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How to setup two UniFi AC-Pro devices?

[ Edited ]

I have bought two UniFi AP-AC Pro's, UniFi 8 Port Switch and a UniFi Cloud Key.  For my initial setup I wired each UniFi AP-AC-Pro with it's own ethernet cable and it worked very well indeed.  However, I gave each AP the same name KAY (which they accepted) and they produced 2G and 5G signals on different channels i.e 6,11, 36 and 44. I wandered around my large home with my tablet and connected to KAY easily.  However, once set to KAY in my first room, wherever I went I stayed on the initial channel despite the fact that a different channel had a better signal.  To connect to the better signal I simpy chose a different channel on my tablet.  Obviously this is OK but somewhat inconvenient.  Accordingly, I then disconnected one AP from the Switch and wired it to the Bridge port of the other AP.  This worked and, more importantly, I then got KAY with only channels 6 and 44 and my aforementioned inconvenience was gone; I always got connected to the strongest signal but the signal was weaker that before - perhaps the bridged AP was not working after all?

 

My question is this.  Have I connected my two AP's correctly? In essence, is there a better way?

 

Any help would be greatly appreciated.


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Re: How to setup two UniFi AC-Pro devices?


@parr wrote:

@Chevalier wrote:

The lowest signal strength that I have measured is -56dB and this is confirmed when I interogate my UniFi Cloud Key.  However, some (not all) of my devices lock onto, and stay with, a particular channel (i get channels 1,6,36 and 44 when the AP's are set to Auto) when I know a different channel gives -36dB.  


-56 is a pretty strong signal, so of course your devices aren't wanting to roam yet. Whether to roam or not is determined by the client. If it has a strong connection it may not be scanning other networks to look for a place to roam since it has what it considers a nice stable connection.

 

If you want the devices to roam between the APs, you will need to set the power levels lower so that the clients see a lower RSSI and decide to roam. This will be the case whether you use the same or different channels on your APs.


I have now completed two experiments.  One witht he AP's set to the same channels and the other where the AP's choose the channels automatically.  I got some interesting results,  Where the AP's are on identical channels everything worked fine but I did get the occassional conflicts.  The second experiment when the AP's were set to Auto everything worked well too and I got no conflicts.  Roaming did not seem to work until I had the friends over.  Then I found that the AP's automtically adjusted channels to find the best vailable and so I established clearly that setting AP's to Auto is clearly the best solution.

 

I would like to thank everyonefor contributing to this fascinating debate resulting in a solution.

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Re: How to setup two UniFi AC-Pro devices?

As I understand it, the APs get their SSID from the Wireless network information in Settings. 

 

The names you gave the APs are just Aliases. You must have also called the SSID on the wireless network "KAY", is that correct?

 

You should definitely leave the APs connected directly to the switch. I'm fairly sure that by connecting them in series with the pass-through port you are limiting the network capacity to both the APs. 

 

As for forcing the client into specific bands, I wouldn't get too hung up on the strongest signal. The APs seem to be pretty good in my experience at managing the best channel given all the prevailing factors in the area where they are located. This can include other 2.4Ghz devices that are generating RF noise, other WiFi networks nearby etc. I recently discovered that I was drowning out my neighbour's WiFi by forcing my APs onto High transmit power. I effectively have an AP in every room in the house and I had no need for High transmit power but I had a bit of a Tooltime moment and turned them all up to 11. It subsequently transpired that I actually got the best speeds in my own place by having everything set to low power and letting the APs pick their own bands. 

 

Try it all on Auto and see what happens. The important thing surely is your network user experience, not forcing your client into the strongest signal. 

 

 

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Re: How to setup two UniFi AC-Pro devices?

[ Edited ]

Many thanks for your response.  You are correct that I have set the SSID as KAY and the AP's have chosen channels themselves.  I also have the power set to Auto on both AP's.  In the light of what you have said, it is clear that I should keep the ethernet cable from the switch to each AP rather than loop from one AP to the other.

 

Incidentally, I was not forcong the AP's to a different channel.  I was forcing my mobile device to move to a stronger channel rather than remain on the weak channel - I thought that it would do this automatically but apparently not.

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Re: How to setup two UniFi AC-Pro devices?

The AUTO channel/power function of the AP's is not really that good. Do not use it.

Do an RF scan and then manually set both AP's to a different channel.

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Re: How to setup two UniFi AC-Pro devices?

In addition to the above mentioned to make sure you are using suitable channels, in my deployments over the years of multiple APs to extend network coverage I have always used the same channels on 2.4GHz and 5GHz for all APs in the network.

 

There has always been a debate about whether or not you should use the same channel because if the APs are too close they will interfere with each other similarly to if they are too far you have defeated the purpose of adding more APs.

 

I have a rather large home myself with multiple AC-HDs and AC-Pros now deployed and have gotten roaming to work mostly seamless but it takes surveying through RF scan, setting minimum RSSI depending on the AP, etc. to deploy multiple APs.

