Hola!

I think you're mixing "physical link", (layer 1 = radio) with Layer 2.

I'm not sure what do you mean with "NV2 transmission rate", if you meant how to fix a given MCS, that's done indepently from NV2.

I'd bet when your NV2 shows varying CCQs, radio rates are also changing, isn't it?

Also bear in mind that for NV2 CCQ rates to be useful, traffic must be passing thorugh the link, as it does its calculations based on actual traffic.

Regarding 5, there's no such "protocol" per se apart from 802.11n or whatever you are using. But, both nstreme and NV2 need near to perfect link (L1) conditions to do their job; if CCQ goes below 90 in regular 802.11a/n using nstreme or NV2 on top will probably do more harm than good, as as soon as you have lost frames and need lots of retransmission TDMA will be screwed.

In such situation the first goal is to stabilize the link in L1 (radio) terms; it could be the channel used, the antenna used, the height...

name="wlan1" mtu=1500 mac-address=XX:XX:XX:XX:XX:XX arp=enabled disable-running-check=no 
      interface-type=Atheros AR9888 radio-name="XXXX" mode=station ssid="XXXX" area="" 
      frequency-mode=superchannel country=no_country_set antenna-gain=0 frequency=5180 
      band=5ghz-a/n channel-width=20mhz scan-list=default,complete-channels wireless-protocol=nv2 
      rate-set=configured supported-rates-a/g="" basic-rates-a/g="" max-station-count=2007 
      distance=dynamic tx-power-mode=default dfs-mode=none vlan-mode=no-tag vlan-id=1 
      wds-mode=disabled wds-default-bridge=none wds-default-cost=100 wds-cost-range=50-150 
      wds-ignore-ssid=no update-stats-interval=disabled bridge-mode=enabled 
      default-authentication=yes default-forwarding=yes default-ap-tx-limit=0 
      default-client-tx-limit=0 proprietary-extensions=post-2.9.25 wmm-support=disabled 
      hide-ssid=no security-profile=default disconnect-timeout=3s on-fail-retry-time=100ms 
      preamble-mode=both compression=no allow-sharedkey=no 
      ampdu-priorities=0 guard-interval=any 
      ht-supported-mcs=mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,mcs-7,mcs-8,mcs-9,mcs-10,mcs-11 
      ht-basic-mcs=mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,mcs-7 
      vht-supported-mcs=mcs0-9,mcs0-9,mcs0-9 vht-basic-mcs=mcs0-7 tx-chains=0,1 rx-chains=0,1 
      amsdu-limit=8192 amsdu-threshold=8192 tdma-period-size=2 nv2-queue-count=2 nv2-qos=default 
      nv2-cell-radius=30 nv2-security=enabled  hw-retries=7 
      frame-lifetime=0 adaptive-noise-immunity=none hw-fragmentation-threshold=disabled 
      hw-protection-mode=none hw-protection-threshold=0 frequency-offset=0 rate-selection=advanced 
      multicast-helper=default multicast-buffering=enabled keepalive-frames=enabled 

Keep in mind you cannot "fix" the MCS in the stations. Only in the AP.

NV2 has nothing to do with MCS settings.

You can monitor the MCS rates in Wireless > Registration.

suerte!

/interface wireless registration-table print stats
rx-rate="130Mbps-20MHz/2S" tx-rate="130Mbps-20MHz/2S/SGI"
tx-rate-set="OFDM:6-54 BW:1x SGI:1x HT:0-15"

That's the actual negotiated MCS. 130Mbps-20MHz SGI = MCS14

You have MCS 0-15 as available.

There's a MCS table in the Wikipedia.

Keep in mind AP will select a lower MCS if the highest one set cannot be stablished reliably.

I guess what you want to do is set a lower MCS so that connections are stablished reliably?

P.S. De dónde eres?

That's the actual negotiated MCS. 130Mbps-20MHz SGI = MCS14

You have MCS 0-15 as available.

There's a MCS table in the Wikipedia.

Keep in mind AP will select a lower MCS if the highest one set cannot be stablished reliably.

I guess what you want to do is set a lower MCS so that connections are stablished reliably?

P.S. De dónde eres?

Hi again!

From the table, How do yo know that the MCS is 14. I think that it is MCS 15 because of from Mikrotik Wiki: "ht-guard-interval (any | long) [NV2 only supports 800nS long guard interval!]"

Anyway, YES, what I want to do is to set a Lower MCS / data rate / whatever to have a reliably connection ... is it possible with NV2?

The problem of fixing MCS with NV2 is what made me think that the Layer 2 and 3 are connected in this way...

PS: De Córdoba, tu?

Where have you read NV2 only supports long GI? GI has nothing to do with NV2 TDMA...

As far as I know, (correct me if I am wrong) the decision to choose a MCS relies mainly on the S/N ratio. The problem is, in non optimal situations maybe there is a good S/N ratio but the actual CCQ is low because, for example,
multipath reflections are causing retransmissions.

In that case you may experience a "jumping" MCS issue. The units keep selecting a high MCS, going back to a lower one when retransmissions occur. It can lead to higher delays than simply setting a lower MCS.

