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rbuserdl
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WiFi limitations

Wed Jan 13, 2021 4:55 pm

Hello people!!!

I have seen in a Mikrotik document (that I cannot find now), that the ammount of devices connected to an AP could be more than 50 (If my memory is working fine, which probably isnt)
I have a RB951Ui-2HnD, which has about 16-18 devices connected throuhg Wireless, I had changed the frequency and the security profile setting in many ways with no luck
Download speed is up to 6 Mbps, sometimes less, even being with better than -40 dBm of "Tx/Rx Signal"
Signal noise is not so bad
With cable, download speed is about 100 Mbps
I dont have any queue limiting the bandwith
Here my questions:
1) Is it normal that with 18 devices connected concurrently the download speed does not be more than 6 Mbps?
2) Is there a way to calculate the bandwith that a wireless conected device will have?
3) Is it possible that this amount of devices causes disconnections or a lot of packet lost?

Thanks in advance.
Regards.
Damián
 
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bpwl
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Re: WiFi limitations

Wed Jan 13, 2021 5:47 pm

Some questions, many possible answers ... I don't know what detail you are looking for.

1. PHY rate.
You already looked at the TX/RX signal strength , but more information is in the TX rate, RX rate and CCQ (found under "registration" per connected device)
That TX rate is your current (dynamically changing) PHY rate. The bruto transmission is "TX rate" * "CCQ%"
I expect you to see for TX rate in the best cases 72.2Mbps-20MHz/1S/SGI (single stream client) or 144.4Mbps-20MHz/2S/SGI (dual stream device)
2 Netto data rate
This PHY is half-duplex, and has quite some overhead (25% till 60%). So you can get 40% till 75% of that PHY as throughput in one direction.
(Overhead is dependent on number of SSID's around, number of clients, PHY rate (higher PHY rates have more % overhead)
3. Airtime
The time to transmit is shared by all devices in the same channel or overlapping channels.
Every device around has the same rights to transmit. You already have 18 clients and one AP. But there is probably (much) more.
The chance to transmit is statistically divided over all devices (AP, clients, other devices), however a device with a low PHY rate will take more airtime when transmitting.
Silent clients are not using airtime. But a slow (weak signal) device will slow everyone down as it takes a very big share of the available airtime.

Is 6Mbps normal, with 18 clients? It certainly can be that low.
3 active, at 72,2Mbps PHY, 100%CCQ, 50% overhead ..... each has 12Mbps unidirectional, 6 Mbps bi-directional.
3 active, 2 at 144,4Mbps PHY, one at 6 Mbps PHY, 100% and 50%CCQ, 50% overhead .... the fast ones have an average rate of 3Mbps unidirectional , the slow one is at 1.5Mbps unidirectional.
18 active, at 144,4Mbps PHY, 100%CCQ, 50% overhead (ideal situation) ... each has 4 Mbps unidirectional.

To compare with the ethernet cable: PHY=100Mbps, CCQ=100%, overhead=5%, bidirectional. (and no slow PHY devices)
 
rbuserdl
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Re: WiFi limitations

Wed Jan 13, 2021 8:31 pm

Hello,

Thank you so much for all the explanatons.
I never paid attention to "Tx rate" and "Rx rate" because I dont know what means: "1S", "2S" and "SGI", also every item has a rate in Mbps and some items has a "20 MHz" after this, other items has only the rate in Mbps. This is no easy to understand for me.
I usually see that CCQ% depends on the signal strength, with good signal strength good CCQ and bad signal strengths goes to bad CCQ, so I dont know how can this value help me

I would like to upload a screenshot of the "Registration" tab to you give me some recommendation
Is this possible? Can you please tell me where can I upload the image?

Thanks a lot.
Regards,
Damián
 
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bpwl
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Re: WiFi limitations

Wed Jan 13, 2021 10:01 pm

Normally you can add attachments, and then "Place inline".
But some users did not get this possibility. Don't know why.
The same text information is in the terminal with: "/ interface wireless registration print stats"

1S is single spatial stream, is single transmission and receive chain used, is one path for the data. Also written as 1x1
2S is dual spatial stream, is two transmission and receive chains are used, there are 2 paths for the data (this doubles the throughput). Also written as 2x2
MT AP's sometimes have triple stream. But clients seldom have this. For 2x2 both AP and client device need to have 2 chains/antenna.

