Slow tx rate with 2.4 Ghz on Cap ac

RouterOS Wireless Networking
1

Hello

I have 4 x Cap ac + 1 x hex poe setup with capsman in our house
There is no problems with 5 Ghz band: when client is in the same place with Cap AC it have tx rate between 300+ and 700+ Mbps
When I move client ( Macbook in my case) to another room under 50 cm brick wall, 5 Ghz have a slow signal and client reconnects to 2,4 Ghz with tx rate about 50-65 Mbps in 802.11n

Moving macbook to same room (and to same desk with cap ac too), cant help to increase tx rate
I have same issue with iOs and Android phones and with another macbook
I try to disable all of cap and testing connection with one cap ac in 2,4 Ghz – have the same tx rate…

To be fair, I note that once I saw a session at 144 Mbps but after changing the settings I could not return to this mode

Can you help me, please
How to increase the tx rate in 2.4 Ghz closer to 300 as I can see in specification?


Firmware is 6.47.7

config:

/caps-man channel
add band=2ghz-g/n control-channel-width=20mhz extension-channel=XX frequency=2437 name=channel24-6 tx-power=15
add band=5ghz-onlyac extension-channel=XXXX name=channel5-1 tx-power=17

/interface bridge
add admin-mac=48:8F:5A:DE:CC:24 auto-mac=no comment=defconf name=bridge

/caps-man datapath
add bridge=bridge client-to-client-forwarding=no local-forwarding=no name=datapath-main

/caps-man security
add authentication-types=wpa2-psk encryption=aes-ccm name=security-main passphrase=*********

/caps-man configuration
add channel=channel24-1 country=no_country_set datapath=datapath-main distance=indoors hw-protection-mode=cts-to-self max-sta-count=20 mode=ap name=cfg-main rx-chains=0,1,2,3 security=security-main ssid=Gloria tx-chains=0,1,2,3
add channel=channel5-1 country=no_country_set datapath=datapath-main distance=indoors mode=ap name=cfg-main5ghz rx-chains=0,1,2,3 security=security-main ssid=Gloria tx-chains=0,1,2,3
/caps-man interface
add channel=channel5-1 configuration=cfg-main5ghz datapath=datapath-main disabled=no l2mtu=1600 mac-address=48:8F:5A:72:D9:93 master-interface=none name=cap1-5 radio-mac=48:8F:5A:72:D9:93 radio-name=cap1 security=security-main
add channel=channel24-1 configuration=cfg-main configuration.distance=indoors configuration.hw-protection-mode=none configuration.rx-chains=“” configuration.tx-chains=“” datapath=datapath-main disabled=no l2mtu=1600 mac-address=48:8F:5A:72:D9:92 master-interface=none name=cap1-24 radio-mac=48:8F:5A:72:D9:92 radio-name=cap1 security=security-main
add channel=channel5-1 channel.tx-power=17 configuration=cfg-main5ghz datapath=datapath-main disabled=no l2mtu=1600 mac-address=48:8F:5A:72:C6:BD master-interface=none name=cap2-5 radio-mac=48:8F:5A:72:C6:BD radio-name=cap2 security=security-main
add channel=channel24-1 configuration=cfg-main configuration.rx-chains=“” configuration.tx-chains=“” datapath=datapath-main disabled=no l2mtu=1600 mac-address=48:8F:5A:72:C6:BC master-interface=none name=cap2-24 radio-mac=48:8F:5A:72:C6:BC radio-name=cap2 security=security-main
add channel=channel5-1 configuration=cfg-main5ghz datapath=datapath-main disabled=no l2mtu=1600 mac-address=C4:AD:34:AF:41:7D master-interface=none name=cap3-5 radio-mac=C4:AD:34:AF:41:7D radio-name=cap3 security=security-main
add channel=channel24-1 configuration=cfg-main configuration.rx-chains=“” configuration.tx-chains=“” datapath=datapath-main disabled=no l2mtu=1600 mac-address=C4:AD:34:AF:41:7C master-interface=none name=cap3-24 radio-mac=C4:AD:34:AF:41:7C radio-name=cap3 security=security-main
add channel=channel5-1 configuration=cfg-main5ghz datapath=datapath-main disabled=no l2mtu=1600 mac-address=C4:AD:34:9E:D2:B6 master-interface=none name=cap4-5 radio-mac=C4:AD:34:9E:D2:B6 radio-name=cap4 security=security-main
add channel=channel24-1 configuration=cfg-main datapath=datapath-main disabled=no l2mtu=1600 mac-address=C4:AD:34:9E:D2:B5 master-interface=none name=cap4-24 radio-mac=C4:AD:34:9E:D2:B5 radio-name=cap4 security=security-main

