1. 
Wrong initiation:
GStreamer session (+: GSrtreamer -: Camera)

+OPTIONS rtsp://192.168.150.200/live.sdp RTSP/1.0
+CSeq: 0
+Date: Fri, 22 Aug 2008 10:55:28 GMT

-RTSP/1.0 200 OK
-CSeq: 0
-Date: Fri, 22 Aug 2008 12:55:31 GMT
-Public: OPTIONS, DESCRIBE, PLAY, SETUP, TEARDOWN

+DESCRIBE rtsp://192.168.150.200/live.sdp RTSP/1.0
+CSeq: 1
+Accept: application/sdp
+Date: Fri, 22 Aug 2008 10:55:28 GMT

-RTSP/1.0 200 OK
-CSeq: 1
-Date: Fri, 22 Aug 2008 12:55:31 GMT
-Content-Base: rtsp://192.168.150.200/live.sdp/
-Content-Type: application/sdp
-Content-Length: 343
-
-v=0
-o=RTSP 1219409731 337 IN IP4 0.0.0.0
-s=RTSP server
-c=IN IP4 0.0.0.0
-t=0 0
-a=charset:Shift_JIS
-a=range:npt=0-
-a=control:*
-a=etag:1234567890
-m=video 0 RTP/AVP 96
-b=AS:0
-a=rtpmap:96 MP4V-ES/30000
-a=control:trackID=1
-a=fmtp:96 
-profile-level-id=3;config=000001B003000001B509000001000000012000C48881F4514043C1463F;decode_buf=76800
+SETUP rtsp://192.168.150.200/live.sdp/trackID=1 RTSP/1.0
+CSeq: 2
+Transport: 
+RTP/AVP/UDP;unicast;client_port=39498-39499,RTP/AVP/UDP;multicast,RTP/AVP/TCP;unicast;interleaved=0-1
+Date: Fri, 22 Aug 2008 10:55:28 GMT

-RTSP/1.0 503 Service Unavailable
-CSeq: 2

VLC session ( +:VLC, - :Camera)
-----------------------------
+OPTIONS rtsp://192.168.150.200/live.sdp RTSP/1.0
+CSeq: 1
+User-Agent: VLC media player (LIVE555 Streaming Media v2008.04.02)

-RTSP/1.0 200 OK
-CSeq: 1
-Date: Tue, 19 Aug 2008 16:42:30 GMT
-Public: OPTIONS, DESCRIBE, PLAY, SETUP, TEARDOWN

+DESCRIBE rtsp://192.168.150.200/live.sdp RTSP/1.0
+CSeq: 2
+Accept: application/sdp
+User-Agent: VLC media player (LIVE555 Streaming Media v2008.04.02)

-RTSP/1.0 200 OK
-CSeq: 2
-Date: Tue, 19 Aug 2008 16:42:30 GMT
-Content-Base: rtsp://192.168.150.200/live.sdp/
-Content-Type: application/sdp
-Content-Length: 343
-
-v=0
-o=RTSP 1219164150 610 IN IP4 0.0.0.0
-s=RTSP server
-c=IN IP4 0.0.0.0
-t=0 0
-a=charset:Shift_JIS
-a=range:npt=0-
-a=control:*
-a=etag:1234567890
-m=video 0 RTP/AVP 96
-b=AS:0
-a=rtpmap:96 MP4V-ES/30000
-a=control:trackID=1
-a=fmtp:96 
-profile-level-id=3;config=000001B003000001B509000001000000012000C48881F4514043C1463F;decode_buf=76800
+SETUP rtsp://192.168.150.200/live.sdp/trackID=1 RTSP/1.0
+CSeq: 3
+Transport: RTP/AVP;unicast;client_port=36774-36775
+User-Agent: VLC media player (LIVE555 Streaming Media v2008.04.02)

-RTSP/1.0 200 OK
-CSeq: 3
-Date: Tue, 19 Aug 2008 16:42:30 GMT
-Session: 2579728;timeout=80
-Server: PVSS
-Transport: RTP/AVP;unicast;client_port=36774-36775;server_port=5556-5557

+PLAY rtsp://192.168.150.200/live.sdp/ RTSP/1.0
+CSeq: 4
+Session: 2579728
+Range: npt=0.000-
+User-Agent: VLC media player (LIVE555 Streaming Media v2008.04.02)

-RTSP/1.0 200 OK
-CSeq: 4
-Date: Tue, 19 Aug 2008 16:42:30 GMT
-Session: 2579728;timeout=80
-Server: PVSS
-RTP-Info: url=rtsp://192.168.150.200/live.sdp/trackID=1;seq=0;rtptime=0
-Range: npt=0-
-RTCP-Interval: 250

+TEARDOWN rtsp://192.168.150.200/live.sdp/ RTSP/1.0
+CSeq: 5
+Session: 2579728
+User-Agent: VLC media player (LIVE555 Streaming Media v2008.04.02)

-RTSP/1.0 200 OK
-CSeq: 5
-Session: 2579728

The camera type is Vivotek IP7138. I think the main difference is that 
the VLC client doesn't use the interleaved parameter in the SETUP 
command

----------------------------------------------------------------------------

2. 
Missing TEARDOWN when the program is closed. Only a PAUSE is sent. On 
some cameras this prevents the start of the next session for a while.
(Pesti Vivotek 192.168.2.90)