Overview From the outside, Cat 6 cables look identical to Cat 5 and Cat 5e cables. They use the same RJ45 connectors and are backward-compatible with Cat 5/5e Ethernet networks. Internally, Cat 6 cables retain the same "twisted pair" wiring scheme with eight internal wires. The primary difference between Cat 6 and Cat 5 is that Cat 6 operates at 250 MHz, while Cat 5 and 5e operate at 100 MHz. The higher frequency enables Cat 6 cables to transfer data more quickly.