WPA-TKIP WPA2-AES Connection speed

Question

Hi,
My customer uses controller based wireless network. There is a connection speed problem between two SSID's. First SSID uses WPA(TKIP+AES) and WPA2(TKIP+AES) encryption method and dot1x authentication method. Second SSID uses open authentication (this is a guest SSID)
802.11 a/n/ac is enable on WLC and client can connect with these methods. But clients connect to the first SSID with 802.11 b/g (54 Mbps) and connect to the second SSID with 802.11 a/n/ac. Customer wants to know why our clients connect with low speed to first SSID even if a/n/ac is enable.
Sometimes WPA-TKIP encryption methods can reduce the connection speed. Do you have any idea about that and official document about this problem?
Thanks,
Burhan,

Answer 1

TKIP and AES are two different types of encryption that can be used by a Wi-Fi network. TKIP stands for “Temporal Key Integrity Protocol.” It was a stopgap encryption protocol introduced with WPA to replace the very-insecure WEP encryption at the time. TKIP is actually quite similar to WEP encryption. TKIP is no longer considered secure, and is now deprecated. In other words, you shouldn’t be using it.
AES stands for “Advanced Encryption Standard.” This was a more secure encryption protocol introduced with WPA2, which replaced the interim WPA standard. AES isn’t some creaky standard developed specifically for Wi-Fi networks; it’s a serious worldwide encryption standard that’s even been adopted by the US government. For example, when you encrypt a hard drive with TrueCrypt, it can use AES encryption for that. AES is generally considered quite secure, and the main weaknesses would be brute-force attacks (prevented by using a strong passphrase) and security weaknesses in other aspects of WPA2.
The “PSK” in both names stands for “pre-shared key” — the pre-shared key is generally your encryption passphrase. This distinguishes it from WPA-Enterprise, which uses a RADIUS server to hand out unique keys on larger corporate or government Wi-Fi networks.
In summary, TKIP is an older encryption standard used by the old WPA standard. AES is a newer Wi-Fi encryption solution used by the new-and-secure WPA2 standard. In theory, that’s the end of it. But, depending on your router, just choosing WPA2 may not be good enough.
While WPA2 is supposed to use AES for optimal security, it also has the option to use TKIP for backward compatibility with legacy devices. In such a state, devices that support WPA2 will connect with WPA2 and devices that support WPA will connect with WPA. So “WPA2″ doesn’t always mean WPA2-AES. However, on devices without a visible “TKIP” or “AES” option, WPA2 is generally synonymous with WPA2-AES.
WPA and TKIP compatability options can also slow your Wi-Fi network down. Many modern Wi-Fi routers that support 802.11n and newer, faster standards will slow down to 54mbps if you enable WPA or TKIP in their options. They do this to ensure they’re compatible with these older devices.
In comaprison, even 802.11n supports up to 300mbps — but, generally, only if you’re using WPA2 with AES. Theoretically, 802.11ac offers theoretical maximum speeds of 3.46 Gbps under optimum (read: perfect) conditions.
In other words, WPA and TKIP will slow a modern Wi-Fi network down. It’s not all about security!