Hi Marcos,
my network was set to "windows settings" (in german Windows Einstellungen). I changed it to "home/office" (Heim-oder Büronetzwerk) on both PCs.
Blocked comunications:
- Windows Media Player Sharing.
- VLC media Player
- PCxyz (the PC which should view the stream)
I've unblocked the communication of the VLC and the PCxyz. Now I can watch the stream.
Thank you very much for the fast an accurate support. Only problem is I can't watch a webcam stream, but I think it is a VLC configuration problem.