2

I have a nice result

  1. get another cap ac (cap4 in my config)
  2. reset all settings (including default conf)
  3. setting up like this:

nov/12/2020 23:02:37 by RouterOS 6.47.7

software id = 7PQP-XZRY

model = RBcAPGi-5acD2nD

serial number = BECD0B079DBF

/interface bridge
add name=bridge
/interface wireless

managed by CAPsMAN

channel: 2437/20-Ce/gn(13dBm), SSID: Gloria, local forwarding

set [ find default-name=wlan1 ] disabled=no ssid=MikroTik

managed by CAPsMAN

channel: 5180/20-Ceee/ac/P(15dBm), SSID: Gloria, local forwarding

set [ find default-name=wlan2 ] disabled=no ssid=MikroTik
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip hotspot profile
set [ find default=yes ] html-directory=flash/hotspot
/interface bridge port
add bridge=bridge interface=wlan1
add bridge=bridge interface=wlan2
add bridge=bridge interface=ether1
add bridge=bridge interface=ether2
/interface wireless cap

set bridge=bridge discovery-interfaces=bridge enabled=yes interfaces=wlan1,wlan2
/ip dhcp-client
add disabled=no interface=bridge
/system clock
set time-zone-name=Asia/Yekaterinburg
/system identity
set name=mt-cap4

  1. after cap4 started I have 144 Mbps on 2,5 Ghz
    its more than 65 was before reset
    It is a little success but rate is stil so far from 300 Mbps

  2. get cap2 and making 1-4 steps
    after cap2 started I have the same 65 Mbps...

here is config:

nov/12/2020 23:08:03 by RouterOS 6.47.7

software id = AI8E-PA6R

model = RBcAPGi-5acD2nD

serial number = BECD0C25F73C

/interface bridge
add name=bridge
/interface wireless

managed by CAPsMAN

channel: 2437/20-Ce/gn(13dBm), SSID: Gloria, local forwarding

set [ find default-name=wlan1 ] disabled=no ssid=MikroTik

managed by CAPsMAN

channel: 5180/20-Ceee/ac/P(14dBm), SSID: Gloria, local forwarding

set [ find default-name=wlan2 ] disabled=no ssid=MikroTik
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip hotspot profile
set [ find default=yes ] html-directory=flash/hotspot
/interface bridge port
add bridge=bridge interface=wlan1
add bridge=bridge interface=wlan2
add bridge=bridge interface=ether1
add bridge=bridge interface=ether2
/interface wireless cap

set bridge=bridge discovery-interfaces=bridge enabled=yes interfaces=wlan1,wlan2
/ip dhcp-client
add disabled=no interface=bridge
/system clock
set time-zone-name=Asia/Yekaterinburg
/system identity
set name=mt-cap2

Any ideas how to increase tx rate for my cap ac s?

3

How to increase the tx rate in 2.4 Ghz closer to 300 as I can see in specification?

The 300 Mbps is the interface (!) data rate when using 40 MHz wide channel and having a 2x2 spatial streams.(http://forum.mikrotik.com/t/cap-ac-2-4ghz-spatial-streams/135868/1)
2x2 depends also on the client device and the quality of the connection. With many reflections you can see it drop to 1s in the “Registrations”.
40 MHz is using 66% of all available bandwidth in the 2.4 GHz band. There are only 3 interference free channels if 20 MHz is used. You use channel 6 (2437) but with XX you do not know in what direction the second 20 MHz should be found, 1 or 11.

User/payload data rate will be 1/2 of the interface rate and lower !!
It is very rare to have 40 MHz as free channel in 2.4 GHz band. Every device can also send the “40 MHz- intolerant” bit, to forbid the use of a 40 MHz channel in the 2.4 band.

144Mbps interface rate, and 50-70Mbps data rate is very normal for 2.4GHz, 20 MHz channel and 2x2 spatial streams. (http://mcsindex.com/)

4

In other words 300Mbps is the additive two way Crap advertising number you will see on the box.

So lets start with reality! For one way transmission Divide by TWO (2).
Second one has normal propagation losses, compounded by walls and their materials and plain ole distance.
Thirdly there may be interfering electronic devices, wiring, lights etc.
Fourthly there may be other Access Points crowing the airspace.
and probably many others…

The rule of thumb I use is the 1/3 rule for a starting point of expected throughput with Line of Sight.
Thus 300/3, please look at 100 Mbps as what you might reasonably expect to get in a one way scenario at home.
Once you go through walls that will diminish but not as badly for 2gig vice 5gig (still useable) past one wall and sometimes two but things go downhill rapidly.

