Roaming issue with android device (ZD1100 + 2x7982)

[siarhei_khirevi]

Hi. I have a ZoneDirector 1100 (9.8.3.0 build 14) managing two 7982s. The problem is that one of android (v 5.1) devices reconnects to wi-fi network after roaming from one AP to another and therefore resets its wi-fi connection. In ZD logs it looks like this:

2016/04/08  12:57:10 Low User[84:2e:27...] rejoins WLAN[...] from AP[2c:5d:93:...]
2016/04/08  12:57:10 Low AP[2c:5d:93:...] radio [11a/n] detects User[84:2e:27:...] in WLAN[...] roams from AP[2c:e6:cc:02:bb:50]
2016/04/08  12:57:10 Low AP[2c:e6:cc:...] radio [11a/n] detects User[84:2e:27:...] in WLAN[...] roams out to AP[2c:5d:93:...]

The thing is that on my corporate network (cisco) the same android device roams without any issues.

Speaking about original ZD1100+7982s setup, I have another android device (v 4.1.2) as well as apple devices (ios 9.3.1 + 6.x.x) all of which perform roaming smoothly, i.e. in logs only "roams out" and "roams from" events do appear.

The question is what can I do with ZD setup? The only relevant information I found is this post (https://support.ruckuswireless.com/answers/000002277), and I tried to activate smart-roam feature (with factor of 3) as suggested there, but this did not solve the problem.
 

[monnat_systems]

Hi

Roaming behavior is controlled by Driver in the WiFi device itself. Like in Laptops with Intel WNIC, there is a setting for Roaming aggressive which controls this behavior. in Major devices, such settings are absent. Not sure if your devices allows it or not...

On the Infrastructure side, there is SMART Roam from Ruckus

End user Device Roams frequently when signal strength of the AP's close by fluctuate very often this could be bcos of noisy RF environment. There are other metrics device considers before roaming like Retries, Packet error rate to name a few..

In general, for Roaming to be seamless, there has to be 20 % signal overlap between AP's

I am assuming that overlap between is high so reduce the transmit power manually on 5ghz (based on logs above) little bit for testing to see if that helps. ensure that there is NO major loss of coverage..

Second thing you can do if that on the smart phone, see if you can disable 5ghz and let it run just on 2,4 ghz and monitor if that takes out frequent roaming issue..

third -- try this Android App and I have NOT tried this but thought it could be a worthwhile try..

http://www.heleron.com/android-apps.html

[siarhei_khirevi]

Thank you for reply. Let me clarify my setup a bit more. I have two SSIDs, one per band (i.e. 2.4GHz radios of two APs provide one SSID and 5.0GHz radios - another one). Roaming issue described above occurred on 5.0GHz SSID. I tried i) to reduce transmit power for 5.0GHz radios, and ii) move the problematic device to 2.4GHz band and also play with transmit power there. The result is exactly the same, device simply rejoins after roaming. Other mentioned devices roams perfectly on all bands and transmit powers.

The app you mentioned simply does auto-connect to some known SSIDs resetting wi-fi connection, as users of this app complain:
https://groups.google.com/forum/?hl=en&fromgroups=#!topic/wifistrongest/X5SzdJAnF0I
https://groups.google.com/forum/?hl=en&fromgroups=#!topic/wifistrongest/VWIugYo7xZw
This app may be of use if one has two+ individual consumer-level wi-fi routers but it has nothing to do with roaming in sense of enterprise wi-fi.  

I tried to investigate the problem from device side and collected some logs after enabling "verbose wi-fi logging" in android "developer options" and using aLogcat (root) app. Here is the log during two roams; the log is quite large (about 100kB) despite I tried to remove irrelevant events.
http://pastebin.com/wdy5YNtv