We've discussed this a while ago, but I thought I'd bring it back up again. Here's a recent thread on Small Net Builder http://www.snbforums.com/threads/seamless-roaming-zero-handoff.24525/

Their consensus seems to be that Cisco gets it right, but not so much for consumer grade gear, except maybe new stuff around the corner.

Anyone here agree / disagree?

I ask mainly because I'm pondering a serious home theater upgrade (4K,etc) and one of the curious features of the high end Sony ES receiver, one of the very few receivers that properly deals with the copy protection nonsense of HDMI2/HDCP2.2, also happens to include an eight port gigE switch with PoE, which is remarkably useful to ponder in my space-constrained equipment rack.

Meanwhile, I'll express modest sadness that the new Google OnHub router could /should totally deal with automatic roaming / handoff but doesn't. They've got the bespoke platform. They've got the engineering talent. They just aren't targeting the feature.

Not understanding how this particular thing works into WiFi roaming?

Mostly because I'm about to have PoE and no longer need a switch,allowing me to use a dedicated AP rather than a router with NAT disabled. More choices, I hope.

I am currently testing out these...

https://www.ubnt.com/unifi/unifi-ap/

They do "zero hand off" roaming.

I don't think that model will work for you as stupidly it runs at 24v not 48v.

I read reviews of these things and thought it would help out with slow WiFi in parts of my house. We have a small house but it's 3 levels and there doesn't appear to be one spot that works well for all 3 levels. So far I'm less than impressed. The throughput from them is okish sometimes but mostly poor, and WiFi access seems to lock up sometimes. I haven't decided if I'm keeping them yet. Unlikely at this point.

Cheers

Cris

I've had a couple of Unifi APs for a while now.

I do like them generally and they do give me good coverage over the whole of our house. I don't use the "zero hand off" (ZHO) roaming as the standard roaming works well enough for everything other than Skype.

They aren't perfect though, one of my two APs stops responding on wifi occasionally and I have to restart it.

I have recommended them to other people though and everyone I know who bought them are generally happy.

Our house is about 80 feet end-to-end, two stories with plenty of internal brick walls. I have one on in the ceiling void on the ground floor at one end and the other in an attic at the other end. They cover the whole house very well and also provide decent coverage in the garden within about 40 feet of the house.

I have mine setup without ZHO, so a single ssid but different channels on each AP.

Mine are a pair of the UAP AP-PRO model

https://www.ubnt.com/unifi/unifi-ap/

My MacBook will hit ~120 Mbits/sec when talking to my Unifi AP.

Which is faster than the power-over-ethernet that connects one of my APs to the rest of the network, I really need to run some Ethernet

I should probably say, I am in a very low density wifi signal location. I can't see a single other wifi network from my house

Yeah, I've been using the Unifi product line for a few years now and they've been pretty reliable for me. They also just released a new line of AC access points, so you might want to wait a little until they're more available on Amazon (I think they're on there but not Prime - they also have their older AC APs available).

The Unifi products have worked well in all the businesses and homes I've installed them. So far I haven't heard any complaints, and in many many instances they've greatly helped with poor WiFi coverage. I've had some customers who don't need blazing speed but do need good coverage, and for those I'll attach a Unifi AP to a powerline or MoCA adapter and it works wonderfully.


In my own home, however, I've decided to make a switch. I had a couple very early Unifi APs that weren't the long range models. They were 2.4GHz 802.11n and I wanted to upgrade. I think that anyone here can guess that I upgraded to the OnHub.

I did this for several reasons. The main one was that I hate the Verizon Actiontec routers. The UI is terrible, and they just don't seem to work well. It took quite a bit of work but I have now completely removed it from my network (not advised if you still need guide data or VOD for Fios set top boxes - I don't because I have a Tivo).

The signal on these OnHub units is absolutely no joke. I put this thing in a central location, and I still get a strong signal at the very furthest reaches of my house and property. My beloved WiFi Analyzer app (Android FTW) gives me a reading of -60 to -55 dBm from two floors below and about 20 feet to the side of its current location on top of a dresser. Well within acceptable strength.

