Fast WIFI (95 Megabit), but slow internet (35 Megabit)

[mensa]

Hi,

I just installed my first UAP-AC-LR at home and have some questions, if that behaviour is normal.

My DSL internet connection speed is 80 Megabit/s download and 20 Megabit/s upload. Normally I reach 75 to 80 Megabit/s at speedtest.net. I have that DSL modem (Huawei HA 35-22/AM) from my provider and put my Asus RT-AC3200 Router in the DMZ to use it as router. My new UAP-AC-LR is connected to the Asus router. All Cat6 cables.

I configured for testing only a very basic configuration of my UAP. I created a own SSID for 2.4 GHz and an own for 5 GHz.

I have that (mysterious?) problem:
When I do a speedtest at speedtest.net on wired and 5 GHz wireless clients I get results around 75 - 80 Megabit/s.
But when I do a speedtest on 2.4 GHz wireless clients I get only around 35 Megabit/s results. Now one could think about crowded 2.4 GHz, interferences and so on. But my 2.4 GHz is working very fast. When I do a iperf3 speedtest from WIFI to LAN I get following results:

So my 2.4 GHz WIFI speed is at around 95 Megabit/s and therefore even faster than my internet connection, but anyway I get everytime only around 35 Megabit/s speedtest.net results. And when I try quickly before or after that a speedtest on a wired or 5 GHz wireless client I get nearly 80 Megabit/s.

Is that normal?
I also tried different channels and different channel width, but it does not help. And I think my WIFI is not the problem cause as you can see I get round 95 Megabit/s speed over my 2.4 GHz WIFI. How can I find out the bottle neck?
I also disabled all other clients and see on my router that nothing else is using my WAN connection during I running speedtests.

 

[pitboss]

2.4Ghz, read this https://community.arubanetworks.com/t5/Wireless-Access/real-speed-of-802-11n-on-2-4ghz/td-p/41928 or some other max speed 2.4Ghz with bonding or multiple streams.

 

[mensa]

Please read my post, I have enough 2.4 GHz throughput (95 Mbps)! Even more than my WAN speed (80 Mbps), but only get 30 Mbps from WAN -> 2.4 GHz WIFI.

 

[System Error Message]

the problem isnt what you think. Iperf is capable of saturating a link because it is totally different from speed test. I managed to get 90% usage of my 2 channel wifi AC adapter but not without significant packet losses. Try iperf and look at your connection stats for packet drops. When i use it however for file transfers i get half that and it has nothing to do about the link.

Wifi practical usage != wifi benchmarks.

The shared nature of wifi is what can cause the practical speeds to be low. if a packet drops this severely affects throughput if a retransmit is done. When a benchmark runs there isnt a chance to transmit a retransmit so the transmission continues. besides practical speeds for 2.4Ghz wifi is 30% of link.

You may also have interferences you dont know. A lot of wifi based devices use 2.4Ghz just not the same wifi protocol as your network. These things use only 1 channel vs the wider channels used by your wifi networks and so can cause interference. This isnt limited to things you commonly hear, even car keys, remotes and many other things now all use 2.4Ghz rather than in the past where they used infrared. Before bluetooth came around even phones could use infrared to communicate with PC. Wireless speakers and keyboards use 2.4Ghz as well.

 

[Razor512]

How many connections does iperf make by default?
Sometimes WiFi will do that strange thing where a single client may need to make more than one parallel connection before the connection is fully saturated.

 

[mensa]

@SystemErrorMessage: Thanks for that good explanation.

But when internet speed test is so different to iperf, then isn't there any other possibilty/program to make the same speed test as (for example) speedtest.net for my local WIFI <-> LAN to locate the problem?

In windows explorer I can copy files from LAN to 2.4 GHz WIFI at around 12 Megabyte/s = 96 Mbps. Is that file copy also so different to speedtest.net?

Very strange is, that the Unifi iPhone App can measure up to nearly 500 Mbps WIFI througput to my iPhone 7 (distance 1 meter, 5 GHz) but I still get only 30 Mbps at speedtest.net using my iPhone 7. I understand, that practical speed can be lower, than measured throughput, but that big difference is absolutely not normal.

Very interesting is also, that until 10 days ago I reached 80 Mbps at speedtest.net also over WIFI without any problems (2.4 GHz and 5 GHz). There was no configuration change and also no new devices (also no other radio devices). I live in the country, so it also can't be a neighbour.
When I do a speedtest through LAN at speedtest.net I get always around 70 - 80 Mbps.

To be sure, that it won't be interference I even took a long Cat6 cable to to my cellar into a bomb shelter and started the access point there. Before I shut down every wireless/radio device at home. Result: Same problem als othere.

I really don't understand it anymore

 

[pitboss]

I have with me 5 asus routers, courtesy of asus for some real life tests. Tests is still on going, but I can say that NONE of the routers can give me 96mbits on 2.4GHz on the LAN tests with iPerf3 and all WAN tests resulted in 30-40mbit only and I have a 500mbit internet up and down. All tests done at -40dBm signal strength.

Your iperf is tested as Client>WiFi>LAN>Server while for Internet it is Client<WiFi<WAN<MODEM<Internet . Maybe there is some issues between WAN and 2.4GHz band that is causing this.

Do a test with a public iperf servers and see how the result is.

 

[mensa]

I connected one PC to the WAN port of the router and made an iPerf3 test from outside (WAN) to my 2.4 GHz WIFI client and also had around 95 Megabit/s as result.
So there is also not problem between WAN/WIFI and I understand it everyday less, where the problem could be located.

 

[sfx2000]

How many connections does iperf make by default?
Sometimes WiFi will do that strange thing where a single client may need to make more than one parallel connection before the connection is fully saturated.

iperf/iperf3 is a single thread/connection by default - there are switches to increase the number as needed - check the man info on options...

 

[pitboss]

I connected one PC to the WAN port of the router and made an iPerf3 test from outside (WAN) to my 2.4 GHz WIFI client and also had around 95 Megabit/s as result.
So there is also not problem between WAN/WIFI and I understand it everyday less, where the problem could be located.

I've tested with iperf3 om Windows 10, OSX, android and iOS and all of them on 2.4Ghz can manage a maximum of 60mbit and speedtest.net correspond to iPerf3 result as well.
However on Asus AC5300, the results as follows:
iPerf3 shows a 88/88 but beta.speedtest,net results is 95/95.

What do you get from iPerf3 when you are on 5Ghz?

 

[mensa]

Around 450 Mbps.