Why RTSP/1.0 PLAY command is not working, it always get 456 error?
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I don't know why a media server returns 456 error via RTSP in the following sequence. I am in a deep terrible, I wasted many time for this problem. Please help me!!

    [C->S]
    SETUP rtsp://powerhost.live.powerstream.net/00200187_live2/audio RTSP/1.0
    Cseq: 1
    Transport: RTP/AVP;unicast;client_port=4588-4589;mode=play
    
    SSEntry: 4294967295 1 1 rtsp://powerhost.live.powerstream.net/00200187_live2/audio
    
    [S-> C]
    RTSP/1.0 200 OK
    Blocksize :  1452
    Transport : RTP/AVP/UDP;unicast;server_port=5004;client_port=45884589;ssrc=7a257f0b;mode=PLAY
    Date :  Thu, 26 Jul 2012 04:19:30 GMT
    CSeq :  1
    process_read_stream: Session :  18198336478711778096
    process_read_stream: Server :  WMServer/9.1.1.5001
    process_read_stream: Supported :  com.microsoft.wm.srvppair, com.microsoft.wm.sswitch, com.microsoft.wm.eosmsg, com.microsoft.wm.fastcache, com.microsoft.wm.packetpairssrc, com.microsoft.wm.startupprofile
    Last-Modified :  Sat, 30 Dec 1899 00:00:00 GMT
    Cache-Control :  x-wms-stream-type="broadcast", no-cache, no-user-cache, private
    
    [C->S]
    PLAY rtsp://powerhost.live.powerstream.net/00200187_live2/audio RTSP/1.0
    Cseq: 2
    Session:  18198336478711778096
    
    [S-> C]
    RTSP/1.0 456 Header Field Not Valid
    Date :  Thu, 26 Jul 2012 04:19:31 GMT
    Session :  18198336478711778096
    Server :  WMServer/9.1.1.5001