 Cat6 vs Cat6a. Cat6a is the next category of data cable after Cat6. Some manufacturers make a Cat6e, Cat6 enhanced cable. However, this is not officially ratified by the standards boards, therefore Cat6a is the next category up from Cat6. The main difference between Cat6 and Cat6a is that Cat6a by comparison has a bandwidth of 500 MHz to 250 MHz. So, in essence 2 and a half times the capacity. Cat6 had twice that of Cat5e. Furthermore, at the standardized 90 meters permanent link, Cat6a has the capability to transmit 10 gigabit ethernet speeds. Although Cat6 is capable of 10 gigabit ethernet, to 55 meters it isn't a standard length for data cabling design considerations. Therefore when designing a network for 10 gigabit, Cat6a is always the starting point of choice.