SGI : short guard interval (0.4µs)
---: long guard interval (0.8µs)

20MHz: is the 20 MHz bandwidth of the channel used

The CCQ is the % of useful transfers of data. The other are considered lost. (there was no ACK to acknowledge good reception)

Losing transmissions will lower the encoding (MCS), and will lower the PHY rate. Good transmissions will make the MCS increase.
For 802.11n (HT) MCS goes from 0 tot 7 for 1S. 2S then is expressed as HT MCS 8 till 15. (so HT MCS8 is 2xMCS0, HT MCS9 is 2xMCS1 ....)
MT does not show the MCS value, but the PHY rates are unique, so you can look it up.
(VHT is only for 802.11ac, HE is for 802.11ax)
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rbuserdl
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Re: WiFi limitations

Thu Jan 14, 2021 2:30 pm

Thanks again

There are less devices connected now
I dont have any option to attach files
I had tested some options in "/interface wireless registration-table print" but I didnt see the "stats" parameter.
Here are the results:
# jan/14/2021  9:12:43 by RouterOS 6.41.2
# software id = 1EKD-13UU
#
 0 interface=wlan1 mac-address=70:2E:D9:4A:36:CB ap=no wds=no bridge=no 
   rx-rate="65Mbps-20MHz/1S" tx-rate="65Mbps-20MHz/1S/SGI" 
   packets=22177,222642 bytes=1686047,39156561 frames=22177,223331 
   frame-bytes=1771593,37894397 hw-frames=61805,348594 
   hw-frame-bytes=6751107,49833917 tx-frames-timed-out=0 uptime=2d7h57m35s 
   last-activity=750ms signal-strength=-64dBm@HT20-7 signal-to-noise=37dB 
   signal-strength-ch0=-65dBm signal-strength-ch1=-70dBm 
   strength-at-rates=-62dBm@1Mbps 3s780ms,-63dBm@5.5Mbps 19m4s110ms,-
                  63dBm@HT20-0 1m47s90ms,-63dBm@HT20-1 5m3s220ms,-64dBm@HT20-2 
                  4s800ms,-64dBm@HT20-3 3m31s100ms,-63dBm@HT20-4 1m2s20ms,-
                  63dBm@HT20-5 3s140ms,-63dBm@HT20-6 2s350ms,-64dBm@HT20-7 
                  750ms 
   tx-ccq=75% p-throughput=55944 last-ip=192.168.41.76 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 1 interface=wlan1 mac-address=C8:C7:50:09:5C:36 ap=no wds=no bridge=no 
   rx-rate="1Mbps" tx-rate="13Mbps-20MHz/1S" packets=103053,21149 
   bytes=126002525,3296282 frames=103053,21199 frame-bytes=126211801,3174762 
   hw-frames=181360,29283 hw-frame-bytes=196775279,4229169 
   tx-frames-timed-out=0 uptime=3h33m52s last-activity=19s210ms 
   signal-strength=-90dBm@1Mbps signal-to-noise=11dB 
   signal-strength-ch0=-94dBm signal-strength-ch1=-92dBm 
   strength-at-rates=-90dBm@1Mbps 19s210ms,-89dBm@2Mbps 30m6s300ms,-
                  89dBm@5.5Mbps 30m6s100ms,-88dBm@6Mbps 13m58s330ms,-
                  80dBm@54Mbps 1h30m12s500ms,-85dBm@HT20-0 1h27m5s420ms,-
                  83dBm@HT20-1 1h27m9s750ms,-81dBm@HT20-2 1h28m10s830ms,-
                  82dBm@HT20-3 1h28m10s650ms,-79dBm@HT20-4 1h29m3s80ms 
   tx-ccq=32% p-throughput=2386 last-ip=192.168.41.100 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 2 interface=wlan1 mac-address=20:32:6C:FB:3F:AA ap=no wds=no bridge=no 
   rx-rate="72.2Mbps-20MHz/1S/SGI" tx-rate="57.7Mbps-20MHz/1S/SGI" 
   packets=245242,111702 bytes=342345654,15550256 frames=245242,111757 
   frame-bytes=342838078,14885953 hw-frames=409369,131631 
   hw-frame-bytes=585631627,20082416 tx-frames-timed-out=0 uptime=3h25m21s 