5

Thanks for your answer!

I have not illusions about it and talk about interface rate above, thank you!
In case of 65 Mbps TX rate on Macbook the data rate test shows up to 30 (in better cases up to 35) Mbps download and a bit more for upload

It’s a good news!
But how to explain the fact that other cap ac s do not go to 144 Mbps?
I have done steps 1-4 for all of cap s and only one shows 144 rate. Same environment, same macbook


It’s may looks so strange. Macbook as a client have 2x2 and successfully makes it with cap4 on 144 Mbps. But does not with another 3 caps
I would be very happy to get 144 Mbps interface rate on the remaining points but with the same configuration it doesnt works :confused:
In which direction you may recommend to look?

2,4 GHz in my case is very clean. I’m in a private house, neighbors are far from me. My wifi scanner shows 1-2 another routers sometimes with signal lower -88 dBm
have attached some screens
Screenshot 2020-11-13 at 00.48.20 AM.png
Screenshot 2020-11-13 at 00.46.27 AM.png

6

Well lets apply your new knowledge to the capac.
Advertised crap number - 867
Realistically 867/3 = 289 in LOS scenarios is what you should reasonably get.
Through one wall this will drop significantly but may still be useable, two walls not (and where 2.4 penetrates further).

7

it’s a very clear, of course!
but there is 3 points:

  1. one of 4 caps gets 144 Mbps, another does not
    in the same environment, all other things being equal

  2. with 5 GHz I have TX rates 780 an 866 (as “on the box”)

  3. I agree that for most tasks, 20-30 mbps is enough
    But not in a case of posting video to hosting or to social media services.
    And not in a case of sharing video between two phones inside one room

Why 2,4 Ghz in room can ask you
Its very simple:

To provide 5 GHz coverage throughout the house, 8-10 points are required. It’s a little expensive.
Now I expect to close the main zones at 5 GHz. Points will be set there. In adjacent rooms, I rely on 2.4 GHz through brick walls. And here with cap ac, sorry, even 20 mbps will not work. But the old mi router pro quite broke through 2 brick walls, half a meter each and gave out stable 80-100 Mbps on the same client devices. But he is, of course, a very scary microwave

1 and 2 points seem to hint that the issue is not closed and more can be squeezed out of 2.4 GHz.
And here I am :slight_smile:
And thank you very much for your help!
866.png
780.png

8

I would be glad if 5GHz went through a load-bearing brick wall, but this is not entirely true. Yes, in some places it passes, it turns out the tx rate on a macbook is about 180-230 (if I turn off 2.4 and it does not work everywhere).
The problem is that 2.4 cannot be turned off, there are devices without 5 GHz.
And if both ranges work, then client falling behind the wall often switches to 2.4 where the signal weakens less

9

You can play with settings on the capacs to disconnect from signals too weak.

10

In case when we need set priority to low signal 5 GHz connection? :slight_smile:
And we goes so far, sorry

The main question is how to configure capsman channel (or individual settings for each of cap ac) in 2.4 GHz that all of 4 caps gets 144 Mbps rate in the same environment (same room, patch cord, poe injector, macbook pro as a client).
Why only 1 of 4 can provide faster connection in equal conditions?

I don’t want to think that this is a marriage or a poor-quality transmitter, but it looks very much like that

11

You’re running 4 APs on 2.4GHz, all set to same frequency? That creates some interference …

If you insist on using 20+20MHz channels, you should be setting half of APs to channels 1+5 (Ce with frequency 2412) and other half to channels 9+13 (Ce with frequency 2452). Set same frequency on pairs of APs with least signal overlap to minimize interference.

12

Some more hints as some cAP ac’s seem to underperform (they do not go up to 144 Mbps interface rate)

It’s always guessing if the problem is not at hand, and that guessing can be quite off-topic. But still let me try.

-One of the tricks is to set the TX power of the 2.4 GHz band 7 dBm lower. (Reason is that the 5 MHz antenna is half the size of a 2.4 GHz antenna, and captures 1/4 of the sphere surface compared to the 2.4 GHz antenna) Now they receive equal power at the client, and the band selection algorithm works better.