I'm also getting absurd speeds. I'm not sure how to test the speed of data transfer between devices inside a network, but I've done an unofficial test using the Plex app on my Nexus 5, and got an extremely high quality video to load instantly.

The configuration of the OnHub is very simple, though the menu system could use some work.

I have a couple complaints:

1- I would also like roaming capabilities for houses larger than mine (there are plenty in my area). It's certainly possible to set up two OnHubs on the same network, but it's certainly not doing was Unifi is doing.

2- No guest network. This is a curious omission. Sometimes I'd just like to have my guests get out to the internet and not see all the systems on my network. This does, however, limit what you're able to do as far as media streamers and other recent entertainment tech. There's probably also a reason that ties into whatever future smart home technology that's supposed to come to the OnHub.

3- This is a weird one, but the OnHub can't route back traffic. If I'm on my own WiFi and I enter my no-ip address so I can see the IP camera that monitors my baby at night, it just won't work. I have to enter the local IP. Port forwarding works, but I thought it didn't for the longest time because of this. As long as I disable the WiFi on my phone, I can use my public IP and the traffic is routed correctly. This is quite annoying because I have to swap camera devices in my IP camera app whenever I leave the house and want to check in. Just a little weird.

So far, though, I'm a big fan (no surprise, I know).

I use iperf:

https://iperf.fr/iperf-download.php

The only thing keeping me from the Unifi products is the need for a central controller. I don't want my WiFi depending on my desktop computer being alive, nor do I want my WiFi depending on some remote cloud service being alive / reachable.

The inevitable alternative, I suppose, is some sort of dual-NIC fanless PC contraption running the firewall, NAT, and all of that. My concern with that is, while it's super flexible and configurable, it's also something that requires care and feeding, versus something like the Google OnHub which just magically updates itself.

In most cases the Unifi controller does not need to be running all the time. You only need it for configuration and if you want to monitor what the APs are up to.

There are some features, like the guest portal I think, that need the controller running.

I thought you needed the controller to manage the hand-off between APs. If not, then that radically changes my thoughts on the Unifi solution.

EDIT: Hello all-in-one solution-in-a-box!
http://www.amazon.com/Ubiquiti-Unifi-Security-Appliance-USG/dp/B00LV8YZLK
https://www.ubnt.com/unifi-switching-routing/usg/

You can run this box as your firewall/NAT/gateway, then add on a switch (with or without PoE) and some Ubiquiti base stations. Interesting.

EDIT 2: The Amazon reviews give me more than a moment of pause. Like this:

I think you may possibly need the controller on if you are using the zero-hand-off stuff. But you shouldn't typically need that, for most clients at least.

From what I've seen the advice is not to use ZHO unless you really can't make your setup work without it. I suspect it is a bit of hack and I don't think they've even supported it on the AC APs.

Normal roaming is very fast for me, Skype calls don't drop on my iPhone for example. You do sometimes need to tweak the power settings though, some people have to turn down the power to make hand off work well, which is non intuitive. Basically if your wifi footprint between APs overlaps too much you don't get good roaming behaviour. I luckily get away with leaving the power on my APs on auto.

The overlap issue isn't a Unifiy specific issue.

Posts on the Unifiy forums say that the controller doesn't even need to be on for ZHO, the APs manage things once configured.

There is also this:

"People seem to confuse "seamless" roaming with "zero handoff" feature. ZHO is only really needed if you must support sensitive applications that could not survive a normal, or natural handoff, like VOIP for example. That absolutely does not means, that without ZHO you can't have a seamless roaming between APs, it's really the opposite, when walking around, users will hardly notice their devices have reconnected to the network, and are now talking to a different(hopefully near) AP."

Like I said, most people don't need ZHO anyway. And in my experience things like Skype can survive a natural roam between my APs.

Ubiquti have definitely be guilty at times of releasing products before they are 100% ready with the software. At this point the AP code and the controller, even the new version, feel fairly robust to me.

