what is the need for test.sdp wile streaming using RTSP

[talelelalit]

I am using vlc 0.8.6 to stream media files using RTSP.
I am able to run the commands using RTSP and are working too.
I am using following command:

vlc <input stream> --sout '#rtp{sdp=rtsp://<ip address>:<port>/test.sdp}'

My question is :
Why we need test.sdp in above command?

Can any one help me?


Thanks in Advance,
--Lalit

[Rémi Denis-Courmont]

test.sdp is an example. But you should refrain from running the stream at the "root" of the RTSP server because this causes some interoperability problems.