Unidentified time delay when roaming between APs

[howartp]

Hi,

 

We've got a new Ruckus setup installed, presently four APs as a kind of trial before going further.

 

Two of them are in one building (Etasc) and two in another (Craven).

 

If you roam between the two in Craven, internet browsing is almost seamless as you roam. However if you roam between the two in Etasc, internet browsing stops for about 6 minutes with the little spinning thingy (or other 'loading' indication depending on browser) then suddenly the page loads and browsing continues normally.

 

The same happens both ways between Etasc APs, and we have swapped the APs from Craven with the Etasc APs and the problem remained in Etasc - so we're suspecting it isn't Ruckus that is causing the problems.

 

Anyone any ideas what might be the cause?

 

Cheers,

 

Peter

[MacGeek]

Can you install the Advanced Intel Drivers on a notebook and roam around. There is an option to view which AP you are connected to and which are in range. Should help you determine if the Etasc AP's are passing off to each other correctly. Then compare this to the working ones.

[howartp]

Can you install the Advanced Intel Drivers on a notebook and roam around. There is an option to view which AP you are connected to and which are in range. Should help you determine if the Etasc AP's are passing off to each other correctly. Then compare this to the working ones.

Thanks for the reply.

 

We've done this by two other methods - inSSIDer shows us the APs and SSIDs correctly, and I can see in the Ruckus console which AP we are connected to; it just takes ages to then permit browsing after we've connected.

 

Peter

[DarrenG]

Do you have a ZoneDirector in the setups ?

[howartp]

Yep, sorry - that's the Ruckus console I was talking about.

 

It's a 1100 I believe.

 

Peter

[DarrenG]

Have your tried reducing your AP power? By default it should be auto but if you go to Configure -> Access Points in your zoneDirector you can adjust the TX power to MIN and see if this helps. Im thinking maybe your APs are overlapping too much?

[DarrenG]

Or failing that do you have an option in the wireless driver software of your client device to turn up roaming sensitivity?

[howartp]

Have your tried reducing your AP power? By default it should be auto but if you go to Configure -> Access Points in your zoneDirector you can adjust the TX power to MIN and see if this helps. Im thinking maybe your APs are overlapping too much?

 

Or failing that do you have an option in the wireless driver software of your client device to turn up roaming sensitivity?

 

Hi Darren,

 

Yes, I turned the APs down to Min at various points during the tests.

 

Most of the clients will be iDevices and their competitors, which don't let you at the WNIC to configure anything without jailbreaking.

 

Peter

[Bruce123]

Probably too obvious but have you checked what channels the APs are on (and tried changing them to see what happens)?

 

Also, try setting off a ping -t when moving around to see what happens to IP connectivity as you roam as it could be an application issue, rather than a network issue.

Edited April 10, 2012 by Bruce123

[howartp]

Probably too obvious but have you checked what channels the APs are on (and tried changing them to see what happens)?

 

Interesting question.

 

Both APs in Craven have always been on channel 1 (auto assigned) and worked seemlessly.

 

The APs in Etasc started on 1 and 6 (auto assigned) which from what little I know of channelisation should be ok. However as we were having problems I switched them both to manual channel 1 so they were the same as Craven, which are working) but that made no difference in Etasc.

 

A wireless scan using inSSIDer shows no other wlans anywhere in sight.

 

I read up on wireless channelisation to make sure I was reasonably correct in my thoughts, which I was, so I've now manually assigned each pair onto 1 and 6.

 

Does this sound ok?

 

Peter

[Bruce123]

Yes. I don't know about Ruckus WiFi, but "roaming" was part of the original 802.11b standard, which has been around for over 10 years now and works with standard WAPs (they don't even need to be managed).

 

Essentially for client roaming to work each AP:

 

SSID is identical

Encryption type is identical

Key is identical

Channel is different.

 

Ideally each AP should be on a different (and non-overlapping channel*).

 

Otherwise, the radio waves from your APs/clients will interfer with each other, potentially causing problems and slowing performance.

 

The Netgear WiFi Switch that we use has a feature call Automatic Radio Mangement, which automatically configures adjacenet APs to be on different channels.

 

You might also like to try deleting the wireless connection on the laptop you are doing the tests with and set it up again (Windows tends up cache wireless information, which may not be helpful in your tests).

 

I hope that this helps.

 

Bruce.

 

*I can't recall what channels are non-overalpping but 1 and 6 sound OK.

Edited April 10, 2012 by Bruce123

[howartp]

Yes. I don't know about Ruckus WiFi, but "roaming" was part of the original 802.11b standard, which has been around for over 10 years now and works with standard WAPs (they don't even need to be managed).

 

I hope that this helps.

 

Bruce.

Thanks Bruce.

 

1, 6 and 11 are the recommended non-overlapping channels.

 

I think I'm going to factory reset the Ruckus APs and controller, remove all WLAN connections on the clients, and try from scratch.

 

Cheers,

 

Peter

 

ps - I'll try the ping -t first - good thought. Cheers.

Edited April 10, 2012 by howartp
Just noticed Bruce edited his reply whilst I was responding

[DarrenG]

It's also worth running a scan to check there are no networks in surrounding buildings with access points that mat be effecting your network. There are loads of free tools available for this task. If for example you find a network next door on channel 1 then put your 2 aps on 6 and 11. Also what channel width do you have them set to? I would avoid using 40mhz due to overlap