Wi-Fi on iPhone 6s very slow

dirk · August 24, 2019, 6:02pm

Hi,

since I'm back from my vacation since Thursday evening I'm playing around with my newly setup openWrt LinkSys EA4500/E4200v2 router and its wireless settings.

I currently configured three wifis:

MY_WIFI -> a first private wifi for my personal devices (laptop, tablet, iphone...)
MY_WIFI_N -> a second private wifi for my personal devices (laptop, tablet,...)
MY_WIFI_IOT -> contains all my IOT devices
MY_GUEST -> if I want to provide access to the internet for guests

The first thing I remembered was, that MY_WIFI_N has a very low signal strength on my laptop, only some meters away from the router. That's why I deactivated it now; does it make sense to reactivate it again for any reason?

My main reason I'm creating this post is, that the wifi speed of MY_WIFI on my laptop reaches 60 MBit/s with speedtest from my laptop, but only 30 MBit/s from my iPhone 6s via speedtest.net app. Ok, that sounds like "luxury problems", but in real life, I try to open a website via safari browser and it takes quite long to open and hangs at about 10%. Additionally, I e.g. have an app, that loads my personal account data each time I use the app from the internet. This takes sooooooo incredible long. When I do the same (it's always the same data loaded, except I add something new) from our company's wifi, via 4G,... it is super fast. This should just be some json data loaded, no videos, photos,...

I would appreciate if you could help me and have a look at my wifi settings. I already made some improvements, but never the less, it only extended the performance with speedtest, but not the subjective speed feeling.


config wifi-device 'radio0'
	option type 'mac80211'
	option channel '11'
	option hwmode '11g'
	option path 'mbus@f1000000/mbus@f1000000:pcie@82000000/pci0000:00/0000:00:01.0/0000:01:00.0'
	option legacy_rates '1'
	option country 'DE'
	option noscan '1'
	option htmode 'HT40'

config wifi-device 'radio1'
	option type 'mac80211'
	option hwmode '11a'
	option path 'mbus@f1000000/mbus@f1000000:pcie@82000000/pci0000:00/0000:00:02.0/0000:02:00.0'
	option legacy_rates '1'
	option channel '149'
	option htmode 'HT40'
	option country 'DE'
	option noscan '1'

config wifi-iface
	option device 'radio0'
	option mode 'ap'
	option ssid 'MY_WIFI'
	option network 'lan'
	option encryption 'psk2'
	option key '**********************************************'

config wifi-iface
	option device 'radio1'
	option mode 'ap'
	option ssid 'MY_WIFI_N'
	option network 'lan'
	option encryption 'psk2'
	option key '************************************************************'
	option disabled '1'

config wifi-iface
	option device 'radio0'
	option mode 'ap'
	option ssid 'MY_WIFI_IOT'
	option network 'lan'
	option encryption 'psk2'
	option key '******************************************************************************************'

Thanks and kind regards,

Dirk

mike · August 24, 2019, 6:33pm

Your config is fine, this is a known bug between these devices and Apple unfortunately, I used to have an ea3500 which is essentially the same as the ea4500 and I had the same problem with sites opening very slow or not all on my iPhone. It's noted on the device page and there's a bug tracker for it, but at this point it doesn't look like any further development will take place.

jeff · August 24, 2019, 8:33pm

Thanks for posting your config. I need to look into issues with an iPhone as well on different hardware.

A couple general suggestions:

Disable legacy rates on 5 GHz and, unless you’ve got some “ancient” devices, on 2.4 GHz as well.

With the same caveat, require “n” on 2.4 GHz and “ac” on 5 GHz. Check the specs for the iPhone as the 5s doesn’t support 802.11ac.

Set your security to psk2+ccmp

noscan may be preventing 802.11n or 802.11ac operation as scanning is required for wide channels as well as DFS channels in most jurisdictions.

mike · August 24, 2019, 10:59pm

I just assumed it would be the bug and skimmed the config, sorry about that, an old note I have about my ea3500 mentions a couple of possible fixes - disabling an ack setting - dissassoc_low_ack '0' , whether or not that actually worked I don't know unfortunately. Disabling group rekey is also mentioned in that note - wpa_group_rekey '0' , but the note says that has it's own security problems, so might need a use at your own risk warning for that one (both settings applied in wifi iface).

fuller · August 25, 2019, 7:29am

how does the default
20MHz on 2.4GHz radio and legacy rates not disabled perform?

you probably could live without two "private wifi" and once you start distrust wifi at all, with just the iot and a guest network (option isolate is your friend).

dirk · August 25, 2019, 4:59pm

Hello,

thanks for your responses.

@mike:
Thanks. What a pitty. But ok, I'm thinking about a new router that supports 802.11ac so I can do streaming over wifi...
I also added the "option disassoc_low_ack '0'" config to both, 5 and 2.4 GHz
-> this didn't work for me and speedtest got even slower.

@jeff:

I set "option legacy_rates '0'" for 5 and 2.4 GHz mode
I set "option require_mode 'ac'" for 5 and 'n' for 2.4 GHz -> the 'ac' option is not available at all in LUCI
I changed security to "psk2+ccmp" even if this option is not available in LUCI
the noscan thing I don't understand, what to do / configure for.
-> I removed the config changes again, after they slowed my wifi down (on the laptop and the smartphone)

@fuller:
I tried this before you posted you question, but it was even worse. On speedtest.net on the one hand and on the smart phone on the other hand.

Is there a possibility to find out which one is the currently most recommended 802.11ac router for OpenWrt? As I wrote above, I'm thinking about replacing it, so I can do some streaming over wifi (I don't have LAN and PowerLine is too slow, too).

Thanks and kind regards,
Dirk

shm0 · August 25, 2019, 5:28pm

If I remember correctly,
Apple recommends 20MHz channel width for 2.4GHz band and
40 MHz channel width for the 5Ghz band.
DTIM value of 3 or greater. (with a beacon interval of 100)
But many APs have problems with apple devices

dirk · August 25, 2019, 6:30pm

Hello shm0,

thanks for your response. I changed both, the htmode to hw20 and the dtim to 255. The hw20 htmode option had also influenced my laptop internet speed. Then I reset it to hw40 again and left dtim by 255. I got the feeling, safari is really loading pages much faster. On my laptop inet speed it only had a little influence (even if I understood openwrt documentation that it shouldn't).

I keep an eye on it.

Thanks and kind regards,

Dirk

shm0 · August 25, 2019, 7:27pm

255 maybe is a bit too much.

dirk · August 26, 2019, 4:39am

Ok, I'll set it to a lower value. Thanks.
I remembered that I sometimes my wifi was disconnected, from my laptop, after I changed it. Perhaps that also was the reason.