Wireless Roaming Issue

[Ralph_Allen]

Using an Extreme Networks WM3700 Controller with 4610APs. I run a ping test when roaming around floors and get dropped for 1-2 pings often. Happens on all 5 floors. Is there something in the WM3700 Controller configuration that needs to be set for seamless roaming or is this behavior common.

[markwood1122]

A loss of one or two pings during a roam can happen while the client is switching between APs, especially with older clients or if the AP coverage overlap isn’t ideal. I’d check the signal level where the client starts roaming and make sure adjacent APs have enough coverage overlap. It would also be worth testing with a couple of different client devices, since the client itself usually plays a big role in deciding when to roam. If the drops consistently happen in the same areas, I’d check the RF/channel plan and AP power levels before changing anything on the controller.

[Ronald_Dvorak]

Sorry but it's hard to give good feedback with the limited information in your post.

The most important thing for WLAN troubleshooting is to know the behavior of your test equipment.
If your WLAN adapter is "not very good" a ping loss could be normal for that adapter (unfortunately there are still a lot of very bad adapters on the market).
Another type of WLAN adapter could roam without a ping loss in the same situation.

My laptop for example... I know exactly how my adapter is configured (802.11n 5GHz only, aggressive roaming), sometimes one ping loss during roaming, +3dB better signal then most other WLAN adapter.

So play around with your client on a open/none SSID to understand what "normal" is for your device and test again other adapter/devices to see a difference.

[Jon_Linton]

It can take a significant amount of time to roam when performing the whole .1X hand shaking. With a PSK roam times should be sub 40ms. Test with a PSK and see if the problem persists. The reason I say this is to take variables(.1X auth) out of the equation. If roam times improve with a PSK then you may need PMK caching or fast roaming enabled. If it does not improve the client and WLAN design may a better starting point.

[Sumit_Tokle]

Have you enabled the fast roaming on WM controller?
The bridging mode should be tunnel for the wireless lan.

If above setting are correct then try configure the wireless clients NIC card setting,

The following is copied from Intel wireless client online help page: Roaming Aggressiveness
This setting allows you to define how aggressively your Wi-Fi client roams to improve connection to an access point. Click Use default value to balance between not roaming and performance.

· Lowest: Your wireless client will not roam. Only significant link quality degradation causes it to roam to another access point.

· Medium-Low/Medium-High: Allow Roaming.

· Medium: Balanced setting between not roaming and performance.

· Highest: Your Wi-Fi client continuously tracks the link quality. If any degradation occurs, it tries to find and roam to a better access point.