Thank you Very much Steve ! I'll look at it right away.

Well, now I have looked at it. It's preety complicated there.
I've read a book, i have describe the composition of the data sent trough the net (the header,crc,address, data, tail,etc). What does the program do ? Does it route the message, checking crc, or something else ?
(well, to be honest I'm just starting learning C).

Thank You again