   last-activity=3s30ms signal-strength=-70dBm@1Mbps signal-to-noise=31dB 
   signal-strength-ch0=-72dBm signal-strength-ch1=-74dBm 
   strength-at-rates=-70dBm@1Mbps 3s30ms,-71dBm@11Mbps 3s490ms,-73dBm@HT20-0 
                  2m2s200ms,-87dBm@HT20-1 39m15s400ms,-81dBm@HT20-2 
                  11m29s890ms,-80dBm@HT20-3 11m28s710ms,-72dBm@HT20-4 
                  1m10s760ms,-72dBm@HT20-5 10m19s210ms,-72dBm@HT20-6 
                  10m18s550ms,-73dBm@HT20-7 3s430ms 
   tx-ccq=77% p-throughput=34263 last-ip=192.168.41.94 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 3 interface=wlan1 mac-address=BC:FF:EB:20:3E:61 ap=no wds=no bridge=no 
   rx-rate="26Mbps-20MHz/1S" tx-rate="58.5Mbps-20MHz/1S" packets=147816,98347 
   bytes=192022157,12110053 frames=147816,98378 
   frame-bytes=192321061,11523354 hw-frames=261027,132779 
   hw-frame-bytes=343496830,16556771 tx-frames-timed-out=0 uptime=2h11m21s 
   last-activity=40ms signal-strength=-76dBm@1Mbps signal-to-noise=25dB 
   signal-strength-ch0=-76dBm signal-strength-ch1=-84dBm 
   strength-at-rates=-76dBm@1Mbps 40ms,-76dBm@2Mbps 50s310ms,-73dBm@6Mbps 
                  1m15s280ms,-74dBm@9Mbps 19s710ms,-74dBm@12Mbps 16s710ms,-
                  72dBm@24Mbps 14m34s720ms,-74dBm@HT20-0 1s440ms,-75dBm@HT20-1 
                  1s610ms,-77dBm@HT20-2 1s360ms,-80dBm@HT20-3 40ms,-82dBm@HT20-
                  4 38s490ms,-80dBm@HT20-5 4m24s80ms,-76dBm@HT20-6 15m39s340ms 
   tx-ccq=66% p-throughput=35095 last-ip=192.168.41.70 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 4 interface=wlan1 mac-address=80:35:C1:41:82:8E ap=no wds=no bridge=no 
   rx-rate="2Mbps" tx-rate="13Mbps-20MHz/1S" packets=18708,14730 
   bytes=20403192,2121934 frames=18708,14765 frame-bytes=20441672,2037390 
   hw-frames=49398,20728 hw-frame-bytes=54170443,2845232 
   tx-frames-timed-out=0 uptime=1h28m15s last-activity=9s30ms 
   signal-strength=-90dBm@1Mbps signal-to-noise=11dB 
   signal-strength-ch0=-93dBm signal-strength-ch1=-95dBm 
   strength-at-rates=-90dBm@1Mbps 3s50ms,-87dBm@2Mbps 30s260ms,-85dBm@HT20-0 
                  19m53s560ms,-86dBm@HT20-1 58m54s410ms,-85dBm@HT20-2 
                  1h16m7s640ms,-82dBm@HT20-3 1h16m12s650ms,-81dBm@HT20-4 
                  1h18m20s530ms 
   tx-ccq=35% p-throughput=5081 last-ip=192.168.41.115 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 5 interface=wlan1 mac-address=24:18:1D:27:D1:A0 ap=no wds=no bridge=no 
   rx-rate="1Mbps" tx-rate="130Mbps-20MHz/2S/SGI" packets=4295,4759 
   bytes=1689792,2859755 frames=4295,4782 frame-bytes=1699314,2833686 
   hw-frames=5195,6953 hw-frame-bytes=2353956,3077038 tx-frames-timed-out=0 
   uptime=1h16m30s last-activity=4s30ms signal-strength=-56dBm@1Mbps 
   signal-to-noise=45dB signal-strength-ch0=-58dBm signal-strength-ch1=-63dBm 
   strength-at-rates=-56dBm@1Mbps 45s600ms,-78dBm@5.5Mbps 1h16m21s910ms,-
                  56dBm@6Mbps 1m12s170ms,-50dBm@12Mbps 1h9m53s60ms,-
                  53dBm@24Mbps 4s30ms,-55dBm@HT20-0 9m52s400ms,-53dBm@HT20-1 
                  9m51s670ms,-55dBm@HT20-2 45s680ms,-54dBm@HT20-3 59s970ms,-
                  54dBm@HT20-4 59s970ms,-52dBm@HT20-5 9m51s580ms,-55dBm@HT20-6 
                  9m48s880ms,-54dBm@HT20-7 54s330ms 
   tx-ccq=94% p-throughput=121375 last-ip=192.168.41.134 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