 

You should never use Auto.

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Re: How to setup two UniFi AC-Pro devices?

Thank you.  I have done an RF scan already and found that my manual assessment is the same as UniFi system.

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Re: How to setup two UniFi AC-Pro devices?


@AvalonDanvers wrote:

In addition to the above mentioned to make sure you are using suitable channels, in my deployments over the years of multiple APs to extend network coverage I have always used the same channels on 2.4GHz and 5GHz for all APs in the network.

 

There has always been a debate about whether or not you should use the same channel because if the APs are too close they will interfere with each other similarly to if they are too far you have defeated the purpose of adding more APs.

 

I have a rather large home myself with multiple AC-HDs and AC-Pros now deployed and have gotten roaming to work mostly seamless but it takes surveying through RF scan, setting minimum RSSI depending on the AP, etc. to deploy multiple APs.

 

You should never use Auto.


I too wondered whether the two AP's should be manually set to the same channels.  In my case Channels 6 and 44 are the best (not used by anyone else near to me) so I shall do that and see what happens.  Many thanks for your response.

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Re: How to setup two UniFi AC-Pro devices?

You shouldn't need them on the same channels, and while it may work, technically the APs will cause interference with each other if they are set to the same channels. In very large deployments, or really any with more than 3 APs, you will have to have some APs on the same channels, but often you lay them out so that they have other APs in between them.

 

What kind of devices are you using? Can you check the signal strength of the client? For instance if you have a Mac computer, you can option click on the WiFi icon in the menu bar and it gives you the channel, RSSI level, and a lot of other details. Apple devices will attempt to roam when they hit -70 RSSI.

 

If you can get an idea of the signal level your clients are seeing, you can then start playing with the power settings for the radios so that you can get clients to hand off between the APs when you want them to. In my deployment I have 5Ghz set to high, and 2Ghz set to medium on 2 APs and low on the 3rd.

 

FYI, the auto power settings for the radios always set them at high, which is often not the correct level for a multi AP deployment.

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Re: How to setup two UniFi AC-Pro devices?


@AvalonDanvers wrote:

 

 

You should never use Auto.


I'm going to respectfully disagree. NEVER is a very sweeping statement. In fact, I think AUTO works just fine in most environments. With the exception of the power setting defaulting to HIGH the channel separation and selection works very well on AUTO. 

 

And, as the OP discovered, AUTO gave the same results as the site survey in that case (and all four of my systems too).

 

While configuration of every minor detail is possible in Unifi, the AUTO features are there for a reason, and they do a reasonable job of optimising the WiFi in my experience. 

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Re: How to setup two UniFi AC-Pro devices?


@parr wrote:

You shouldn't need them on the same channels, and while it may work, technically the APs will cause interference with each other if they are set to the same channels. In very large deployments, or really any with more than 3 APs, you will have to have some APs on the same channels, but often you lay them out so that they have other APs in between them.

 

What kind of devices are you using? Can you check the signal strength of the client? For instance if you have a Mac computer, you can option click on the WiFi icon in the menu bar and it gives you the channel, RSSI level, and a lot of other details. Apple devices will attempt to roam when they hit -70 RSSI.

 

If you can get an idea of the signal level your clients are seeing, you can then start playing with the power settings for the radios so that you can get clients to hand off between the APs when you want them to. In my deployment I have 5Ghz set to high, and 2Ghz set to medium on 2 APs and low on the 3rd.

 

FYI, the auto power settings for the radios always set them at high, which is often not the correct level for a multi AP deployment.


My devices are Samsung mobile phones, Tablets and TV's.  I also have Windows 10 PC's and an Amazon Fire Stick.  The lowest signal strength that I have measured is -56dB and this is confirmed when I interogate my UniFi Cloud Key.  However, some (not all) of my devices lock onto, and stay with, a particular channel (i get channels 1,6,36 and 44 when the AP's are set to Auto) when I know a different channel gives -36dB.  So that this my issue.  Somone else on this forum told me to set both AP's to the same channels because he found that worked for him.  Now you tell me not to that because they will interfere - now I have conflicting advise.  I suppose the only way to resolve this issue is to try both AP's on the same channels and see which advice is correct.

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Re: How to setup two UniFi AC-Pro devices?


@Chevalier wrote:

@parr wrote:

You shouldn't need them on the same channels, and while it may work, technically the APs will cause interference with each other if they are set to the same channels. In very large deployments, or really any with more than 3 APs, you will have to have some APs on the same channels, but often you lay them out so that they have other APs in between them.

 

What kind of devices are you using? Can you check the signal strength of the client? For instance if you have a Mac computer, you can option click on the WiFi icon in the menu bar and it gives you the channel, RSSI level, and a lot of other details. Apple devices will attempt to roam when they hit -70 RSSI.

