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Cisco has released WLC code (on 18th Dec 2013) to support new 3700 series AP which supports 802.11ac. Cisco 3700 AP supports 1.3Gbps data rate (wave1 of 802.11ac) with 4×4 MIMO & 3SS (Spatial Streams). Even though AP supports 1.3 Gbps limiting factor would be the 1G Ethernet port (at switch end & AP end).

To get the first hand experience, we have decided to upgrade one of our 5508 WLC to release & get couple of existing 3600 AP swapped with 3700. Like any other software releases, this code comes with loads of un-resolved bugs. So carefully review the full release notes prior to upgrade your controller into this.

Below shows simple testing scenario we used to measure the performance of 802.11ac capable clients. We had 3 different products which supports 802.11ac, Google Nexus 5 (1SS), Samsung Galaxy S4 (1SS) & Macbook Air (2SS). I have used iPhone5 (802.11n only)

802.11ac-00802.11ac only support in 5GHz & You have to set 80MHz channel width as 802.11ac use 4 channels bonding together to give higher throughput. So here is my WLC 802.11a/n/ac band DCA settings.

802.11ac-02I have let RRM to determine the Channel allocation & power levels based on the environment. Here what my 3702 AP settles into.

802.11ac-03Here is what I see few minutes later on the client association on this AP. As you can see there are 3 clients connected in 802.11ac mode & others with 802.11n in 5GHz band. (Note that I have disable 2.4GHz band on this AP)

802.11ac-04Then to measure the throughput, we have measure the upload & download speed with iperf application. I have measured data in each 1s interval for 5min duration.

Here is the result with MacBook Air. Once you connected to the SSID, you will see the data rate as 867Mbps (This is max data rate this client supported & not the actual throughput)

802.11ac-05Here is the actual download throughput of MBA over 5 min period. We got around 236Mbps in average.
802.11ac-06Here is the actual upload throughput of MBA over 5 min period. Average upload throughput is 290Mbps.
802.11ac-07If you connect 1SS devices like Nexus5 or Samsung S4, you will see data rate as 433Mbps. Again this is not the real throughput & here are the throughput result we got for Nexus 5.

802.11ac-08802.11ac-09Here is what we got for Samsung S4.

802.11ac-10802.11ac-11To comparison I have take iPhone5 download throughput. We got around 88Mbps in average.802.11ac-12As you can see the overall performance is very good & clients are getting very high throughput. But still I feel 802.11ac performance is fluctuating drastically compare to 802.11n result.

We have to wait & see when more & more devices comes with 802.11ac to bench mark the 802.11ac performance.

Update@14th Jan
As I think 802.11ac performance with cisco 3700 is little bit slow, just tested the Macbook Air with AirPort Extreme AP to get a baseline of that client performance. Here is the test result when MBA connect to AirPort Extreme. As you can see it is pretty consistent 561Mbps with regular interval dropping to 150Mbps resulting 526Mbps average throughput.

802.11ac-13Update@22th Jan
Noticed couple of bugs in CCO related to this degraded performance in 7.6 with 3700/3600, specifically with Apple devices

ap3700 uses 8 replay counters w/ clients that support only 1 (ARP fails)

Macbook Air, Macbook with 802.11ac chipset see  dropped packets and odd ARP behaviors when associated to the 5.0GHz  radio of a Cisco 3700 Series access point with WPA2 security.

To reproduce, all of the following conditions must be met:
– Software:  WLC code
– AP/Radio: Cisco 3700 Series AP only on 5.0GHz radio
– Clients:  Macbook Air w/ 802.11ac, Macbook Pro w/ 802.11ac, and Intel 6300 v15.9.2.1
– Switches:  Only reproducible with certain switches, such as Catalyst 6500 and Catalyst 3560-CG

Workaround: Upgrade  or downgrade the client driver software to a version that supports  reception with multiple replay counters (which is standard).

Known Fixed Releases: 7.6(100.4), 7.6(101.6)

7.6: Broadcom client connectivity problems if WMM enabled w/ ap3600

Symptom: Wireless clients utilizing Broadcom chipsets may have trouble associating or may experience traffic hangs when associating to a Cisco Aironet 3600 Series AP running the release.

This bug will only occur with the Cisco Aironet 3600 Series APs on Wireless LAN Controllers with Software and WMM Enabled

Workaround: Disable WMM

Fixed Releases: ,

ap3700 SC3 + Intel 6300 v15.9.2.1 traffic hangs with 802.1x/wpa2

An Intel 6300 AGN wireless client associated to a 3700 ap may periodically fail to pass traffic, while remaining in the WLC Run state, and appearing connected from the client perspective.

Conditions: WLC & wlan 802.1x wpa2/aes
Intel AGN 6300, latest driver., 11/24/2013

configure authentication and encryption type other than 802.1x wpa2/aes

Above bugs listed as part of this CSC forum thread.

Update @23-02-2014
Cisco has given customers to go for pre-release of 7.6MR1 ( which has the fix for above bugs. So if you are running today , better off go for this maintenance release code. Here is the link to get that code

7.6MR1 Availability

Update @01-05-2014
Cisco will release 7.6MR2 to address few other known bugs & to support newer 11ac AP model (2700 series). To get Pre-7.6MR2  you can follow this link