 6 interface=wlan1 mac-address=14:96:E5:4F:4F:69 ap=no wds=no bridge=no 
   rx-rate="1Mbps" tx-rate="58.5Mbps-20MHz/1S" packets=901,652 
   bytes=222552,206373 frames=901,675 frame-bytes=225286,204986 
   hw-frames=4397,1448 hw-frame-bytes=911342,250506 tx-frames-timed-out=0 
   uptime=1h4m6s last-activity=3s80ms signal-strength=-72dBm@1Mbps 
   signal-to-noise=29dB signal-strength-ch0=-72dBm signal-strength-ch1=-81dBm 
   strength-at-rates=-72dBm@1Mbps 23s650ms,-75dBm@2Mbps 15m28s80ms,-
                  72dBm@6Mbps 3s80ms,-71dBm@9Mbps 4m29s700ms,-71dBm@12Mbps 
                  4m29s300ms,-72dBm@HT20-0 4m30s510ms,-71dBm@HT20-1 
                  56m33s160ms,-74dBm@HT20-2 27s620ms,-72dBm@HT20-3 4m21s890ms 
   tx-ccq=83% p-throughput=50993 last-ip=192.168.41.81 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 7 interface=wlan1 mac-address=E4:5E:37:4F:99:35 ap=no wds=no bridge=no 
   rx-rate="72.2Mbps-20MHz/1S/SGI" tx-rate="52Mbps-20MHz/1S" 
   packets=46496,35158 bytes=29195832,17192470 frames=31924,35172 
   frame-bytes=29524185,16983044 hw-frames=64210,45645 
   hw-frame-bytes=58086603,18862862 tx-frames-timed-out=0 uptime=54m37s 
   last-activity=140ms signal-strength=-63dBm@6Mbps signal-to-noise=38dB 
   signal-strength-ch0=-64dBm signal-strength-ch1=-70dBm 
   strength-at-rates=-64dBm@1Mbps 1m2s60ms,-63dBm@2Mbps 10m59s230ms,-
                  62dBm@5.5Mbps 1m9s100ms,-63dBm@6Mbps 140ms,-64dBm@9Mbps 
                  7m58s80ms,-63dBm@12Mbps 1m18s740ms,-64dBm@18Mbps 46s150ms,-
                  65dBm@24Mbps 890ms,-64dBm@36Mbps 33s950ms,-64dBm@48Mbps 
                  1m10s620ms,-64dBm@54Mbps 25m17s780ms,-62dBm@HT20-0 
                  10m58s710ms,-64dBm@HT20-1 5m43s290ms,-63dBm@HT20-2 45s60ms,-
                  64dBm@HT20-3 20s730ms,-64dBm@HT20-4 18s910ms,-64dBm@HT20-5 
                  18s650ms,-65dBm@HT20-6 4s780ms,-65dBm@HT20-7 270ms 
   tx-ccq=66% p-throughput=37607 last-ip=192.168.41.110 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

 8 interface=wlan1 mac-address=A6:CD:6C:69:39:E3 ap=no wds=no bridge=no 
   rx-rate="104Mbps-20MHz/2S" tx-rate="130Mbps-20MHz/2S/SGI" 
   packets=16213,11664 bytes=19899426,2971270 frames=16213,11686 
   frame-bytes=19932256,2903664 hw-frames=25706,15104 
   hw-frame-bytes=29832080,3462875 tx-frames-timed-out=0 uptime=40m2s 
   last-activity=30ms signal-strength=-51dBm@1Mbps signal-to-noise=50dB 
   signal-strength-ch0=-55dBm signal-strength-ch1=-54dBm 
   strength-at-rates=-51dBm@1Mbps 40ms,-52dBm@HT20-3 1m20s880ms,-50dBm@HT20-4 
                  24s540ms,-49dBm@HT20-5 30ms,-50dBm@HT20-6 130ms,-51dBm@HT20-
                  7 2s950ms 
   tx-ccq=96% p-throughput=114881 last-ip=192.168.41.104 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

