server virtual machine.

With CloudXR, can you use vGPU to run multiple VR users on one GPU?

You can run multiple virtual machines that support XR workloads with NVIDIA QvDWS.  The performance of any GPU with multiple users is highly application dependent, but for average XR workloads, use the following table as a guide:

GPU Model	# Users	vGPU License Types	Installation Types
P4000	1	N/A	Workstation / PC
P5000	1	N/A	Workstation / PC
P6000	1	N/A	Workstation / PC
GP100	1	N/A	Workstation / PC
P100	1	RTX Virtual Workstation	Virtualised / Cloud Hosted
P40	1	RTX Virtual Workstation	Virtualised / Cloud Hosted
GV100	1	N/A	Workstation / PC
V100	2	RTX Virtual Workstation	Virtualised / Cloud Hosted
T4	1	RTX Virtual Workstation	Virtualised / Cloud Hosted
RTX4000	1	N/A	Workstation / PC
RTX5000	1	N/A	Workstation / PC
RTX6000	1	N/A	Workstation / PC
RTX6000	2	RTX Virtual Workstation	Virtualised / Cloud Hosted
RTX6000 Passive	2	RTX Virtual Workstation	Virtualised / Cloud Hosted
RTX8000	1	N/A	Workstation / PC
RTX8000	2	RTX Virtual Workstation	Virtualised / Cloud Hosted
RTX8000 Passive	2	RTX Virtual Workstation	Virtualised / Cloud Hosted
A6000	1	N/A	Workstation / PC
A6000	2	RTX Virtual Workstation	Virtualised / Cloud Hosted
A40	2	RTX Virtual Workstation	Virtualised / Cloud Hosted

Which operating systems are supported?

The NVIDIA CloudXR server and client support all Microsoft Windows 10 and later releases, including the Windows 10 Server and the Windows 2019 Server. The client also supports Windows 7.

Are there any restrictions on the GPU driver?

The recommended driver is version 440.97 or later. The general recommendation to use any NVIDIA product is to upgrade to the latest driver. NVIDIA CloudXR does not require the same driver version on the client and server.

What headsets are officially supported?

CloudXR has been tested with HTC Vive, HTC Vive Pro, Valve Index for the Windows client, and HTC VIVE Focus 3, Oculus Quest, and Quest 2 for the Android client.

Which types of apps are supported?

NVIDIA CloudXR supports any OpenVR-compatible application.

Is protected content supported?

Currently, NVIDIA CloudXR does not support protected content.

What are the restrictions on redistribution of the SDK binary files?

For details about licensing, see the EULA that is packaged with the SDK.

What are the Steam and SteamVR requirements?

Here are the requirements:

• Steam is required with the consumer version of SteamVR.

• CloudXR does not require the same version of SteamVR on the client and the server.

• The release and the beta versions of SteamVR are supported.

• SteamVR Enterprise is supported, and Steam is not required to be installed with this version.

Do I need to reinstall the client if the server is reinstalled?

No, but the client and server need to be the same NVIDIA CloudXR SDK version.

Can multiple NVIDIA CloudXR SDK clients be connected to an NVIDIA CloudXR SDK server driver or an NVIDIA CloudXR client be connected to multiple servers simultaneously?

No. The relationship between an NVIDIA CloudXR SDK client and an NVIDIA CloudXR SDK server driver is a one-to-one relationship.

Does NVIDIA CloudXR work over wireless networks?

Yes, for wireless networks with limited download speeds, and many potential sources of interference, the quality of a remote VR session might be impaired. For Wi-Fi wireless networks, we recommend 5GHz routers with beam forming for a more reliable connection.

What are the network speed requirements for the connection?

For a Wi-Fi connection, the client requires download speeds of at least 50 Mbps, ideally at least 60 Mbps. Similarly, the server requires upload speeds of at least 50 Mbps, ideally at least 60 Mbps.

Which ports are required for the client and the server?

The CloudXR installer will open the ports that are associated with CloudXR in the Windows Firewall. If the connection cannot be established, turn Windows Firewall off temporarily and try again.

