What would cause an 802.11n, at 5 GHz, to cap at 54 Mbps? (wireless network interface card is 802.11n)

[stephen_tercino]

There is only one AP. Half split method isolated that the AP is propagating 54 Mbps at 5 GHz; 2.4 GHz is turned off to isolate at 5 GHz. The model of the AP is a 7372.

[monnat_systems]

Hi Stephen,

Supported data rates on ZF7372 are as follows

• 802.11n: 6.5Mbps – 130Mbps (20MHz) 6.5Mbps – 300Mbps (40MHz)
• 802.11a: 54, 48, 36, 24, 18, 12, 9 and 6Mbps
• 802.11b: 11, 5.5, 2 and 1 Mbps
• 802.11g: 54, 48, 36, 24, 18, 12, 9 and 6 Mbps

If your NIC is 802.11n however configured to operate as 802.11a card then you may see this. Please check your WNIC configuration to see if it correctly configured or not.
By the way, How you are checking or seeing that ZF 7372 dual band AP at 5 GHz is capping at 54 Mbps?
Which WNIC is in question here?

[rahul_koul]

Stephen,

Please verify the following:

1. The wireless drivers are up to date. I have seen it help previously!
2. The SSID is not configured for TKIP or WEP encryption. That causes an 802.11n AP to operate at g speeds.

Hope it helps.

Cheers,
Rahul

[kitty_ninja]

Rahul,

Thank you for the straight forward answers. You were right on point. TKIP was in causing the problem.

Thanks Again!!