 9 interface=wlan1 mac-address=2C:33:7A:F5:62:93 ap=no wds=no bridge=no 
   rx-rate="144.4Mbps-20MHz/2S/SGI" tx-rate="144.4Mbps-20MHz/2S/SGI" 
   packets=59099,32771 bytes=59048561,11785807 frames=35711,32780 
   frame-bytes=59586799,11590170 hw-frames=51354,37498 
   hw-frame-bytes=97614026,13035730 tx-frames-timed-out=0 uptime=28m13s 
   last-activity=60ms signal-strength=-56dBm@1Mbps signal-to-noise=45dB 
   signal-strength-ch0=-58dBm signal-strength-ch1=-60dBm 
   strength-at-rates=-56dBm@1Mbps 60ms,-53dBm@HT20-0 13m13s750ms,-55dBm@HT20-1 
                  4m20s560ms,-56dBm@HT20-2 2s540ms,-55dBm@HT20-3 3s660ms,-
                  56dBm@HT20-4 2s350ms,-56dBm@HT20-5 4m16s200ms,-55dBm@HT20-6 
                  1m57s430ms,-55dBm@HT20-7 370ms 
   tx-ccq=85% p-throughput=115213 last-ip=192.168.41.106 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

10 interface=wlan1 mac-address=34:2E:B7:BB:58:87 ap=no wds=no bridge=no 
   rx-rate="78Mbps-20MHz/2S" tx-rate="144.4Mbps-20MHz/2S/SGI" 
   packets=50438,18379 bytes=59712346,6180218 frames=31145,18386 
   frame-bytes=60189985,6070717 hw-frames=48913,19612 
   hw-frame-bytes=101293253,7056465 tx-frames-timed-out=0 uptime=21m34s 
   last-activity=3s260ms signal-strength=-51dBm@1Mbps signal-to-noise=50dB 
   signal-strength-ch0=-59dBm signal-strength-ch1=-53dBm 
   strength-at-rates=-51dBm@1Mbps 3m4s660ms,-49dBm@6Mbps 3s350ms,-52dBm@HT20-2 
                  3m43s400ms,-54dBm@HT20-3 2m10s150ms,-51dBm@HT20-4 3s260ms,-
                  49dBm@HT20-5 15s970ms,-50dBm@HT20-6 16s530ms,-51dBm@HT20-7 
                  33s450ms 
   tx-ccq=58% p-throughput=48636 last-ip=192.168.41.73 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

11 interface=wlan1 mac-address=C0:8C:71:64:8B:8B ap=no wds=no bridge=no 
   rx-rate="39Mbps-20MHz/1S" tx-rate="52Mbps-20MHz/1S" packets=1586,1357 
   bytes=1088407,180582 frames=1586,1366 frame-bytes=1091809,173427 
   hw-frames=2517,2424 hw-frame-bytes=1586324,253427 tx-frames-timed-out=0 
   uptime=20m32s last-activity=8s720ms signal-strength=-67dBm@1Mbps 
   signal-to-noise=34dB signal-strength-ch0=-67dBm signal-strength-ch1=-73dBm 
   strength-at-rates=-67dBm@1Mbps 3s640ms,-67dBm@HT20-4 28s840ms,-68dBm@HT20-5 
                  54s700ms,-68dBm@HT20-6 55s800ms,-66dBm@HT20-7 1m43s140ms 
   tx-ccq=78% p-throughput=45367 last-ip=192.168.41.167 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

12 interface=wlan1 mac-address=90:63:3B:11:20:BA ap=no wds=no bridge=no 
   rx-rate="1Mbps" tx-rate="52Mbps-20MHz/1S" packets=1968,2226 
   bytes=441322,1481588 frames=1968,2234 frame-bytes=445452,1469122 
   hw-frames=5151,2491 hw-frame-bytes=1329136,1570808 tx-frames-timed-out=0 
   uptime=16m17s last-activity=7s570ms signal-strength=-84dBm@1Mbps 
   signal-to-noise=17dB signal-strength-ch0=-86dBm signal-strength-ch1=-90dBm 
   strength-at-rates=-84dBm@1Mbps 22s830ms,-85dBm@2Mbps 28s730ms,-79dBm@6Mbps 
                  7s570ms,-81dBm@9Mbps 10m28s210ms,-81dBm@12Mbps 10m25s940ms,-
                  85dBm@HT20-0 10m24s770ms,-83dBm@HT20-1 10m21s390ms,-
                  84dBm@HT20-2 10m22s280ms,-84dBm@HT20-3 10m25s400ms 
   tx-ccq=54% p-throughput=40136 last-ip=192.168.41.116 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

