Having issues with APs suddenly becoming slow and almost unresponsive

[rbn]

I have been fighting this for so long, I dont know what to do.

I have several sites running FGT and FAPs. Yesterday I made the desition to TFTP new firmware on all the FAPs and FGTs to see if a clean start can fix the problem. The thing is. The setup can work fine, and then all the sudden the speed is terrible. I go inside the FGT and check  SNR and stuff like that and everything looks great, but it is not. Once this client had this problem and I tried to change a setting in the AP profile, and after that, poof  everything was fine again. 

Another client reboots the FAP when it is to slow and all the sudden everything is fine again. So it does seem to be something with the APs. But a user should have to do that.

Has anyone heard of these kind of problems. I have had so many clients having problems with the FAPs, I am att crossroad where I am seriously thinking about exchanging those and never look back. But that would be very expensive.

I spoke to some other IT guy and many of them say FAPs are ****. But I am really wondering. Is it that bad. What do you guys here on the forum think. Do you have setups with FAPs that are working great. How do you setup the FAPs.

For one thing, I noticed when I only run 5GHz on a SSID the handoff from AP to AP does not work. But if I turn on 2,4GHz it works. That seems weird. I also tried setting up different AP profiles for different APs in the same office so that I can choose band and stuff like that. As soon as I do that the users complain about lots of issues. So for now I am running everything very "auto" which I think is weird that I need to do with expensive APs like this.

Please do help out. Even if it is telling me, stay away from FAPs. But if you have a working setup with at least 3 or more APs, how does your AP profile look and things like that. 

Thanks, I really hope we can solve this, or I will have a lot of APs to exchange... that will be a big hit for my company, Something I dont think I deserve since I am just trusting my distributor and selling a brand I that thought did proper products.

PS. All my clients are Mac users if that helps in some way.

[Johan_Witters]

If your clients connect to an ap at the end of the building, it looks like your cells are overlapping way to much. Wifi cells should not overlap by more than 10%, radio provisioning can help if your wifi profile on the fgt has automatic power levels configured. If however the fgt has to power down the ap's to much it would indicate you have to much ap's and/or they are too close to each other. I can recommend performing a wifi survey to check on overlap.

Keep in mind that wifi problems in many cases are related to client issues: the client ultimately decides on which ap to connect, and how long it stays connected to that ap. You can "tweak" this a little on the fgt by configuring ap handoff, but if you have stubborn smartphones your in for a treat.

We have by now >2000 ap's deployed with our customers, all possible types and have little issues with these. Most issues we had were due to bad design (too few/many ap's) until we made wifi surveys mandatory, a few times a bug gave us some headaches. But mostly the issues are related to smartphones not wanting to connect (iPhones not accepting @ or * in a psk, clients refusing to roam even if signal strength is -85dbm, etc)

[dudarra]

hey guys,

Yesterday we had the Campus meeting with ICT Team. They all complained about the disconnects and the bad performece after the Upgrade. We Upgraded the FW 300D (5.2.4 build 688) and the FAP to the new and v5.2-build0245! the performance is noticeably worser!

What is your advice? should i downgrade the FAP?

Guys need a solutions! quickly!

raffa

[wanglei_FTNT]

Hi Raffa,

It's difficult to give advice without digging into details.  it might be related to your specific config/radio environment/user traffic etc since we have  numerous customers using similar HW/SW combinations without issues. You can post some basic config related to wireless here if you don't mind. Otherwise, I  suggest you open a Fortinet support ticket so our folks can better assist you. 

Thanks

[dudarra]

cheers man,

here is my default Wlan FAP profile!

raffa

[Bromont_FTNT]

No channels selected? Do you have other APs/profiles?

[Chris_Carson]

Here are some thoughts.

FortiAP's have CPUs/Memory.  You can check this by going directly to the IP address http://<ipaddress>

  I have found that enabling the spectrum analyzer really eats CPU cycles and can have drastic effects.

Other thoughts

[ul]

disable spectrum analyzer (if you are going to use it as dedicate a unit)

Make sure FortiAP firmware is updated and supported by the controller.

disable client load balancing except in a high concentration area ie: auditoriums (Different AP profile)

Ripple effects and "loops" happen when each radio(s) autodetect channels and power tx settings then fight against each other. Increase Daarp optimization timer and increase to 28800[/ul]

config wireless-controller timers
set darrp-optimize 28800

[ul]

You want them on 5g... so lower tx power on 2.4 and blast 5g

Drop 802.11b support

Use 40 mhz width since this is the most common radio in use today... only use 80 mhz if you want speed and have lots of 802.11ac devices.

Create a dedicated AP profile for each radio and statically set the TX power and radio channel (RF channel separation is important and remember to take into consideration your channel width)

Call tech support and be patient.[/ul]

WiFI is an "art"... not an exact process. I've used hundreds of different wifi products and they all have their strengths/weaknesses.  WiFi only thrives in mobile environments and it will never be as stable as an ETHERNET CABLE! ;)

Best Regards,

Chris

[eyexmeetsxeye]

My settings are almost the exact same as Stephen's post above. 5.0.10-12, and build 86 on the AP. I've gone farther and done custom AP profiles for each and every AP on the network to control what channel and power it will broadcast on (based on a RF survey I can then assign accordingly for the best wireless coexistence), disabling radio resource provisioning. I have not played with the DARRP, but instead take the route of setting everything manually. If you have 1-3 AP's this may work, but I always go with wireless survey.

I'm in a situation a lot of the time where I have to use the mesh and utilize the backhaul as 5Ghz. Saying that, wireless coexistence is a high priority on my list. I stick with 20mhz channel width. Every wireless printer (even if hardwired), Dect6.0 phone, and who knows what else device is broadcasting on 2.4 or 5. Even when using the 5Ghz band for client side, I still stick with 20mhz, as the source feed is less than 50Mbps, so giving a wireless client a speed of 150-300Mbps is waste of airspace. The best way is to be efficient and use the medium to higher products with MIMO, unless you are in a small office spare area where you will never have more than 10 clients connected.

Watching your CPU and memory use is key. You have to remember that even though you have a max value table for most AP listing max clients as "50", rule of thumb is half what the manufacturer says. You have to factor that in if using mesh, as "root" radio will be doing double duty, processing its own clients, plus streaming from 1-3 other radios and their clients.

Do not try to do VOIP/SIP/HQ dedicated video conference over wireless unless it is a dedicated point to point link/AP to client connection. You will forever be troubleshooting why calls random cut in and out, or are "choppy"

[colorcode]

Hi Anyone still experiencing this issues?

[dudarra]

Yes, when you don't choose any channels, the FAP will select automatically a channel!

raffa

[bellaciccod]

Hi Guys,

This problem I had some month ago.

Infrastructure:

#1 cluster of 2 fortigate 60D

#2 FortiAP 24D

After upgrade e downgrade of the firmware both fgt and fortiap the problem is the same.  The support doesn't solve the problem...

When one day I set 100 MBps port of my switch (HP Gigabit), where is connected the fortiAP and the problem is solved it!!!

You try it!

---

Davide