Zero Handoff Roaming only really works in very specific environments. The way it works is by having all of the APs on the same channel and spoofing data to appear as if it is coming from the previous AP. The APs figure this all out by communicating with each other over an encrypted connection on the LAN. Anyway, basically it only works when your APs are the *perfect* distance apart to avoid serious channel congestion, interference and poor performance. Honestly it is a PITA to get right and I would avoid it like the plague.

With normal setups it is the client itself which is the device that decides to move from one AP to another. A decent client will typically switch networks in around 500ms and this shouldn't really affect anything bar maybe a blip in SIP VoIP.

It is true that historically Ubiquiti have released some products before they are ready. Don't touch the USG. The v1 UAP-AC was also a fairly terrible product (the current UAP-AC v2 is not bad). The UVP phones are a little raw at the moment software-wise.

On the flip side the UAP-PRO is a great piece of kit, and the plain vanilla UAP is amazing value for money in rural situations where 2.4GHz is not congested. Don't bother with the UAP-LR as it really doesn't offer anything over the UAP. Personally, I find the software controller to be reliable. It is not the best designed thing, but it does work well.

Yes, the UAP products I mentioned are EOL. The new generation of UAPs are all AC. They all have their merits - the UAP-AC-LITE is really quite cheap for what it is and a good unit for low bandwidth use with its 2x2:2 setup on both channels. The UAP-AC-LR has a sweet high performance antenna and is a great little product (as opposed to the first gen UAP-LR). The LR also does 3x3:3 on 2.4GHz which is nice. The UAP-AC-PRO does 3x3:3 on both bands, 802.3at PoE and a second ethernet port. Personally I think it is a shame that the PRO doesn't support yet more streams.

The new APs promise a spectrum analysis feature through the remote controller and this is a real game changer for me. I have (beta) samples of these which I've been testing and so far they have been solid.

Also, 24V Passive PoE - this is common for WISPs and something you will also find on Mikrotik gear. Still, they should really get with the program and put their indoor stuff on 802.3af/at.

I echo everything that Andy has said here. I have never had an issue with handoff between Unifi APs. Even when I was using Voip through Google Voice/Hangouts, my calls wouldn't drop even though I could see the signal dropping and rising as I walked from one AP to the other.

So no, a controller isn't needed. I didn't have one running for the two years I ran my Unifi system.

Of course, if I wanted a guest portal where I charged weekend visitors for internet access, then I'd definitely need the controller to be running...

Cisco roaming works and is amazing (so long as you have a Cisco WLAN adapter in your device and drivers that support that feature).

So let me back up a step and talk about what's not working in my home. I've got two Apple Airport Extremes (the most recent 802.11ac version). One is upstairs, in a corner closet, where all the home wiring comes together and acts as my router/gateway/NAT box. I've got a hardwired Ethernet cable going from that down to my home theater, in the opposite corner of the house. The second Airport is there, next to the television, acting as a dumb switch for all the home theater gear, and bathing the area in front of the TV in WiFi.

My observation is that 2.4GHz does penetrate the whole house, but 5GHz doesn't get anywhere close to this. Since we tend to use our devices while sitting around the TV, it's therefore really important to have the base station right next to the TV.

What will happen with my Android phone (Nexus 5 running the latest CyanogenMod 12.1) is that I might be upstairs and it will be latched onto that base station. Then I head downstairs and I'm sitting next to the TV. It's still desperately clinging to the upstairs base station, even though it has a much better base station sitting just feet away. If I disable and reenable WiFi, it will only then notice it's got a stronger alternative and latch onto the adjacent base station.

(They're configured with the same SSID, same WPA2 credentials, etc.)

At least at the TCP/IP layer, my phone will maintain the same IP address no matter where it's connected, since the downstairs AP isn't running any sort of NAT -- it's configured to be just a dumb switch -- so if my phone would only switch APs, then there would hypothetically be no application-layer disruptions of service.

Based on this, I've (perhaps erroneously) concluded that my problem is that my base stations need to be more engaged in managing my phone. I'd like the downstairs AP to see me and say "hey, this device needs to be paired with me, not the AP upstairs". Then they'd send me the magic WiFi packets to kick me off and make me rejoin the network.