13 interface=wlan1 mac-address=94:B8:6D:DC:8E:B2 ap=no wds=no bridge=no 
   rx-rate="65Mbps-20MHz/1S/SGI" tx-rate="72.2Mbps-20MHz/1S/SGI" 
   packets=14175,10664 bytes=9200223,2177462 frames=10275,10684 
   frame-bytes=9299643,2115748 hw-frames=12796,11170 
   hw-frame-bytes=13494934,2581691 tx-frames-timed-out=0 uptime=10m20s 
   last-activity=130ms signal-strength=-65dBm@HT20-6 signal-to-noise=36dB 
   signal-strength-ch0=-68dBm signal-strength-ch1=-69dBm 
   strength-at-rates=-65dBm@1Mbps 8s350ms,-62dBm@2Mbps 14m4s840ms,-
                  62dBm@5.5Mbps 1m2s240ms,-64dBm@6Mbps 4s470ms,-63dBm@9Mbps 
                  7m16s580ms,-65dBm@12Mbps 1s590ms,-65dBm@18Mbps 34s230ms,-
                  64dBm@24Mbps 11s220ms,-64dBm@36Mbps 2s450ms,-65dBm@48Mbps 
                  2s450ms,-64dBm@54Mbps 6m17s550ms,-62dBm@HT20-0 8m11s870ms,-
                  64dBm@HT20-1 5m19s940ms,-64dBm@HT20-2 3m2s320ms,-62dBm@HT20-
                  3 40s520ms,-66dBm@HT20-4 6s10ms,-65dBm@HT20-5 4s260ms,-
                  65dBm@HT20-6 130ms,-65dBm@HT20-7 1s30ms 
   tx-ccq=92% p-throughput=54798 last-ip=192.168.41.123 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

14 interface=wlan1 mac-address=76:C1:E8:44:D3:B9 ap=no wds=no bridge=no 
   rx-rate="26Mbps-20MHz/1S" tx-rate="78Mbps-20MHz/2S" packets=1544,2512 
   bytes=232854,2924423 frames=842,2516 frame-bytes=246119,2909805 
   hw-frames=1474,3457 hw-frame-bytes=574837,3044116 tx-frames-timed-out=0 
   uptime=5m53s last-activity=3s710ms signal-strength=-61dBm@1Mbps 
   signal-to-noise=40dB signal-strength-ch0=-65dBm signal-strength-ch1=-64dBm 
   strength-at-rates=-61dBm@1Mbps 3s710ms,-59dBm@5.5Mbps 1m26s570ms,-
                  57dBm@6Mbps 3m28s220ms,-60dBm@24Mbps 3m5s160ms,-59dBm@HT20-0 
                  1m17s500ms,-59dBm@HT20-1 31s920ms,-59dBm@HT20-2 33s860ms,-
                  60dBm@HT20-3 4s220ms,-60dBm@HT20-4 34s230ms,-59dBm@HT20-5 
                  4s260ms,-60dBm@HT20-6 33s870ms,-59dBm@HT20-7 52s90ms 
   tx-ccq=72% p-throughput=64454 last-ip=192.168.41.153 
   802.1x-port-enabled=yes authentication-type=wpa-psk encryption=aes-ccm 
   group-encryption=aes-ccm management-protection=no wmm-enabled=yes 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 
Thanks
Regards
Damián
 
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bpwl
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Re: WiFi limitations

Thu Jan 14, 2021 5:36 pm

Let me filter this to the directly speed related values, and tell what I see on this output. (Other information like distance, type of device, etc will help you further to interpret those results.)
[e.g.: Smartphones have a weak TX power , and usually have only one chain (1S) ]

