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.

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.