Just Djarek's cast system works on windows after opening ports, but on OVH [ Linux ] it don't work.Shouldn't be anything blocking the ports on Linux by default, but if you use a router you need to forward that port.
Find your router model here and follow their guide:
http://portforward.com/
You can check if the port is open here (you need to have something running on that port):
http://canyouseeme.org/
It works on windows ( why won't in linux )Since you use OVH the ports shouldn't be blocked.
Something with the sources that do not work on Linux?