thanks for that,
in fact, some of my clients need the same infos and this is why I first try to do multicasting
but reaching multiple clients on the same host is different than addressing one packet to different hosts...
for now all my clients try to connect around each 10 second to server to query some infos and to update their state
but I could guarantee that only one client will try to connect at a time
so it could be difficult to use a server which doesn't accept more than one connection...
or maybe i'm wrong and there is another solution, not based on networking ?