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A new feature is available for Windows Media Services 9 Series that lets a server administrator disable Forward Error Correction (FEC) for multicast streams

Article ID: 920140

Article Last Modified on 3/23/2007

APPLIES TO

Microsoft Windows Media Services 9 Series

Warning This article contains information about editing the namespace. Before you edit the namespace, verify that you have a backup copy that you can restore if a problem occurs. If you edit the namespace incorrectly, you can cause serious problems that may require you to reinstall any product that uses the namespace. Microsoft cannot guarantee that problems that result if you incorrectly edit the namespace can be solved. Edit the namespace at your own risk.

INTRODUCTION

This article discusses a software update that is available for Microsoft Windows Media Services 9 Series. This software update adds a feature that lets a server administrator disable Forward Error Correction (FEC) for multicast streams.

MORE INFORMATION

During a Windows Media multicast broadcast, the client does not have a direct connection with the server. To maintain the quality of the stream during a multicast, the server automatically adds error correction packets to the stream. If a packet is lost, the client can rebuild the lost packet through the parity information in the neighboring packets. In some cases, on highly reliable networks, an administrator may want to disable FEC and reduce the overhead of the multicast stream.

Software update information

A supported feature that modifies the product's default behavior is now available from Microsoft, but it is only intended to modify the behavior that this article describes. Apply it only to systems that specifically require it. This feature may receive additional testing. Therefore, if the system is not severely affected by the lack of this feature, we recommend that you wait for the next Windows Media Services 9 Series service pack that contains this feature.

To obtain this feature immediately, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Download information

Microsoft Windows Server 2003 for x86-based computers (all languages)

The following file is available for download from the Microsoft Download Center:

Download the WindowsServer2003-KB920140-x86-ENU.exe package now.

Microsoft Windows Server 2003 for x64-based computers (all languages)

The following file is available for download from the Microsoft Download Center:

Download the WindowsServer2003.WindowsXP-KB920140-x64-ENU.exe package now.

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to obtain Microsoft support files from online services

Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

File information

The English version of this software update has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

File name	File version	File Size	Date	Time	Platform
Wmsserver.dll	9.1.1.3839	3,164,160	31-May-2006	07:09	x86
Wmsserver.dll	9.1.1.3839	5,815,808	31-May-2006	04:26	x64

Steps to disable FEC on all multicast publishing points

Stop Windows Media Services. To do this, run the following command at a command prompt:

net stop wmserver
Change to the following folder where the namespace file is located:

%SystemRoot%\System32\Windows Media\Server
In Notepad, open the ServerNamespace.xml file.
Locate the Other node in the namespace.

Under the Other node, add the following node.

 <node name="Multicast" opcode="create" >

Under the Multicast node, add the following node.

 <node name="SendMulticastECC" opcode="create" type="boolean" value="false" />

Add the following node to close out the Multicast node.
```
 </node>  
```
Save and then close the ServerNamespace.xml file.
Start Windows Media Services. To do this, run the following command at a command prompt:

net start wmserver

The following is another representation of the changes to the ServerNamespace.xml file.

 <node name="Other" opcode="create" >
     <node name="Client Upgrade" opcode="create" >
          ...
     </node> <!-- Client Upgrade -->

     <node name="Multicast" opcode="create" >
          <node name="SendMulticastECC" opcode="create" type="boolean" value="false" />
     </node> <!-- Multicast -->
 </node> <!-- Other -->

Steps to disable FEC on a specific publishing point

Stop Windows Media Services. To do this, run the following command at a command prompt:

net stop wmserver
Change to the following folder where the namespace file is located:

%SystemRoot%\System32\Windows Media\Server
In Notepad, open the ServerNamespace.xml file.
Locate the Publishing Points node in the namespace
Under the Publishing Points node, find the node of the publishing point on which you want to set the property.

Under the node of the publishing point, add the following node.

 <node name="SendMulticastECC" opcode="create" type="boolean" value="false" />

Save and then close the ServerNamespace.xml file.
Start Windows Media Services. To do this, run the following command at a command prompt:

net start wmserver

The following is another representation of the changes to the ServerNamespace.xml file.

 <node name="Publishing Points" opcode="create" >
     <node name="MyMulticast_NoFEC" opcode="create" >
          <node name="Limits" opcode="create">
               ...
          </node> <!-- Limits -->

          <node name="SendMulticastECC" opcode="create" type="boolean" value="false" />
          <node name="Allow Connections" opcode="create" type="boolean" value="true" />
          ...
     </node> <!-- MyMulticast_NoFEC -->
     ...
 </node> <!-- Publishing Points -->

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional query words: WMS FEC multicast

Keywords: kbqfe kbwinserv2003sp2fix kbfix KB920140

Microsoft KB Archive/920140

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