Here are the ports that are used by the client and server:

Server		Client
Control	47999	Control	49006
Audio	48000	Audio	49003
Video	47998, 48005	Video	49005, 50000-55000
Microphone	48002	Microphone	49004
RTSP	48010	RTSP	49007

Note

All ports needed are UDP, except RTSP, which is TCP.

The RTSP stream is used to establish the connection. Once this is done the individual streams transmit data with RSP.

How are the individual streams for each eye synchronized?

The frames for the eye streams are sent with a frame number, which the client uses to synchronize the frames.

Why am I facing connection issues even though the firewalls are turned off and/or the required ports are open?

One possible issue is compatibility problems with Remote Desktop Software. Otherwise, look at other installed network applications on the client or server that might be consuming or blocking ports.

Does the OpenVR application need to be modified to work with CloudXR for VR?

If the application queries the device parameters via OpenVR, and does not hard-code headset parameters, it will work without modifications. CloudXR will forward the client device specifications, such as a resolution, a field of view, and the refresh rate.

Does CloudXR support client-server authentication?

This is not currently supported, you would need to implement authentication outside of the CloudXR connection.

Does CloudXR encrypt data streams?

CloudXR does not currently encrypt any streams, including setup, input, audio, and video.

What other command-line options are available for the clients?

See Command-Line Options for more information.

How do I capture ETL streaming traces so that the CloudXR support team can analyze them?

See ETL Traces for information about how to capture ETL traces.

Why is the order of launching CloudXR important?

The order is required because the server does not have the necessary information to feed to the game until after the connection is made unless it has been pre-configured on the server. This situation is like starting an app without first plugging in your virtual reality (VR) device.

The order is:

1. Start SteamVR on the server.

2. Start the CloudXR client to make the connection.

3. Start the game/app on the server.

What if I am not hearing any audio from the server when using the Windows client?

One possible issue might be that there are multiple audio outputs on the client system.

• In this case, ensure that the headset setting is being used. This setting can be viewed/changed by left clicking the sound control in the system tray and selecting the desired output in the list just above the volume control.
• Also, sometimes, it helps to have a real audio output device, speakers, or headphones attached to the server.
• If the Graphics driver is updated, ensure that that a CloudXR SW reinstall is completed after this update with the audio capture driver checkbox selected.

Another possibility is that there are no audio facilities on the server, such as there are for a cloud server. In this case you can select the NvVAD device to provide audio capture for sending to the client. This should be a selection in the audio popup in the lower right corner of the task bar.

What if I am not hearing any audio from the server?

Ensure that the Audio Capture driver is installed on the server as part of the CloudXR installation. See Figure 2‑1 for more information.

How do I get access to the Steam VR menu while streaming?

While streaming, to access the Steam VR menu, complete one of the following tasks:

• For Quest, click the left controller menu button.

• For Vive and FocusPlus, click the left menu button.

• For Index, click the left B button.

With CloudXR, does a dual GPU system work for the server or the client?

For the server, the overlay window is rendered on the iGPU, so a MSHybrid server is not supported. For the client, the decode must occur on the dGPU, and in this case, a dual GPU system is supported.

How can I determine the ping time from a stand-alone headset to the CloudXR server?

With the stand-alone headset that is connected to a Windows system, run the following ADB command:

adb.exe shell ping <Server IRL>

Will my CloudXR server properly stream to clients while a VR device is connected to it?

For the NVIDIA CloudXR server driver to be activated, before you start SteamVR, ensure that the VR device, such as Vive, is disconnected from the system.

Why does my client microphone content not stream to the server?

If you are on an Android device, make sure that microphone permission has been granted to the application.

What is another possible reason I can’t connect to the Server with my client?

In some rare cases, CloudXR, a SteamVR add-on, might get disabled, which causes the CloudXR server to not function.

To verify that CloudXR is enabled:

1. In the SteamVR menu, select Settings > Advanced and select Manage Add-ons.

2. Ensure that CloudXRRemoteHMD is set to on and that only one item like this is present.

Why am I getting a green video stream on the client?

This can be caused by any application on the server that prevents capture of the source video. One specific cause may be if you are remotely controlling your server – for more details, see Remote Desktop Software. It also can be caused by certain screen recording applications.