  • One of the main causes of a bad signal is a too strong signal, or placement in the corner or near metal surfaces. The AP is always much stronger (20dBm) on default setting than the client (15 to 10 dBm). That strong signal can reverberate in a room and destroy its own quality by interfering reflections. Sometimes moving the AP 10cm can change the pattern.
  • You have 5 competing AP’s in 2.4MHz, as seen from a client device. An AP is more sensitive to receive other AP’s, clients, and RF transmitting devices. AP’s and clients on the same or nearby channel with make your AP wait if their signal is above -95 dBm (with noise level at -101dBm, as for the Microtik). Your client device does not even see those signals ! Use “Freq usage” and “Snooper” in Mkt to test.
  • Your best indication is the “Registration” information in the cAP ac wireless table. Read the TX and RX rate and the RX/TX CCQ. (speed-bandwidth/streams/short guard). What you want is 144MBps-20MHz/2S/SGI or even 300Mbps-40MHz/2S/SGI. A low CCQ will drop the MCS and the streams. CCQ is calculated from the ratio “TX/RX frames” over “TX/RX HW frames”. You will see the CCQ drop through a wall from 95% to something like 75%.
  • Airtime fairness is non-standard in wifi. (And Mkt has no airtime fairness setting). This means that a slow talker and a fast talker will get even chances to talk, but the slow one will talk much much longer every time. The throughput then for BOTH will be somewhat less than the throughput of the SLOW talker. Any talker with a signal above -95dBm to be counted here.

These are just some general things to be aware off. No idea if they play a role in your case or not.

13

I hope 1+5 and 9+13 do fit as 2 times 20+20 MHz. Most documents speak of 1-6 and 11 because US only goes up to 11, and they still consider the 22MHz wide B channels.

Adjacent channel interference is worse than co-channel interference. In Co-channel interference devices WAIT , in adjacent channel interference they destroy each others signal and then have to resend. (At what time they probably will destroy again). Only 802.11ac is capable of limiting two adjacent wide channels in width to avoid interference, if they are set up in opposite direction of expansion.
https://www.metageek.com/training/resources/why-channels-1-6-11.html

One can use one 40 MHz and one 20 MHz channel, and only have co-channel interference, if only channels 1-11 are available.

14

A chart illustrating channel usage in 2.4GHz WiFi outside North America (taken from Wikipedia article on WiFi channels).




20MHz channels, when used in 1-5-9-13 layout, technically speaking do overlap slightly … but they overlap in guard-band portion and it should not cause any noticeable interference.

In typical 2.4GHz setup (20+20MHz) one should look at middle chart (20MHz channels) … not at the lower chart (40MHz) because most devices don’t really support 40MHz channels, most (including Mikrotik) only support (multiple adjacent) 20MHz channels. I guess it’s similar for 5GHz where most devices support (multiple adjacent) 40MHz channels, not wider ones (80 or 160 MHz) - correct me if I’m wrong

15

OK. Nice! How to convince Europeans and Asians not to follow the US instructions, and also to always disable the “b” mode? If one sets or has a default of 1,6,9 we are in adjacent-channel interference again.

But yes, two 40MHz channels is great. Would not use it in the same room, as the signal is strong and the side-lobes get wider. Unless “Adaptive noise immunity” is also tackling this.

16

In case of OP with little (or no) external interference, and if he has to support legacy (802.11b) devices, he could choose channel layout Ce for 1+5 channel and eC for 9+13 channel. This way legacy operation would not interfere with adjacent APs, own extension channel would server as (quite wide) guard band. In case of any other channel layout (Ce-Ce, eC-eC or eC-Ce) legacy (slightly wider) channels would interfere with adjacent APs (even if both were operating in legacy mode).

17

I guess the only way is to post enough tutorials on youtube :wink:

18

Still waiting to see OP’s CCQ numbers. (Distortion, reflection and adjacent-channel-interference indicator)

19

Thanks for your help, but I still haven’t been able to squeeze anything more than 52-65 Mbps out of the 2.4 GHz cap ac.
Even if it only works, the MacBook and cap lies on the same desk and the environment is at the noise level.

I returned the whole set back to the store and returned the money.
It’s a pity for spending 10 days and nights on settings

As a positive note:
I learned a lot about the inner world of Mikrotik and RouterOS.
The world is huge and super customizable, it’s very cool!
I will follow up on the cap with good coverage and of course with Wifi-6 :slight_smile:

20

Get yourself a TPlink EAP245, and if you still get the same speeds its the macbook LOL. Depending upon its age you may have to play with selctions B+G, N+G, N only etc… cant remember the choices.