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Posts: 3
Registered: ‎05-29-2016
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Totally confused --> user zero handoff or 802.11R?

Hello,

 

I was about to purchase some Ubiquiti access points (Unifi AP), planning to use Zero Handoff. Why? It is a home situation (4 floors, concrete structure): I currently use the ISP modem/router with built-in Wifi AP and additionally a 2.4GHz el cheapo AP. Both in a different SSID, because our Apple devices just won't switch to the strongest AP anyway and this makes it easer to manually switch over.

We need an additional AP, since the 2 current APs just won't cover the whole house. That would introduce a third network and even more switching over :-(.

So I want a Wifi network that does not require the users to switch over manually each time.

 

The idea was to use Zero Handoff (ZH), since that would solve my issue. However, the forum discussions suggest that I should avoid ZH if at all possible.  So I could use 802.11k/r/v instead. According to Apple, iPhone 4S / iPad 3 do support 802.11r, but I am not sure of Android olders phones (Android 4.0-ish).

 

All PC are on the wired LAN. The Wifi traffic in the house is not heavy, mainly whatsapp, some browsing, maybe some music, but nothing heavy and max a handful of clients (which makes me think that single channel / ZH might be OK, but I also read that ZH is a temp 'project' meant as an intermediate solution).

 

Any advice would be highly appreciated:

1 - YES / NO Zero Handoff?

2 - Can I use Unify AP and / or Unify AC AP Lite?

3 - Do I need some box between the Wifi network and the ISP NAT router?  I would like to have a guest network that only connects to internet, not to my LAN equipment, but that is not essential.

4 - I DO want (near-) seamless roaming

 

 

Many thanks for any hints.


Accepted Solutions
SuperUser
Posts: 4,245
Registered: ‎01-05-2012
Kudos: 1152
Solutions: 529

Re: Totally confused --> user zero handoff or 802.11R?

1) No
2) AC Lite
3) Edge Router Lite or X, plus Tough switch 5P, Guest SSID on its own dedicated van
4) Fine tuning of Tx power, correct channel selection and minRSSI will help you.
Cheers

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Regular Member
Posts: 490
Registered: ‎02-13-2014
Kudos: 283
Solutions: 13

Re: Totally confused --> user zero handoff or 802.11R?

[ Edited ]

Zero Handoff is almost always the wrong way to go except for a few very specific circumstances. For a household with multiple access points, I would strongly advise against it for a number of reasons, the most important being that it makes all access points work as one unit, and more importantly, on the same channel. This is bad for capacity and performance, but good for low-bandwidth devices that NEED to roam completely seamlessly, such as wifi VoIP phones.

 

You've uncovered a "problem" in the way wifi was designed, and that is the fact that devices will stay connected to an access point unless they encounter a problem with it, and that means they won't notice a stronger access point that you've moved closer to.

 

The answer, in most cases, is to enable and configure a setting called "min rssi". The Minimum RSSI setting basically tells an access point, "Hey, if a device connects to you and their signal gets too weak, actively kick them off". When this happens, the device will instantly try to reconnect to the strongest access point it can see. This happens -almost- instantly, and in many cases isn't even noticed.

 

Without this, devices will stay connected to the first access point until they get far enough away that communication isn't possible -- even if they're now right next to a good, strong access point.

 

There's no universally correct setting for min rssi, because every environment is different, but I would advise to start with -80 or -70 and see how it works and report back.

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All Replies
SuperUser
Posts: 4,245
Registered: ‎01-05-2012
Kudos: 1152
Solutions: 529

Re: Totally confused --> user zero handoff or 802.11R?

1) No
2) AC Lite
3) Edge Router Lite or X, plus Tough switch 5P, Guest SSID on its own dedicated van
4) Fine tuning of Tx power, correct channel selection and minRSSI will help you.
Cheers
New Member
Posts: 3
Registered: ‎05-29-2016
Kudos: 1

Re: Totally confused --> user zero handoff or 802.11R?

Thanks for the clear answer!

SuperUser
Posts: 12,010
Registered: ‎10-06-2013
Kudos: 3791
Solutions: 916

Re: Totally confused --> user zero handoff or 802.11R?

1) There is no ZHO on UniFi AC. Happily.

UK Comms & Links Engineer.


Come on you lot, Feel free to 'Mark as Solution' At least click the Kudos button. Thanks.


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Highlighted
Regular Member
Posts: 490
Registered: ‎02-13-2014
Kudos: 283
Solutions: 13

Re: Totally confused --> user zero handoff or 802.11R?

[ Edited ]

Zero Handoff is almost always the wrong way to go except for a few very specific circumstances. For a household with multiple access points, I would strongly advise against it for a number of reasons, the most important being that it makes all access points work as one unit, and more importantly, on the same channel. This is bad for capacity and performance, but good for low-bandwidth devices that NEED to roam completely seamlessly, such as wifi VoIP phones.

 

You've uncovered a "problem" in the way wifi was designed, and that is the fact that devices will stay connected to an access point unless they encounter a problem with it, and that means they won't notice a stronger access point that you've moved closer to.

 

The answer, in most cases, is to enable and configure a setting called "min rssi". The Minimum RSSI setting basically tells an access point, "Hey, if a device connects to you and their signal gets too weak, actively kick them off". When this happens, the device will instantly try to reconnect to the strongest access point it can see. This happens -almost- instantly, and in many cases isn't even noticed.

 

Without this, devices will stay connected to the first access point until they get far enough away that communication isn't possible -- even if they're now right next to a good, strong access point.

 

There's no universally correct setting for min rssi, because every environment is different, but I would advise to start with -80 or -70 and see how it works and report back.

New Member
Posts: 3
Registered: ‎05-29-2016
Kudos: 1

Re: Totally confused --> user zero handoff or 802.11R?

I decided to forget about ZHOFF, based on what I read. Will probably try RSSI settings once I purchased devices.

Thanks for saving me from buying the wrong devices!

Regular Member
Posts: 490
Registered: ‎02-13-2014
Kudos: 283
Solutions: 13

Re: Totally confused --> user zero handoff or 802.11R?

[ Edited ]

If you already have a NAT router from your ISP, you wouldn't -need- another router. Just note that Access Points don't do any routing - they simply bridge your wired and wireless networks, so you do need -a- router if you're just being provided a single public IP address from your ISP.

 

Unifi itself has some Guest features built in that allow you to create a guest network that's isolated from your primary network. You could use the router you already have and keep things simpler, or use an EdgeRouter, Unifi Security Gateway, Mikrotik router, etc.

 

You can take that further by using VLANs to provide even more isolation and control, though your ISP router likely doesn't support this.This is absolutely not necessary, but can provide a few perks if you know enough to do it. If not, don't worry about it.

 

Definitely try to avoid any wireless-uplink situations where an access point connects back to your network -using- wireless. If you can hardwide all access points, you'll be far better off.

 

Any Unifi devices, from the standard older UAP to the newest AC access points, should be just fine for what you need to do -- especially considering you don't have heavy requirements/utilization.

Regular Member
Posts: 379
Registered: ‎02-16-2016
Kudos: 142
Solutions: 9

Re: Totally confused --> user zero handoff or 802.11R?

There are hints from Devs that they're working on 802.11r/k/v - if it arrives, it will solve a lot of your headaches.

 

As of right now, minRSSI will help you, but it's a dirty hack, and may cause you trouble, particularly if you have people that think (say) a -80dBi connection is good enough and can't get anything else in that "corner" of the house. Apple devices in particular don't like minRSSI, particularly if you configure a number that is too high. 

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