1140's not broadcasting N speeds

jlight80911 · ‎10-20-2009

Just purchased a few 1140 cisco AP's with a 2106 Lan Controller. Configured everything as stated by the manual and I can not connect at N speeds. We have two buildings, in the other building on the same network we have a 2006 Lan controller that has 4 1130's configured.

So my issue at hand right now is I am not able to connect at the N speed. Could this be an issue from mixed mode? I am a little confused on where to start.

Thank you,

Robert.N.Barrett_2 · ‎10-20-2009

What is your WLAN config? You must be using WPA2/AES (or no encryption) to get the N speeds. Post a sanitized version of your controller config if you're not sure.

jlight80911 · ‎10-20-2009

Just enabled WP2 Encryption, and setup my laptop and it only put out 54 MBPS at Excellent strength. I have a Vaio u7600. So I do not think encryption is my issue here.

Robert.N.Barrett_2 · ‎10-20-2009

WPA2 with AES, right? Not TKIP, and not WPA and WPA2 at the same time.

What wireless NIC does your u7600 use? The Intel 4965? Are the drivers up to date? Is 802.11n enabled on the controller, and on the wireless NIC?

What code level are you running on the WLC?

jlight80911 · ‎10-20-2009

Correct, WPA2 with AES.

The Viao is running the Intel 4965AGN with updated drivers

The Controller is running 5.2.178.0 Code.

Robert.N.Barrett_2 · ‎10-20-2009

Can you sanitize the controller config and upload it here? Sounds like you've got everything set correctly. The only thing that might be causing a problem is that some 4965 cards had the 802.11n disabled. I think this was only on certain ThinkPads, though. You'd know, because the card would be listed in Device Manager as a 4965AG.

Also - are you using Intel PROSet, or Windows Wireless Zero Config? What OS are you running? If you are on XP SP2, did you apply the wireless update?

jlight80911 · ‎10-20-2009

I am running Windows Vista Business, running the windows Zero Config, I also have another Vaio running windows XP with the wireless update on it. I will try to get a config file and upload within the hour.

Robert.N.Barrett_2 · ‎10-20-2009

I don't suppose you have a wireless sniffer hanging around that can show you what speeds are being advertised in the beacons, do you?

jlight80911 · ‎10-20-2009

Unfortantly i do not, i tried netstubmler just now but it did not work. One thing i noticed under the WLC on the web GUI was that the Radio policy, it only gives you the option to do a/g, b/g, or all. Mines set to b/g, to my surprise shouldn't b/g/n be in the spot? It's under the WLAN options

Robert.N.Barrett_2 · ‎10-20-2009

Cisco doesn't support n-only configurations, so the radio policy is somewhat accurate. As you noticed, you can enable/disable 802.11n support on the 2.4GHz and 5GHz radios individually via the Wireless page.

I would like to see an "n-only" option as well, but Cisco doesn't see the logic that it would be great to have 802.11b/g on the 2.4GHz radio for legacy support, and use pure (aka Greenfield) mode for the 5GHz radio. In the US, this would make a lot of sense because many people have not deployed 802.11a. Other vendors, (cough..Motorola..cough..Aruba..cough), support Greenfield mode. Of course, these folks also support 3 x 3 MIMO, which Cisco does not plan on supporting any time soon, either.

jlight80911 · ‎10-20-2009

hmm ya iv pretty much just ripped apart my network now. 2006 is out of the picture, just the 2106 is connected, and being configured by WCS 5.2.148. I have two laptops thats are N capable, the vaio, and the Dell M6400 laptop. I will try to get the config file here soon and load it up. Can you explain why i have to use WAP2 with AES security? We just use simple mac filtering and do not broadcast our network. Thank you.

jakew · ‎10-20-2009

11n HT rates require either open or AES encryption. WEP & TKIP aren't supported with 11n HT rates.

Check to be sure WMM is either allowed or required on your WLAN. WMM is also required for 11n as packet aggregation is determined by the AC.

Also... you've probably done this already, but I've made this mistake before... Be sure you've enabled 11n data rates.

jlight80911 · ‎10-20-2009

So i run just mac filtering that is all. I should be fine correct? I am getting the config file now.

Robert.N.Barrett_2 · ‎10-20-2009

The 802.11n standard requires WPA2/AES or no encryption. In Chapter 4 of the 5.2 guide, you'll see the following (forgot to ask if you have WMM enabled):

Note The 802.11n high-throughput rates are available only on 1140 and 1250 series access points for WLANs

using WMM with no Layer 2 encryption or with WPA2/AES encryption enabled.

jakew · ‎10-20-2009

Note: Greenfield mode is not the same as 11n only. GF mode doesn't have any protection bits against legacy modulation schemes. GF mode also requires chipset support, which those "other" vendors don't actually have.

We say you need at least legacy data rate enabled for good reason: to protect your network against interference from legacy wi-fi. If you have only 11n clients and no interference, then you'll only use 11n anyway, so there is no actual gain with what the "other" guys do.

Secondly, be careful what you believe about the "other" guy's 3x3 mode. Their "3x3" only means the AP can transmit out of 3 antennae, which has negligible benefits. It does not give them a 3rd spatial stream. And we'll crush them on rate/range/coverage consistency/AP quality any day.