RTSP audio stream works fine on BlackBerry 9000 but there is no sound on BlackBerry 8320

i have this code in java, and i can hear the rtsp audio stream in blackberry 9000, but while i can see in server logs that rtsp stream is being transmitted and i can notice phone getting content i hear no sound on BlackBerry 8320.

javax.microedition.media.Player ppp = javax.microedition.media.Manager.createPlayer("rtsp://rtspink;deviceside=true;apn=streamingAPN;");
ppp.addPlayerListener(RadioPlayingScreen.this);
ppp.realize();
VolumeContr开发者_Python百科ol vc = (VolumeControl) ppp.getControl("VolumeControl");
if (vc != null) {
   vc.setLevel(100);
}
ppp.prefetch();
ppp.start();

As i said this code works perfect on blackberry 9000, but i hear no sound on blackberry 8320.

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It seems like BB 9000 and BB 8320 are using different protocol port to communicate with the rtsp server and the ones BB8320 were using was filtered by operator's firewall.