Why does Gear VR no longer work with CloudXR?

CloudXR is now using Oculus Mobile SDK 18.0 (API 1.35), which no longer supports Gear VR. Oculus discontinued support for GearVR in API 1.27.

Does CloudXR support arm-64?

Yes, as of Release 2.0, release arm-64-v8 is supported.

Are CloudXR server/client binaries compatible with the earlier versions?

No, these server/client binaries are not compatible. We recommended that you have the exact matching client and server versions.

Are there are any restrictions that would prevent CXR from running in a Network Address Translation (NAT) or Network Address Port Translation (NAPT) environment ? Is port forwarding supported?

No, there are no restrictions. If you make sure that the ports are forwarded, it should work.

Is there a way to proxy the network traffic through Citrix virtual channels when a direct connection between the client and server is needed?

No, currently CloudXR will not work with Citrix VCs.

Is there a need for a UE4 plugin?

After you install the CloudXR server driver, you can use the existing OpenVR plugin. CloudXR just appears as a regular headset. There is no need to create an Unreal Engine plugin to use CloudXR because CloudXR works transparently with the existing OpenVR support that is built into the engine. You should be able to get it up and running without having to modify any UE4 code.

What is the maximum resolution to use CloudXR on Android? If I have a device with an 8K decoder, can I play 8K content in the CloudXR?

For the CloudXR library, you can specify the maximum resolution when you create the receiver instance. For the CloudXR sample apps, the display resolution * 1.2x is used as max res and you can override that from the config file. Currently, the resolution is limited to 4k.

Is there a current bandwidth cap in CXR for video?

The cap is 50 Mbps per eye, so 100 Mbps total.

Is WebAR supported with CXR?

Currently, WebAR is not supported.

Is eye-tracking supported with CXR?

No, currently eye-tracking is not supported.

How is the CloudXR server add-on added to SteamVR? How can I add it back if it gets removed?

During CloudXR installation, the CloudXR server add-on is added to SteamVR with the vrpathreg.exe utility that is bundled with Steam. You can read it by manually running the command.

<Steam-install-dir>\steamapps\common\SteamVR\bin\win64\vrpathreg.exe
       adddriver "<CloudXR-install-dir>\VRDriver\CloudXRRemoteHMD"

Why does the SteamVR headset icon not show the “CXR” letters when connecting the headset?

This is because the SteamVR cache does not realize the icons have been updated. You can delete the cached icons by navigating to C:\Program Files\NVIDIA Corporation\CloudXR\VRdriver\CloudXRRemoteHMD\resources\icons and deleting the files with hex values in their names.

Can CloudXR stream Stereo RGBA for devices that support that?

No, currently CloudXR can only stream Stereo in raw RGB. The only RGBA support is for Mono AR streams.

Does CloudXR have any support for scene Depth?

No, currently CloudXR Server does not support streaming Depth surfaces, and the Client samples do not show how to capture AR Depth information.

Why was HoloLens 2 removed

The CloudXR 3.0 SDK includes optimizations to the API that allow better performance for clients. This change requires significant effort to validate the highest performance on each hardware device. We were not satisfied with the end-performance on HoloLens devices. Instead of releasing a client that does not accurately reflect the optimizations made within CloudXR 3.0, we’ve made the decision to remove support for HoloLens until the HoloLens client can be returned to the highest level of standards users expect. We realize this may be difficult for users who have been experimenting with HoloLens and CloudXR but believe this is the best decision in the long run.

When will you return HoloLens support in the future? What about CloudXR 3.X?

We will return support for HoloLens once we believe the client achieves the high level of standards we expect for CloudXR clients. We do not have a timeline for when this will be achieved but continue to evaluate performance based on customer demands and requirements.

What should I do now if I am using HoloLens for my project?

If using the HoloLens for existing projects, we suggest you remain on 2.1 and not upgrade to 3.0.

What does this mean for other headset devices in the future?

As an SDK, CloudXR strives to achieve the highest level of standards and undergoes rigorous testing on the leading hardware devices. As hardware updates and new versions/devices become available, we continue to validate CloudXR based on the latest hardware enterprises leverage.