# jan/14/2021 9:12:43 by RouterOS 6.41.2
---> quite old RouterOS version. But stick with LT distribution, now it is at 6.46.8.
---> most are 1S devices. Some are 2S and use this good
---> if the number of frames is low (<5000), then the speed is not stable yet.
---> the performance of the 144Mbps/2S/SGI devices is KILLED by some very slow devices (like nr 1 and nr 4) . They take 50 times more airtime for the same transmission as the faster ones.
---> p-throughput is the data speed in Kbps you can achieve if that device is the only one active.
---> frames/hw frames transmitted ratio, learns how many of the transmissions succeeded. There are quite some retransmits. I do suspect interference with other devices or channels.
---> "tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" " is the setting of the interface. You have 802.11b enabled! (CCK 1-11) , allowing extremely slow devices (1 Mbps), and broadcasting beacons at 1 Mbps basic rate, creating loss of airtime. Remove the "b" mode, and go for "g/n" or "n-only", not "b/g/n". Unless you absolutely need "b" for a very old device. Nr 1 and nr 4 will not be able to connect, because they are too far away for the minimum 6 Mbps (used in g and n as basic rate), but at least they will not be able to slow everything down as much. The throughput for a slow and fast device together is not the average of their throughput ! Slow speed x , and fast speed y, then this will give speed "=(x*y) / (x+y)" each. (and Yes, this is slower than x !)
# jan/14/2021  9:12:43 by RouterOS 6.41.2

 0 interface=wlan1 mac-address=70:2E:D9:4A:36:CB 
   rx-rate="65Mbps-20MHz/1S" tx-rate="65Mbps-20MHz/1S/SGI" 
   frames=22177,223331 hw-frames=61805,348594 
   signal-strength=-64dBm@HT20-7 signal-to-noise=37dB 
   tx-ccq=75% p-throughput=55944 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 1 interface=wlan1 mac-address=C8:C7:50:09:5C:36 
   rx-rate="1Mbps" tx-rate="13Mbps-20MHz/1S" 
   frames=103053,21199 hw-frames=181360,29283 
   signal-strength=-90dBm@1Mbps signal-to-noise=11dB 
   tx-ccq=32% p-throughput=2386 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 2 interface=wlan1 mac-address=20:32:6C:FB:3F:AA 
   rx-rate="72.2Mbps-20MHz/1S/SGI" tx-rate="57.7Mbps-20MHz/1S/SGI" 
   frames=245242,111757 hw-frames=409369,131631 
   signal-strength=-70dBm@1Mbps signal-to-noise=31dB 
   tx-ccq=77% p-throughput=34263 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 3 interface=wlan1 mac-address=BC:FF:EB:20:3E:61 
   rx-rate="26Mbps-20MHz/1S" tx-rate="58.5Mbps-20MHz/1S" 
   frames=147816,98378 hw-frames=261027,132779 
   signal-strength=-76dBm@1Mbps signal-to-noise=25dB 
   tx-ccq=66% p-throughput=35095 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 4 interface=wlan1 mac-address=80:35:C1:41:82:8E 
   rx-rate="2Mbps" tx-rate="13Mbps-20MHz/1S" 
   frames=18708,14765 hw-frames=49398,20728 
   signal-strength=-90dBm@1Mbps signal-to-noise=11dB 
   tx-ccq=35% p-throughput=5081 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 5 interface=wlan1 mac-address=24:18:1D:27:D1:A0 
   rx-rate="1Mbps" tx-rate="130Mbps-20MHz/2S/SGI" 
   frames=4295,4782  hw-frames=5195,6953 
   signal-to-noise=45dB signal-strength-ch0=-58dBm 
   tx-ccq=94% p-throughput=121375 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

 6 interface=wlan1 mac-address=14:96:E5:4F:4F:69 
   rx-rate="1Mbps" tx-rate="58.5Mbps-20MHz/1S"
   frames=901,675  hw-frames=4397,1448 
   signal-strength=-72dBm@1Mbps  signal-to-noise=29dB 
   tx-ccq=83% p-throughput=50993 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

 7 interface=wlan1 mac-address=E4:5E:37:4F:99:35 
   rx-rate="72.2Mbps-20MHz/1S/SGI" tx-rate="52Mbps-20MHz/1S" 
   frames=31924,35172 hw-frames=64210,45645 
   signal-strength=-63dBm@6Mbps signal-to-noise=38dB 
   tx-ccq=66% p-throughput=37607 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

 8 interface=wlan1 mac-address=A6:CD:6C:69:39:E3 
   rx-rate="104Mbps-20MHz/2S" tx-rate="130Mbps-20MHz/2S/SGI" 
   frames=16213,11686 hw-frames=25706,15104 
   signal-strength=-51dBm@1Mbps signal-to-noise=50dB 
   tx-ccq=96% p-throughput=114881 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

