This is how a normal server has to work.
> Client connect and sends a OPTIONS message
> Server send a OK message
> Client sends a DESCRIBE message
> Server send a OK message with SDP information
> Client sends a Setup message
> Server Start a stream
> Cleint sends PLAY message
> Server plays

This work good if the client is Quick time player.

but for others --->

Real player sends -> VERSION not supported After my "OK message with
SDP information".( I did every thing I can but no use.)

Windows media player doesn't respond after my "OK message with SDP
information"

VLC player --> main error: open of `rtsp://127.0.0.1:544/kpfffffff.mp3' failed: could not create access
live555 error: Failed to connect with rtsp://127.0.0.1:544/kpfffffff.mp3

this is my sample conversation with real player ...

Code:
client >
-----------
OPTIONS rtsp://127.0.0.1:544 RTSP/1.0
CSeq: 1
User-Agent: RealMedia Player HelixDNAClient/10.0.1.260 (win32)
Supported: ABD-1.0
ClientChallenge: f6dc79b0022c595b266e67ce23797b81
ClientID: WinNT_6.0_6.0.14.806_RealPlayer_R41R01_en-US_UNK
CompanyID: nkruPQ9T2tYXF9x5/5CHwQ==
GUID: 00000000-0000-0000-0000-000000000000
PlayerStarttime: [21/08/2008:12:44:49 -05:00]
Pragma: initiate-session
RegionData: 0

server >
-------------------
RTSP/1.0 200 OK
CSeq: 1
Server: RTSPserver
Date: Thu, 21 Aug 2008 16:44:49 GMT
Public: OPTIONS, DESCRIBE, ANNOUNCE, PLAY, PAUSE, SETUP,
GET_PARAMETER, SET_PARAMETER, TEARDOWN

client >
---------------------
DESCRIBE rtsp://127.0.0.1:544/kpfffffff.mp3 RTSP/1.0
CSeq: 2
Accept: application/sdp
User-Agent: RealMedia Player HelixDNAClient/10.0.1.260 (win32)
Bandwidth: 115200
ClientID: WinNT_6.0_6.0.14.806_RealPlayer_R41R01_en-US_UNK
Cookie:
cbid=gfhghhjihjmkfldmeokoruoqprjrktlufkejkielejdkfiplonroougqmrpsoqmpfkcjfhci
GUID: 00000000-0000-0000-0000-000000000000
Language: en-US, en, *
PlayerCookie: cbid
RegionData: 0
Require: com.real.retain-entity-for-setup
SupportsMaximumASMBandwidth: 1

server >
-----------------------
RTSP/1.0 200 OK
CSeq: 2
Server: RTSPserver
Date: Thu, 21 Aug 2008 16:44:49 GMT
Expires: Thu, 21 Aug 2008 16:44:49 GMT
Content-type: application/sdp
Content-Base: rtsp://127.0.0.1:544/kpfffffff.mp3
Cache-Control: no-cache
x-Accept-Retransmit: our-retransmit
x-Accept-Dynamic-Rate: 1
Content-length: 734

v=0
o=- 19557909148 1 IN IP4 127.0.0.1
s=Live Stream
i=Live Stream
c=IN IP4 0.0.0.0
t=0 0
a=tool:MComms Design
a=type:broadcast
a=control:*
a=range:npt=now-
a=x-qt-text-nam:Live Stream
a=x-qt-text-inf:Live Stream
m=video 7104 RTP/AVP 96
b=AS:100
a=rtpmap:96 MP4V-ES/90000
a=fmtp:96 profile-level-
id=245;config=000001B0F5000001B5A913000001000000012000C48D8BA98514043C1463000001B24C61766335312E34302E34
a=framesize:96 640-480
a=cliprect:0,0,480,640
a=control:trackID=1
m=audio 7106 RTP/AVP 97
b=AS:8
a=rtpmap:97 mpeg4-generic/16000/1
a=fmtp:97 streamtype=5;profile-level-id=1;mode=AAC-
hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=140800000000000000000000000000000000000000000000
a=control:trackID=2

client >
----------------------------
RTSP/1.0 505 RTSP Version not supported
CSeq: 2
Date: Thu, 21 Aug 2008 16:44:49 GMT
thanks for any future help
best regards