Seamless AP Roaming

azzeretti

Does anyone have any good config options (or advice) on installing multiple APs with the same SSID to enable seamless AP roaming? Ordinarily I would drop in a controller of some sort but I can't in this case. I have a site with 8 APs and they all have the same SSID. Some clients are not switching AP and instead are staying connected to the first AP they connect to. This means, as they move, the signal drop too much and the connection dies.

I have the APs (11g/n) using different channels, same SSID, all connected in AP mode back to a central switch. However, some devices still hold on to the lower signal AP when moving around. I can swap out the APs but I am not certain that the issue is an AP issue or a client roaming issue.

Anyone any ideas or thoughts ?

Alun

Many wireless drivers (PC based ones at any rate) allow you to set parameters that change the roaming behaviour. Usually called Roaming Policy, Roaming Sensitivity, Roaming Aggressiveness or something like that. You can even turn roaming off completely in some cases. So it might be worth looking at these settings if possible. Mobile devices like phones and tablets will generally offer less configurability in this regard though I think.

azzeretti

Alun wrote: »

Many wireless drivers (PC based ones at any rate) allow you to set parameters that change the roaming behaviour. Usually called Roaming Policy, Roaming Sensitivity, Roaming Aggressiveness or something like that. You can even turn roaming off completely in some cases. So it might be worth looking at these settings if possible. Mobile devices like phones and tablets will generally offer less configurability in this regard though I think.

Yeah, this is my problem. I have no control over the myriad of clients that might connect. It seems the 802.11n spec doesn't allow for roaming. So, some vendors implement it, others don't. Nightmare for me!

its fukt

It's most likely down to the device. On an Access Point there is a signal threshold, where at this signal limit (say -85db) a deauthenticate frame is sent to the device telling it to look for another AP. It's then up to the device and the device driver to look for another AP with a better signal. WiFi controllers and some AP's allow you to control this limit setting, see if you have it, could lower it to see if you get better results

This will always be an issue unless you opt for a better system like Ubiquiti which offers zero handoff. This is where the AP's act as a single device so clients aren't disconnected, but seemlessly passed from one AP to the other. If done right the migration can be as little as a single dropped ping making it perfect for VoIP.
https://community.ubnt.com/t5/UniFi-Frequently-Asked-Questions/UniFi-What-is-Zero-Handoff/ta-p/412719
http://www.ubnt.com/unifi
(note: the new UniFi AC doesn't support zero handoff yet, all other UniFi's do)

azzeretti

its fukt wrote: »

https://community.ubnt.com/t5/UniFi-Frequently-Asked-Questions/UniFi-What-is-Zero-Handoff/ta-p/412719
http://www.ubnt.com/unifi
(note: the new UniFi AC doesn't support zero handoff yet, all other UniFi's do)

Interesting. Will these APs work alone. That is, with an controller?

its fukt

azzeretti wrote: »

Interesting. Will these APs work alone. That is, with an controller?

There is no controller, its a software controller. You install it on a pc on the same subnet but it's only required for easy initial configuration, the AP's work away fine after without it once configured. The software gives great statistics and detailed logs so it's best keep it running if you can, it doesn't use much resources.

azzeretti

its fukt wrote: »

There is no controller, its a software controller. You install it on a pc on the same subnet but it's only required for easy initial configuration, the AP's work away fine after without it once configured. The software gives great statistics and detailed logs so it's best keep it running if you can, it doesn't use much resources.

This sounds like what I need! Have you much experience with them? Do they roam well? I don't need the controller (there will be no PCs on the wireless VLAN, and it'd be best kept that way!) Any AP model recommendations or do they all roam well?

its fukt

azzeretti wrote: »

This sounds like what I need! Have you much experience with them? Do they roam well? I don't need the controller (there will be no PCs on the wireless VLAN, and it'd be best kept that way!) Any AP model recommendations or do they all roam well?

I've used lots of Ubiquiti products, but used them on two jobs before, one with Zero Roaming and another time I mistakenly bought the AC ones which doesn't support it yet but the devices migrate fine (fairly new Motorolla handhelds). If it were me I'd run the software, when you see it you'll realise why, it gives you so much information and allows so much control. Google for some YT vids and download it to try it out.

The ones to choose depends on the size of the area you want to cover, remember these things are really powerful so you may end up needing less APs than before. The UAP covers 400ft radius, UAP LR (long range) 600ft or the Pro version does 400ft. They really need to be ceiling mounted for best coverage.

its fukt

This is the best place to get them, if you're registered for VAT they will ship them without VAT

http://www.interprojekt.com.pl/ubiquiti-airmax-unifi-c-108_182.html

Alun

its fukt wrote: »

It's most likely down to the device. On an Access Point there is a signal threshold, where at this signal limit (say -85db) a deauthenticate frame is sent to the device telling it to look for another AP. It's then up to the device and the device driver to look for another AP with a better signal. WiFi controllers and some AP's allow you to control this limit setting, see if you have it, could lower it to see if you get better results

Can the devices themselves not initiate roaming too? I always thought this was the way it worked, otherwise what would be the point of the various settings available on many drivers?

its fukt

Alun wrote: »

Can the devices themselves not initiate roaming too? I always thought this was the way it worked, otherwise what would be the point of the various settings available on many drivers?

Yes, devices can also seek a better APs but most don't really give that many configurable options. YMMV with a mixture of devices.

There are apps in the Google Play store that force WiFi to check and change to the strongest AP on an interval, not sure about iOS, I don't have one.
https://play.google.com/store/apps/details?id=com.pintacdesign.bestwifi

azzeretti

Turns out the Unifi APs don't allow Zero Handoff with an open SSID, only secure ones. Wish the tech spec said that before I purchased 3 of them!

On the up site, they're a great piece of kit and hopefully I sort something by TX settings.

mocata

I will give you a fair price for them if they turn out not to be fit for your job

notnumber

azzeretti wrote: »

Turns out the Unifi APs don't allow Zero Handoff with an open SSID, only secure ones. Wish the tech spec said that before I purchased 3 of them!

On the up site, they're a great piece of kit and hopefully I sort something by TX settings.

Why is that a problem?

azzeretti

notnumber wrote: »

Why is that a problem?

Why is not having Zero Handoff on non-secure networks a problem? Because the solution is for an open wireless solution in a public area where handing out passphrases would be impracticle.

Or do you mean why would setting TX parameters and RSSI thresholds be a problem?

notnumber

azzeretti wrote: »

Why is not having Zero Handoff on non-secure networks a problem? Because the solution is for an open wireless solution in a public area where handing out passphrases would be impracticle.

Or do you mean why would setting TX parameters and RSSI thresholds be a problem?

Oh Ok you need an open network .....much time is often wasted setting up cells and overlaps these AP sound great am definitely gonna trial them.