Thanks for the welcome.
I saw it in school some years ago, i dont know if the teacher had it downloaded from the internet or had it on a cd-rom..
I think perhaps cisco or some other manufactuerer made the film.
It showed how the datatransfer on the internet works. It showed tha data packages being loaded in to some sort of small "trucks" and then they drove/flew on the information-highway. When they reached the destination there where a firewall of some sort with giant arms bouncing off the trucks with viruses and other nasty stuf, only letting the right trucks in.
This is about all i remember. I think the film was maybe 10 minuttes or so.
Sorry for any misspelling - english is not my native languages.