Extremely slow WiFi > 100Kbps 802.11n

[frodestra]

Hi, I have been troubleshooting a slow WiFi network for awhile and its still going extremely slow (below 100Kbps):

- The APs are of the type AP2702 and the issue only affect on single office while the other 5 offices run at normal speed ( 100 Mbps - The speeds are collected using Wireshark) 

- All AP are managed by a WLC 5520 cluster and all are in local mode.

- There are no interferers and the Air Quality is 100 in the affected office.

- The switchports are in full duplex 1Gbps for which the APs in the affected office are connected to

I have

- Disabled 2,4Ghz on the all APs

- Disabled 6 and 9 Data rates on 5

- Channel width 40 MHz

I'm running out off options here.. Is there anything more I should check or change?

[ali aqrabawi]

if you change the AP mode to flexconnect and the WLAN to local switch does the performance improved ? (in case there is WAN between the AP and the WLC).

do you use different WLAN for that specific site ? or it same wlan ? 

if its differenet then can you share "show wlan <wlan id>" , 

collect show logging from the AP and check if there is anything interesting . 

collect show client detail <client MAC> and check the RSSI/Noise .