Cisco console, USB and RJ45?
Solution 1:
Many network devices use the Yost RJ45 pinout for RS-232 console communications. Cisco is probably the best known, but certainly not the only. The switch should have come with a DB9 to RJ45 blue cable. You can just pickup any USB-DB9 Serial adapter (though I highly recommend getting one with a Prolific PL2303HX Rev D Chipset, as they "just work" and are compatible with a wide array of OSes).