Thanks for the quick answer!
My cable is 15m long. I guess that I'm below the "risk for interference level".
I don't really understand what you mean here -- a combination between not-being-native-English-speaker and not-being-technical-enough. But I can try to say what I think I understand ;-)
By "Just stick a normal end on it", I understand that I plug in the cable as it is, with the RJ45 contact the cable was provided with when I bought it, into the box on the one end, and into the router on the other end.
As for " make sure it's well-protected from the elements", I am clueless.
I qualify for this part. Cable is on the first floor (and the 0th as well...).
First visit to the forum by the way. Thanks for the great welcoming committee you are provided me with!
/fred99