hello,
very often on some vod file i get this error :

19:06:39 815607869 5.84.237.244 - 4775 8825462 467.798 pi6.mp4 1 1455320 8818948 0 204139541 3007.56 pi6.mp4 Insufficient Bandwidth [6,4]

the file is encoded 480x320, H264/AAC, Baseline3.0, video 500kbp/s, audio 48kbp/s .
the server is connected with symmetric 10Gbp/s line and and the network usage is @ 5% .
Wowza 3.5 on 8core processor dual xeon, 24GB RAM .
Flowplayer 3.2 .

what is mean ?
thanks,

steve