[Red5] Problems with buffering MP3 when playing from file ( not stream)

[Mamontov Sergey V.]

I found some mysterious behavior Red5 with stream, when i calling
NetStream("some_file.mp3") before calling play I setup
NetStream.bufferTime = 15;
But when i calling play, no buffering is shown as expected< at server
log I see:

INFO   | jvm 1    | 2007/11/14 22:21:37 | Unhandled ping: Ping: 3, 0, 15000, -1
INFO   | jvm 1    | 2007/11/14 22:21:37 | 00 03 00 00 00 00 00 00 3A 98

Is anybody know what it can be?

And also I don't know how to invoke pause (of streamService ) when I
need. Can someone help me with this?