Cat5e (350Mhz) will support 1Gbit, it's not optimal. The cat6(550Mhz) is however optimized for the 1G speeds, due to it's increased resistance to cross talk, and better signal to noise ratio. For general low volume data usage, 5e is good enough. Don't replace it, however if you are wiring new, go cat6 every time."Mar 1, 2012