Question : Problem: RJ-45 cable max length

Whats the maximum length can have a RJ-45 cable to be connected from my router to a device? How many meters?

Answer : Problem: RJ-45 cable max length

The maximum length varies with the speed you are trying to attain (10/100/1000) and the quality of the cable (Cat5, Cat5e, Cat6)

Check out http://www.bluemax.net/techtips/networking/Wiring_Tips/Wiring100TX/letsmakesomecables.htm