Troubleshooting ICA Client Audio Issues

Summary

This document provides troubleshooting steps to help resolve audio issues with ICA sessions.

Basics of Enabling Sound Through an ICA Session

1. A sound card is required to be installed only on the client device. The server does not require a sound card as the Citrix Virtual Audio Driver will redirect the sound back to the client through the audio virtual channel.

2. Sound must be enabled on both the client and server.

On the client, check for this within the properties of the connection to see if sound is enabled.

On the server, look in Terminal Services Configuration under the Client Settings tab to see if Audio mapping is enabled/disabled.

3. Ensure the audio quality level is set the same on the server and the client. On the client, check for this within the properties of the connection to see what sound quality level is set for the desired connection. On the server, look in Terminal Services Configuration, under the ICA Settings tab. If settings on the client and server are not the same, the lower quality setting is used for the session.

The three sections below contain information obtained directly from the ICA Client and XenApp Administrators Guides. Some of the information and details are repetitive and some sections are explained in greater detail than others. This information is provided with the intent of reducing the time and effort required to resolve some of the more detailed technical and pre-sales questions with respect to ICA Audio Mapping.

Configuring Sound Options (From the ICA Win32 Client Administrators Guide)

To configure the sound options for your application set or custom ICA connections:

1. In the Program Neighborhood toolbar, click Properties. The Properties dialog box appears.

2. Click the Default Options tab to display the Options page.

From the Options page, you can configure sound:

ICA Client sound support allows a client device with a compatible sound card to play sound files on the server and present them on the local client devices sound system. Client devices can play 8- or 16-bit mono or stereo Windows .wav files at 8, 11.025, 22.5, and 44.1KHz. Audio support can be configured to use any one of the three different sound compression schemes. Each scheme provides different sound quality and bandwidth usage.

Client Audio Mapping can cause excessive load on the MetaFrame server and the network. The higher the audio quality, the more bandwidth is required to transfer the audio data. Higher quality audio uses more server CPU for processing. Three different audio quality settings are available, or Client Audio Mapping can be disabled completely. You can set audio quality on a per-connection basis but users can also set it on the client device. If the client and server audio quality settings are different, the lower of the two settings is used.

The Client Audio Quality options are:

High. This value provides the greatest audio quality but should only be used when bandwidth consumption is not a concern.

Medium. Using this value results in less bandwidth consumption than when using High. Compression of sound data provides greater bandwidth efficiency but reduces sound quality somewhat. This value is recommended for most LAN-based connections.

Low. This value offers the most efficient use of bandwidth but also decreases sound quality severely. This value is recommended for low-bandwidth connections, including most modem connections.

The server can control the amount of bandwidth used by Client Audio Mapping. Compression of sound data can be used to maximize bandwidth utilization. Audio mapping is configured per-client and per-connection in the ICA Settings dialog box.

IMPORTANT: Citrix supports sound only in the .wav format but the ICA audio channel redirects any audio that uses the "wav_out" function. This includes anything that can be controlled by the Wave Balance volume control in the expanded mixer application in Windows 95/NT. This makes the file format that the audio is packaged in somewhat irrelevant. Depending on the type of media player (Windows Media Player, WinAmp, others) used, if it converts the audio file on the server side into .wav format (to be able to use the wav_out function), the file will play correctly. The audio file decoder has to send data to the sound driver in a format that is supported by ICA Audio.

Note: MetaFrame 1.8 and MetaFrame XP include remote audio support for the Citrix ICA DOS, Web, Win16, Win32, and Mac 4.10 Clients. The following UNIX Clients also support audio mapping: HP, IBM, Solaris, and Linux.

Client Audio Mapping (From the MetaFrame 1.8/XP Administrators Guide)

Client Audio Mapping allows applications running on the server to play sounds through a sound device on the client device. DOS, See CTX819624 – Troubleshooting Steps for Common DOS Client Audio Mapping Issues, and Win16 ICA Clients require compatible sound cards. ICA Win32 Clients require any Windows-compatible sound card; the ICA Win32 Client uses standard Windows API calls for audio.

