please help, we've got some strange problem with RTP/RSTP

[Farkas Levente]

hi,
in short our rtsp server not working:-(
but neither:
- gst-rtsp-server,
- vlc's rtsp server,
- mplayer's live555.

in a bit more detail, the setup:
- we've got high resolution 2MP, 3MP, 5MP and high fps 12-25 fps ip
cameras which has buildin rtsp server and can stream the video in rtsp.
- our network is not perfect. there are a few pc which are behind 2-3-4
switch (ie. the shortest path from one server to the client goes through
2-3-4 switch).

what is always working:
- if we connect from a pc directly to the ip cameras('s rtsp server)
then we can get the proper video stream even with gstreamer, vlc etc.

what is not always working:
- if we create an rtsp server on pc (eg Wim's gst-rtsp-server) which do
nothing just re-transmit the rtp stream from the camera with this
pipeline on the server side:

rtspsrc location=rtsp://admin:12345@192.168.209.209:554/h.264/ch1/main !
rtph264depay ! rtph264pay name=pay0 pt=96

and on the client side with this:
gst-launch rtspsrc location="rtsp://192.168.209.200:8554/test" !
decodebin2 ! xvimagesink

then on some network segment we've got gray images most of the time.
we try to replace both the client and then server to vlc and mplayer
(just to know whether it's a gstreamer bug or not) and neither
combination working. but if we connect directly to the camera it's
always working with all clients.

an even strange thing if we start to stream on the server side from an
mkv file (with the high resolution high fps file) than the same thing
happened on the client side. so the problem is not the source of the
rtps server.

one small tipp: if we lower the mtu to 300 (!) then it's working, but
obviously we can't use this settings in a real environment.

so what can be the problem? any help would be useful.


-- 
  Levente                               "Si vis pacem para bellum!"