Understanding Fast Recovery

Fast Recovery is accomplished by enabling forward error correction (FEC) on a publishing point. With the help of FEC, Windows Media Player can usually recover lost or damaged data packets without having to request that the data be resent by the Windows Media server. In environments that are subject to latency problems, such as satellite networks and other wireless networks, this process of receiving data is much more efficient. You can specify the amount of error correction data transmitted per span of data sent on the Forward Error Correction properties sheet.

Notes

• Forward error correction can only be used with players that connect to your server through the RTSPU protocol.
• The Fast Recovery feature is only used by clients that connect to a unicast stream.
• Users may develop customized players that request FEC data packets. If you have not specified a number for the FEC packets per span setting, the server will attempt to deliver the amount of FEC data requested by the player. Excessive FEC data requests can cause the server's processor to be overloaded and may result in poor server performance. If you notice that the processor use is out of the normal range, set the FEC packets per span setting to a lower number.
• Forward error correction is available only if Windows Media Services 9 Series is running on the following editions of the operating system: Windows Server 2003, Enterprise Edition and Windows Server 2003, Datacenter Edition. If you are running Windows Server 2003, Standard Edition, this feature is not supported.

Related topics

• Forward Error Correction - general properties
• Understanding Fast Streaming
• Using the RTSP protocol