Right... given all that, the question is whether my problem is that Android is just being dumb or whether I need "zero handoff roaming" or "seamless roaming" or something else entirely.

Bugs against Android OS seem to point to it being a problem specific to the Android platform. Finger pointing at Linux or the hardware in these threads but no solid solutions.
https://code.google.com/p/android/issues/detail?id=12649
https://code.google.com/p/android/issues/detail?id=74990

Some people claim success with this: https://play.google.com/store/apps/details?id=com.heleron.wifiroamingfix

Odd that Android and Linux didn't fully implement the 802.11 based roaming standards. (802.11r being one of them). Back at my old house in 2003, had roaming going between two Airport Expresses situated at each major area similar to your setup Dan. Though back then, both Airport Expresses simply handled WiFi, and no NAT or routing at all.

Really? Like seriously really? It's just a dumb bug in my damn phone that other phones/platforms get right as a matter of course?

Hmm... I know that Android M(arshmallow) has a bunch of new sophistication in this area, primarily dealing with switching from cellular to WiFi networks and avoiding "poor connections". Maybe the handoff that I want will be baked into newer Android builds and I don't need to buy new hardware at all. Hmm.

EDIT: Huzzah! Need to try this! https://play.google.com/store/apps/details?id=com.heleron.wifiroamingfix

I don't know, I've seen this kind of behavior in all manner of WiFi devices over the years. I assumed that this was because the two access points, while sharing a name and password, aren't doing any work to create a mesh network. That's what I thought was different about the Unifi products, that the APs were doing some work to hand off devices as well as the clients themselves knowing when to swap.

That "WiFi Roaming Fix" app seems to be working so far for me, on campus. As I sit here in my office, it reports that it sees 9 APs, and it's presumably configured me on the strongest one. Historically, I've had all sorts of failures if I'm doing something like typing in a text message via some app or other while walking between buildings. Maybe this will help? We'll see.

Yes, hanging on to the wrong AP is a typical device problem - it is up to the client to scan in the background and make its own decisions.

Ubiquiti Unifi does have an option called minRSSI which allows you to set a minimum signal level of a client. If it goes under that value, the device will be disconnected from the network, essentially triggering a kick where hopefully the client will figure itself out. However, it is entirely possible that when this happens the client will just reconnect back to the AP that it was previously on. Sometimes WiFi drivers are stupid. The Unifi AP will not kick a device twice in the same session.

My laptop does this in Linux, always hanging on to my AP upstairs when I go down or vice versa. In Windows, it works perfectly and seamlessly.

In the future 802.11r and 802.11k will hopefully solve these issues once and for all one day.

I'm considering getting one of those Google wifi hubs merely because our home network can't ever seem to deal with our Chromecasts properly. We keep having to reboot the chromecast that we want to watch (we have two) before either of them will show up in the list of available chromecasts on our smartphones. I'm wondering if Google's own access points will handle their own chromecasts properly. :-)

Chromecast: mine is about two feet away from my Airport Extreme, but those feet are vertical and I'm sure the antennae of the Airport are pointing horizontally. Net effect is a lot of flakiness. A non-trivial part of my home theater upgrade plan is to have everything connected to wired Ethernet. The only way to get Chromecast functionality with a wired Ethernet jack is currently a television from Sony. The "Nexus Player" is WiFi only. (Grrr.)

WiFi Roaming Fix: now disabled. It totally thrashes on campus, where there may be 6-9 Cisco APs within radio range, and Cisco is (presumably) doing its own fancy management of my broken Android phone. Internal management + Cisco management = serious problems.

802.11r / 802.11k: Ahhh.... So the real solution to my problem is "just wait until the standards get implemented, debugged, and revved".

I don't know much about those things, but if Chromecast can also work from an Android device, then many such boxen will connect over wired GigE with a USB Ethernet dongle connected via an OTG adapter.

Cheers

Sadly, no, Chromecasts are their own thing, running some non-Androidness on the inside.

Dan: You'll like this - https://store.google.com/product/_ethernet_adapter_for_chromecast