Community discussions

MikroTik App
 
fleg
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 76
Joined: Mon Nov 06, 2017 12:31 pm

Incredible speed of AC2 wifi

Sun Feb 20, 2022 1:36 pm

I`v made a lot fo tests of MT`s indoor wifi in the past and my result was not good for MT.
I`ve used AC2, AC3, RB4011 in my test ant try AC2-AC2, AC3-AC2....and all APs vs clients and made tens of tests.
Max speed in 2.4GHz was abou 100-120Mb/ and ~200Mb/s in 5GHz.

New story.
I was replaced some TP-Link over AC2 in the customer`s a few days ago.
Customer has optical connection 350/70 and I could see incredible results of speedtests.
200Mb/s in 2.4Ghz and ~330Mb/s in 5Ghz (I`v never seen it before).
I tested in via my nb with Realtek RTL8822BE and my phone (Huawei P20 pro).
Unfortunately I can`t remeber what ROS was in AC2 but it was new piece and I bought about 10pcs a few weeks ag so I think there is some 6.4x ROS (I can unbox another AC2 and cehck it later)
I have no idea why I never coud measuring such results before and it must be miracle.
Any logical explanation?
 
User avatar
bpwl
Forum Guru
Forum Guru
Posts: 2984
Joined: Mon Apr 08, 2019 1:16 am

Re: Incredible speed of AC2 wifi

Sun Feb 20, 2022 3:27 pm

Theoretical interface rates are well known: https://mcsindex.com/

2.4GHz will only use HT part of that table (802.11n) , so max interface rate for dual stream is MCS15 , for 40MHz wide channel is 300Mbps.
5GHz 802.11ac uses VHT table. Typical 866Mbps in 2-Stream, 80 MHz wide channel. (2x MCS09)

To see what interface rate you get, check the "Registration Table" and see things like "866Mbps-80MHz/2S/SGI" as best value. But some devices are even 3S up to 1300Mbps.

The "Data rate" is much lower than the interface rate for high speed connections, as the mandatory 802.11 overhead comes more into play. Package aggregation is then an important factor.
One can calculate what the net-data-rate can be, if no other device is interfering: viewtopic.php?t=165698#p912622
 
fleg
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 76
Joined: Mon Nov 06, 2017 12:31 pm

Re: Incredible speed of AC2 wifi

Sun Feb 20, 2022 5:35 pm

Theoretical interface rates are well known: https://mcsindex.com/

2.4GHz will only use HT part of that table (802.11n) , so max interface rate for dual stream is MCS15 , for 40MHz wide channel is 300Mbps.
5GHz 802.11ac uses VHT table. Typical 866Mbps in 2-Stream, 80 MHz wide channel. (2x MCS09)

To see what interface rate you get, check the "Registration Table" and see things like "866Mbps-80MHz/2S/SGI" as best value. But some devices are even 3S up to 1300Mbps.

The "Data rate" is much lower than the interface rate for high speed connections, as the mandatory 802.11 overhead comes more into play. Package aggregation is then an important factor.
One can calculate what the net-data-rate can be, if no other device is interfering: viewtopic.php?t=165698#p912622
Theoretical values is not important in this case.
I`ve NEVER get these speeds before and I tried to find solution especially in 5GHz...e.g. in this thread...viewtopic.php?t=174294.
I thought there is only one solution ROS7 with new wifi protocol implementation but now I`m little confused.
Last edited by fleg on Sun Feb 20, 2022 7:08 pm, edited 1 time in total.
 
404Network
Member Candidate
Member Candidate
Posts: 285
Joined: Wed Feb 16, 2022 2:04 pm

Re: Incredible speed of AC2 wifi

Sun Feb 20, 2022 6:13 pm

I wont speculate on 5ghz but the capac, capacxl and hapac3 have max 2.4 TWO WAY tx of 300Mbps.
Even without losses the best one way tx speed one can do is 150Mbps.
With losses I use the 1/3 rule of one should get around 100Mpbs.

Therefore I dont think your testing is valid if it yields, 200Mbps in up or down speeds . You have defied the laws of physics unless that is the combined up and down speed in which case it would make sense.
 
User avatar
bpwl
Forum Guru
Forum Guru
Posts: 2984
Joined: Mon Apr 08, 2019 1:16 am

Re: Incredible speed of AC2 wifi

Sun Feb 20, 2022 6:48 pm

Therefore I dont think your testing is valid if it yields, 200Mbps in up or down speeds . You have defied the laws of physics unless that is the combined up and down speed in which case it would make sense.
Combined up and down will not be higher. 802.11 is half-duplex, only one can send at a time and consumes part of the available air-time, which is unique for all members in that channel.
With combined up-down one will see less than halve the throughput in one direction. (less than halve, because there is some loss of time)
I`ve NEVER get these speeds before and I tried to find solution especially in 5GHz...e.g. in this thread...viewtopic.php?t=174294.
Theoretical speeds are almost reachable in a clean and correct environment. My test numbers and screenshots are in the mentioned link. I also explained WHY the MT with the classic drivers only gets 370Mbps with an 866Mbps interface rate. The wifiwave2 package in ROS7 will get 580Mbps. It is clear with the recent posts in the Forum that ROS7 has a serious performance problem with the classic drivers. !

