Extremely slow connection speed AIR-WLC-5508 ALL Clients connected

[Hey is that Leo]

Hello!

We recently switched from a WLC 2504 to a WLC 5508 controller, which is proving to be a huge mistake. First off, the massive nature of the 5508 v. the 2504 ... absolutely ridiculous!

The 5508 has been configured almost identically to the 2504, with some minor tweaks courtesy of the 'Best Practices' wizard. It may be attributed to the software version, although I haven't found anything that stands out when doing a web search on this matter.

- WLC 5508 using IOS 8.5.151.0

I'm seeing something that I've never seen before .. the wireless rates are all either A or G. The AC and the like are gone .. not sure if this is how the 5508 functions? Normally, there are two-letter bands showing... could this be the culprit?

See photo:

There were some changes to QoS, due to the Best Practices suggestions... Specifically, QoS to Platinum and Fast Lane enabled. I've since disabled WMM, QoS is back to Silver (best effort) .. Fast Lane is still enabled.

We have a WPA2 PSK WLAN and an 802.1x Active Directory WLAN. Both WLANS are impacted. Speeds went from ~300mbps to ~20mbps ..

Looking in to changing out the IOS image unless anyone has any thoughts?

Greatly appreciated ...

Thanks,

Leo

[Scott Fella]

I don’t think it’s the device... the changes to best practice is not for everyone and I have never had 100% of the recommendations ever enabled. You need wmm for 802.11ac so that is why you are seeing a and g. Fastlane is t something I enable without testing

[Leo Laohoo]

Same here.  I've never used the "Best Practices" feature.  
Fast Lane?  Turn it off.  

802.11ac?  Turn it off.

[Rasika Nayanajith]

Specifically, QoS to Platinum and Fast Lane enabled. I've since disabled WMM, QoS is back to Silver (best effort) .. Fast Lane is still enabled.

Disabling WMM is the issue causing it. Once you disable it all your 11n/11ac has to fall back to legacy rates (max 54Mbps) as WMM is mandatory to achieve higher data rates (MCS).  Enable WMM (set it to required) and test it again.

HTH

Rasika

*** Pls rate all useful responses ***

[Hey is that Leo]

Thank you for the prompt responses! Re-enabling WMM was certainly a great recommendation. I should have known better than to disable it, for some reason I associated WMM with QoS. 

Speed is still far lower than with the 2504; not even getting the 300mb speed. My expectation was to get as close to gigabit as possible, given LAN speeds are over 800mbps.

[Scott Fella]

Well it might still be your config. Make sure you have channel width defined higher than 20mhz on 5ghz.

[Rasika Nayanajith]

Speed is still far lower than with the 2504; not even getting the 300mb speed. My expectation was to get as close to gigabit as possible, given LAN speeds are over 800mbps.

What AP models you got & what clients are you testing with? How many clients in a given AP when you do this testing?
Pls "show advanced 802.11a summary" & "show client detail <mac_addr>" output to get an idea.

Pls note WiFi is a half duplex medium, so you will never come close to wire speed. Also lot of overhead for management and control frames, so airtime for Data frame is typically in the range of 40-60%. Therefore when you do a throughput test,  you will not come close to those MCS data rate values given below

http://mcsindex.com/ 

HTH

Rasika

*** Pls rate all useful responses ***

[Hey is that Leo]

Hi --

It's a residential setting with ~ 25 clients with ALL devices (PCs, Smartphones, Tablets, TVs, etc.).

We have (4) 3702I APs and (1) 1552E..also in the process of getting a 1562I up and running as well.

I would never expect to see LAN speeds with WiFi...I do expect to see speeds over 300mbps now that I am using a 5508, after getting 300mbps with a 2504 WLC

Please see below photos:

[Hey is that Leo]

I should add they are connected to a 2960s switch. I may have moved the port connections around during the WLC swap. How should the ports be configured for the WLC and APs? I may have them as switchport mode acsess for everything.

[Scott Fella]

Ports should be access ports but also can be a trunk port, doesn’t matter. Your speed depends on the clients devices and also if you are connecting on 5ghz vs 2.4ghz.

[Hey is that Leo]

Hello!

Ended up going back to the WLC 2504. Speeds are back near 300Mbps, much lower than the Cisco APs and broadband connection can do; however, faster than what we were getting with the AIR 5508 WLC. The 5508 is 10x bigger and consumes more wattage .. no wonder it's $50 on eBay right now and the 2504 is still averaging $250.

Thanks for the responses, everyone. Much appreciated!

[Scott Fella]

The only difference people choose the 5508 is if they need more AP’s than what the 2504 can provide. Both have gig interfaces and the only difference is the backplane which I really don’t think many will hit. If you ran the same code and had the same config, there should be no difference in throughput or user experience. I have a few 5508’s at home for testing but I rather run the 2504 because of the footprint. This is the same for other models I run at home.