The MetaFrame XP server can control the amount of bandwidth used by Client Audio Mapping. Audio mapping is configured per-client and per-connection in the ICA Settings dialog box.

For more information about using Client Audio Mapping, see the Citrix ICA Client Administrators Guides for the clients you plan to deploy.

Configuring ICA Audio Settings (From the MetaFrame 1.8/XP Administrators Guide)

When you create or edit an ICA connection, you can use the ICA Settings button to configure audio for ICA Clients that connect to the MetaFrame XP server through that ICA connection.

When you click the ICA Settings button, the ICA Settings dialog box appears. From the drop-down list in the Client Audio Quality area, you can specify the audio quality to use for the connection. High, Medium, and Low audio quality settings are available.

High. This setting is recommended for connections only where bandwidth is plentiful and sound quality is important. This setting allows clients to play a sound file at its native data rate. Sounds at the highest quality level require about 1.3Mbpsof bandwidth to play clearly. Transmitting this amount of data can result increased CPU utilization and network congestion.

Medium. This setting is recommended for most LAN-based connections. This setting causes any sounds sent to the client to be compressed to a maximum of 64Kbps. This compression results in a moderate decrease in the quality of the sound played on the client device. The host CPU utilization can decrease compared with the non-compressed version due to the reduction in the amount of data sent across the wire.

Low. This setting is recommended for low-bandwidth connections, including most modem connections. This setting causes any sounds sent to the client to be compressed to a maximum of 16Kbps. This compression results in a significant decrease in the quality of the sound. The CPU requirements and benefits of this setting are similar to those of the Moderate setting; however, the lower data rate allows reasonable performance for a low-bandwidth connection.

Sample:

You can click the Sample button to play a brief audio sample at the selected quality setting.

Audio mapping requires that sound hardware and drivers be installed and configured correctly on the MetaFrame XP server. When audio hardware is not detected by Citrix Connection Configuration, the Sample button in the ICA Settings dialog box is not available.

Notes:

Audio mapping for ICA Clients can cause excessive load on the MetaFrame XP server and network.

High quality increases bandwidth requirements by sending
more audio data to ICA Clients. High quality audio also increases server CPU utilization.

In the Client Settings dialog box, you can disable audio for an ICA connection.

How to Avoid Data Loss with MP3 Audio Files

When using Low quality as the audio setting, the compression of the already compressed MP3 file causes some audio data loss.

Change the audio quality setting to Medium or High for the connection.

Citrix Audio Might Cause High CPU Utilization

See the following Citrix Knowledge Base articles:

CTX575854 – Internet Explorer 5.x – iexplorer.exe causing CPU 100% Utilization
CTX067748 – Microsoft ADPCM Audio Files May Cause 100% Utilization of the CPU

More Information

CTX17013 – Resolving ICA Client Audio Issues
CTX119319 – Audio does not Play in ICA Sessions from Compaq Laptops
CTX104737 – Testing Audio Input and Audio Security Policy
CTX106577 – Audio Mapping Fails with MetaFrame Presentation Server 3.0
CTX104732 – Error: Sound recorder cannot record or play back because a sound device is not installed…
CTX103644 – Sun Java applications do not play sounds within a Citrix session
CTX347193 – How to Map Audio on the Citrix ICA Unix Client
CTX105209 – The Microphone Volume Adjust Slide Bar Does Not Work in Microsoft Windows Messenger�s Audio Turning Wizard from within an ICA Session
CTX104216 – Troubleshooting and Optimizing Digital Dictation
CTX110292 – Client Audio Mapping Stops Working During an ICA Session
CTX110318 – A Policy to Deny Users Audio Capabilities does not Block Them from Hearing Audio
CTX115497 – Sound is Available for a Published Application even if Audio is Disabled
CTX118453 – ICA Queues the Session Audio for Outlook 2003 Reminders

This document applies to:

Source: Troubleshooting ICA Client Audio Issues

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