And for the 300Mbps test: 205Mbps is the max for a 2.4GHz , 300Mbps interface rate, 40MHz wide with the Mikrotik buffers. Other brands with the larger allowed buffers can get up to 245Mbps. (That is the total capacity for the channel, it is very rare to have a clean free 40 MHz channel in 2.4 GHz). TCP traffic will be slower because the mandatory ACK's come in the opposite direction and also because "TCP congestion avoidance" often kicks in.

How can one ask for a "logical explanation" if theory is not accepted?
 
fleg
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 76
Joined: Mon Nov 06, 2017 12:31 pm

Re: Incredible speed of AC2 wifi

Sun Feb 20, 2022 7:16 pm


How can one ask for a "logical explanation" if theory is not accepted?
One more...I`ve made a tens of tests in the past and I NEVER got these results.
I had the same hw, probably similar ROS (some 6.4.x), the same clients.
I tried tested on the desk with ideal conditions and every time I`v got only average results (120Mb in 2.4, 200 in 5GHz).
How is it possible I have a incredible results in one day so different as previous?
 
User avatar
bpwl
Forum Guru
Forum Guru
Posts: 2984
Joined: Mon Apr 08, 2019 1:16 am

Re: Incredible speed of AC2 wifi

Sun Feb 20, 2022 7:39 pm

Different location is an easy reason.

- check the "Registration table" for link quality and speed. Moving a device half a meter can give a complete different outcome. Reflections on wall's, ceiling and furniture changes this.
- MT does not indicate how busy a channel is. You can only measure it indirectly with MT, when clients cannot connect. Use "Freq Usage" and "Snooper" to so what else is there.

Wifi RF signal is invisible, is not stopped by wall's , and goes over 250 meter, even when the signal is totally unusable for communication, it makes other just wait.

To find out "what" is causing the slower than expected rate, checking the "Registration table" and the channel activity is just a minimum.
Interpretation is not easy. Say there is one weak far away device talking to another AP continously at 100Mbps , well that will be your max speed as well. (It's all about air-time, the slower gets more of it, consuming an overly large part of it, the faster device has to wait until the slow one has done.)
 
holvoetn
Forum Guru
Forum Guru
Posts: 5404
Joined: Tue Apr 13, 2021 2:14 am
Location: Belgium

Re: Incredible speed of AC2 wifi

Fri Feb 25, 2022 10:47 am

After some testing/experimenting ... it can be done, sort of ?

HapAc2, running ros7.2rc4, connected to 1Gb switch.
Regulatory domain / Country etsi2 / any installation, Frequency auto = channel 149 selected (SRD channel)
Channel width set to 20/40/80 XXXX (since I'm alone there as far as Wifi scanner on PC tells me :lol: )
Power manually adjusted to all rates fixed / 10 (AP is 40cm away from me, might still be too much)

Iperf3 server on linux box, connected to the same switch as HapAC2.
From laptop wired on the same switch I get 950-ish Mb throughput, proving the switch is more then capable enough.
I also tested connecting the laptop to HapAC2 eth port, same result. Switch and HapAC2 are able to handle the traffic just fine.

Using Samsung S20 connected to 5Ghz, HE.NET tool on device, 10 seconds and 200Mb package, I get speeds consistently above 390Mbps (I've seen 511 on 1 occasion, mostly around 400).

I do not get those speeds using TPLink Deco P7 (no config possible at all, purely auto !), nor Sitecom WLX-7000 (VERY limited config possible, only first 4 channels of 5GHz band available which are overcrowded already where I am, no option to use ac only).
Using the normal lower 5GHz channels on Hap AC2, I can get to 227/230 max. Not more. More or less the same as on those other APs.
But then again, my outgoing connection is 200/20 (reality 193/19.7, tested every hour), so why should I care about "only" getting 200-something over Wifi at home ??

Anyhow, the major take-away point, I think (which bpwl always says): the channels you want to use need to be as clear as possible from whatever interference.
 
ivicask
Member
Member
Posts: 422
Joined: Tue Jul 07, 2015 2:40 pm
Location: Croatia, Zagreb

Re: Incredible speed of AC2 wifi

Fri Feb 25, 2022 10:51 am

IM getting this on practically any mikrotik AC device, HAP,CAP,WAP, and with multiple clients like phones or laptops etc..

This example from capsman in local forward and WAP AC, S21 Ultra, 3m away, mostly clear environment, less than 10 clients doing no traffic same time as me during test.
You do not have the required permissions to view the files attached to this post.
 
holvoetn
Forum Guru
Forum Guru
Posts: 5404
Joined: Tue Apr 13, 2021 2:14 am
Location: Belgium

Re: Incredible speed of AC2 wifi

Fri Feb 25, 2022 11:29 am

Here is one of the results I took a screenshot from, a fair bit above 400Mb.
Screenshot.jpg
You do not have the required permissions to view the files attached to this post.

Who is online

Users browsing this forum: No registered users and 21 guests