Differences of Cat 5e, Cat 6 & Cat 6a

     What's important to note here, is that even Cat5e supports Gigabit Ethernet. So, unless you think you might need 10 Gigabits across a given link, Cat5e will do the trick just fine. Cat5e can even handle 10 Gigabit Ethernet at short distances, so within a server room for example as a backbone link, Cat 5e cable is rated to handle it. What's more likely though, is that you'll be running any 10 Gigabit connections over fiber.
       It may sound like a single lowercase letter is all that sets Cat6 apart from Cat6a, but that one little letter stands for augmented, and represents a world of difference. Even while Cat6 is still gaining popularity as the go-to cable standard for network installers, Cat6a has come along in and outdone it in performance, crosstalk prevention, and even size. Trying to decide which one is right for you or your clients?

Category 5e Cable:

       Category 5e cable is now the minimum recognized cable for data networking applications, as defined by the current standard. Like Category 5 cable, it also is rated for up to 100 MHz frequencies. Additional performance standards enable it to support transmission speeds of up to 1000 mbps ("gigabit Ethernet").

Category 6 Cable:

       Category 6 cable, the standard for which was defined in 2002, raises the bandwidth limit to 250 MHz; as a practical matter, Category 6 cable, like Category 5e, currently supports gigabit Ethernet (speeds of up to 1000 mbps). When the standard was released, Category 6 cable was described as "being able to support future applications." In practice there are few areas in traditional networking environments where Category 6 cable would be required (as opposed to Category 5e cable). Shorter runs of Category 6 cable can even support speeds of up to 10 gigabits per second (10,000 mbps), a speed that would otherwise require Category 6a wire. Category 6 cable is also often necessary for some non-traditional uses; for example, converters that can transform HDMI video signals for transmission over network wire often require the additional frequency support found in Category 6 cable.

Category 6a cable:

       This is the newest category standard recognized by the TIA (2008). Category 6a cable can support frequencies up to 500 MHz and speeds up to 10 gbps. Demand is still relatively low for Category 6a wire, as of this writing. This is, in part, due to fiber-optic cable already supporting 10 gigabit speed (often written as 10gE, for 10 gigabit Ethernet), rather than by twisted-pair copper cable.