 

If you can get an idea of the signal level your clients are seeing, you can then start playing with the power settings for the radios so that you can get clients to hand off between the APs when you want them to. In my deployment I have 5Ghz set to high, and 2Ghz set to medium on 2 APs and low on the 3rd.

 

FYI, the auto power settings for the radios always set them at high, which is often not the correct level for a multi AP deployment.


My devices are Samsung mobile phones, Tablets and TV's.  I also have Windows 10 PC's and an Amazon Fire Stick.  The lowest signal strength that I have measured is -56dB and this is confirmed when I interogate my UniFi Cloud Key.  However, some (not all) of my devices lock onto, and stay with, a particular channel (i get channels 1,6,36 and 44 when the AP's are set to Auto) when I know a different channel gives -36dB.  So that this my issue.  Somone else on this forum told me to set both AP's to the same channels because he found that worked for him.  Now you tell me not to that because they will interfere - now I have conflicting advise.  I suppose the only way to resolve this issue is to try both AP's on the same channels and see which advice is correct.


@Chevalier

 

Both pieces of advice are "technically" accurate. For me, I said if the APs are too close to each other they will cause interference likewise if they are too far from each other you have defeated the purpose of multiple APs.

 

To get around this, particularly in locations that are relatively small environments, people use different channels on the APs to avoid the factor from interference if you don't get to the "nitty-gritty" settings. However, this does usually result in something I've seen over the years which you are seeing: some devices won't lock on to the new channel during roam which does cause issues.

 

Similarly, you will find contradicting advice about the "AUTO" function as you have here. "AUTO" doesn't always line up with the perfect channel but it does always default transmit power to "HIGH" which isn't always what you need.

 

As outlined by Apple, Macs and other Apple devices will roam at -70 RSSI. Other devices have differing settings for when to roam. Minus my ASUS PCI-E WiFi cards, Apple devices seem to always have the best signal strength to any AP so it's a good starting point. Remember, you don't want excessive roaming but you do want the devices to roam as the other AP becomes the one with better signal.

 

As for locking on to a new channel, that's a "your milage may vary" situation - some devices will lock on to a new channel in roam but a lot more don't in my experience. Others may have had differing experiences - it's why the WiFi channel selection has been a debate for many years.

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Re: How to setup two UniFi AC-Pro devices?


@Chevalier wrote:

The lowest signal strength that I have measured is -56dB and this is confirmed when I interogate my UniFi Cloud Key.  However, some (not all) of my devices lock onto, and stay with, a particular channel (i get channels 1,6,36 and 44 when the AP's are set to Auto) when I know a different channel gives -36dB.  


-56 is a pretty strong signal, so of course your devices aren't wanting to roam yet. Whether to roam or not is determined by the client. If it has a strong connection it may not be scanning other networks to look for a place to roam since it has what it considers a nice stable connection.

 

If you want the devices to roam between the APs, you will need to set the power levels lower so that the clients see a lower RSSI and decide to roam. This will be the case whether you use the same or different channels on your APs.

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Re: How to setup two UniFi AC-Pro devices?


@parr wrote:

@Chevalier wrote:

The lowest signal strength that I have measured is -56dB and this is confirmed when I interogate my UniFi Cloud Key.  However, some (not all) of my devices lock onto, and stay with, a particular channel (i get channels 1,6,36 and 44 when the AP's are set to Auto) when I know a different channel gives -36dB.  


-56 is a pretty strong signal, so of course your devices aren't wanting to roam yet. Whether to roam or not is determined by the client. If it has a strong connection it may not be scanning other networks to look for a place to roam since it has what it considers a nice stable connection.

 

If you want the devices to roam between the APs, you will need to set the power levels lower so that the clients see a lower RSSI and decide to roam. This will be the case whether you use the same or different channels on your APs.


I have now completed two experiments.  One witht he AP's set to the same channels and the other where the AP's choose the channels automatically.  I got some interesting results,  Where the AP's are on identical channels everything worked fine but I did get the occassional conflicts.  The second experiment when the AP's were set to Auto everything worked well too and I got no conflicts.  Roaming did not seem to work until I had the friends over.  Then I found that the AP's automtically adjusted channels to find the best vailable and so I established clearly that setting AP's to Auto is clearly the best solution.

 

I would like to thank everyonefor contributing to this fascinating debate resulting in a solution.

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Registered: ‎04-17-2018

Re: How to setup two UniFi AC-Pro devices?

Is the Two AP wired directly using 802.3af or are you bridging from one AP to another. I currently have Two UAP-AC-Pro wired separately going to a switch and would like the two AP's Mesh so that the employees do not have to switch over to another SSID to connect if they are in range of a stronger signal. The new UAP-AC-Pro don't come with a PoE injector anymore. Any help or suggestions would be greatly appreciated. Thank You!