 9 interface=wlan1 mac-address=2C:33:7A:F5:62:93 
   rx-rate="144.4Mbps-20MHz/2S/SGI" tx-rate="144.4Mbps-20MHz/2S/SGI" 
   frames=35711,32780 hw-frames=51354,37498 
   signal-strength=-56dBm@1Mbps signal-to-noise=45dB 
   tx-ccq=85% p-throughput=115213 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

10 interface=wlan1 mac-address=34:2E:B7:BB:58:87 
   rx-rate="78Mbps-20MHz/2S" tx-rate="144.4Mbps-20MHz/2S/SGI" 
   frames=31145,18386 hw-frames=48913,19612 
   signal-strength=-51dBm@1Mbps signal-to-noise=50dB 
   tx-ccq=58% p-throughput=48636 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 

11 interface=wlan1 mac-address=C0:8C:71:64:8B:8B 
   rx-rate="39Mbps-20MHz/1S" tx-rate="52Mbps-20MHz/1S" 
   frames=1586,1366 hw-frames=2517,2424 
   signal-strength=-67dBm@1Mbps signal-to-noise=34dB 
   tx-ccq=78% p-throughput=45367 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

12 interface=wlan1 mac-address=90:63:3B:11:20:BA 
   rx-rate="1Mbps" tx-rate="52Mbps-20MHz/1S" 
   frames=1968,2234 hw-frames=5151,2491
   signal-strength=-84dBm@1Mbps signal-to-noise=17dB 
   tx-ccq=54% p-throughput=40136 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

13 interface=wlan1 mac-address=94:B8:6D:DC:8E:B2 
   rx-rate="65Mbps-20MHz/1S/SGI" tx-rate="72.2Mbps-20MHz/1S/SGI" 
   frames=10275,10684 hw-frames=12796,11170 
   signal-strength=-65dBm@HT20-6 signal-to-noise=36dB 
   tx-ccq=92% p-throughput=54798 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-7" 

14 interface=wlan1 mac-address=76:C1:E8:44:D3:B9 
   rx-rate="26Mbps-20MHz/1S" tx-rate="78Mbps-20MHz/2S" 
   frames=842,2516 hw-frames=1474,3457 
   signal-strength=-61dBm@1Mbps signal-to-noise=40dB 
   tx-ccq=72% p-throughput=64454 
   tx-rate-set="CCK:1-11 OFDM:6-54 BW:1x SGI:1x HT:0-15" 
check formula for speed? https://www.hitbullseye.com/Quant/Time- ... stance.php
 
rbuserdl
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Re: WiFi limitations

Thu Jan 14, 2021 11:12 pm

Thanks a lot!!!

I just went to the place for first time and came back to my home.
There are 4 APs in different places, ussing channels 1, 6 and 11. Each AP has a different SSID
I changed to use only N and will see, I could not determine if the issue is solved because there were few people there, I want to see the behavior with more devices connected.
Something that I could see is that one of those APs was failing, no one could connect to it, so there were devices with poor signal connected to the incorrect AP, I just reboot the AP and started to work.
I also want to limit signal strenght, to avoid, for example, devices connecting with less than -70 dBm. I know how to accomplish this, I just need to speak to my boss.

Regards,
Damián
 
rbuserdl
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Posts: 175
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Re: WiFi limitations

Mon Jan 18, 2021 6:03 pm

Well, today someone told me that WiFi was working awful again.
So, I find out further, and again the same AP than before, stoped working.
When users was trying to connect to this, they got: "No es posible conectarse a esta red", thing this is something like "Could not connect to this network", without any detail.
I couldnt see anything wrong in the AP, but I updated RouterOS and Firmware to the latest version... will see.
After this, the issue seemed to persist, then I limited the signal strength up to -70 dBm and everything seems to be fine now, even speed test is giving me more bandwith than before

Related to the AP which stoped working, I dont want to create a new post because maybe with the update, it stop failing, but, if not:
Do you suggest anything to test in the AP to see why users cannot connect to this?

Thanks a lot!!!
Regards,
Damián
 
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bpwl
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Re: WiFi limitations

Mon Jan 18, 2021 7:01 pm

Check the log in the AP.
You must enable the wireless log to see more:
/system logging add topics=wireless action=memory
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