In my case, doing this works like a charm:

Code: Select all

ht-basic-mcs=mcs-11 ht-supported-mcs=mcs-11

When trying any higher values it almost imediately fell back to a lower value and the CCQ went down. With this, CCQ remains above 90%, generally close to 100%.

 0  R name="wlan1" [b]mode=bridge[/b]
      band=5ghz-a/n/ac channel-width=20/40mhz-Ce scan-list=default,complete-channels 
      wireless-protocol=nv2 rate-set=configured 
      supported-rates-a/g=6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps 
      basic-rates-a/g=6Mbps max-station-count=2007 distance=dynamic tx-power-mode=default 
      dfs-mode=none vlan-mode=no-tag vlan-id=1 wds-mode=disabled wds-default-bridge=none 
      wds-default-cost=100 wds-cost-range=50-150 wds-ignore-ssid=no update-stats-interval=disabled 
      bridge-mode=enabled default-authentication=yes default-forwarding=yes default-ap-tx-limit=0 
guard-interval=any 
      [b]ht-supported-mcs=mcs-2 ht-basic-mcs=mcs-2[/b] vht-supported-mcs=mcs0-9,mcs0-9,mcs0-9 
      vht-basic-mcs=mcs0-7 tx-chains=0,1 rx-chains=0,1 amsdu-limit=8192 amsdu-threshold=8192 
      tdma-period-size=2 nv2-queue-count=2 nv2-qos=default nv2-cell-radius=30 nv2-security=enabled 
   

 0  R name="wlan1" mode=station
      band=5ghz-a/n/ac channel-width=20/40mhz-Ce scan-list=default,complete-channels 
      wireless-protocol=nv2 rate-set=configured 
      supported-rates-a/g=6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps 
      basic-rates-a/g=6Mbps max-station-count=2007 distance=dynamic tx-power-mode=default 
      dfs-mode=none vlan-mode=no-tag vlan-id=1 wds-mode=disabled wds-default-bridge=none 
      wds-default-cost=100 wds-cost-range=50-150 wds-ignore-ssid=no update-stats-interval=disabled 
      bridge-mode=enabled
     guard-interval=any 
      [b]ht-supported-mcs=mcs-2 ht-basic-mcs=mcs-2[/b] vht-supported-mcs=mcs0-9,mcs0-9,mcs0-9 
      vht-basic-mcs=mcs0-7 tx-chains=0,1 rx-chains=0,1 amsdu-limit=8192 amsdu-threshold=8192 
      tdma-period-size=2 nv2-queue-count=2 nv2-qos=default nv2-cell-radius=30 n hw-retries=7 frame-lifetime=0 
      adaptive-noise-immunity=none hw-fragmentation-threshold=disabled hw-protection-mode=none 
      hw-protection-threshold=0 frequency-offset=0 rate-selection=advanced multicast-helper=default 
      multicast-buffering=enabled keepalive-frames=enabled 

Good day, my satuation is 4 km link , I use ap bridge in side and the other side station wds, with nv2 I had ccq less than 90 and sometimes it goes over, with 802.11 I get ccq over 90 mostly and even 100/100 sometimes.

Good day, my satuation is 4 km link , I use ap bridge in side and the other side station wds, with nv2 I had ccq less than 90 and sometimes it goes over, with 802.11 I get ccq over 90 mostly and even 100/100 sometimes.

As stated earlier: Both nstreme and NV2 need stable, near to perfect link (L1) conditions to do their job; if CCQ goes below 90 in regular 802.11a/n using nstreme or NV2 on top will probably do more harm than good, as as soon as you have lost frames and need lots of retransmission TDMA will be screwed.

Please notice that I have set the "mcs-2" ...and if I run a Bandwitdh-test and monitor at both sides I get:
tx-rate: 216Mbps-40MHz/2S
rx-rate: 130Mbps-20MHz/2S/SGI
and even more....

What I'm doing wrong with configuration?

did you untick unwanted MCS in the HT-MCS tab??

¿Son equipos 802.11ac nuevos? En ese caso NO puedes fijar las velocidades. Era posible en los 802.11n. Limitaciones del chipset.

Please notice that I have set the "mcs-2" ...and if I run a Bandwitdh-test and monitor at both sides I get:
tx-rate: 216Mbps-40MHz/2S
rx-rate: 130Mbps-20MHz/2S/SGI
and even more....

What I'm doing wrong with configuration?

New 802.11ac units? I think that due to a limitation in the chipset you can't limit the MCS modes used. My configuration works on old OmniTIK units (802.11n).

Y saludos de Bilbao

I think someone from MikroTik said that he could not fix. It's a given from AC hardware ...

I think someone from MikroTik said that he could not fix. It's a given from AC hardware ...

You are mistaking .n and .ac with nstreme, nv2.
802.11ac cannot be set to exact MCS and this is actually part of the protocol itself. You can however set the maximum MCS from Data Rates -> Configured -> VHT, but not less than MCS0-7. If you switch to .n then you can set an exact MCS from Wireless -> HT MCS (you still need to set Data Rates to configured).
This has nothing to do with 802.11, nstreme or nv2.