Groove A-52HPn, extensive data loss

RouterOS Wireless Networking
1

Hello world !!!
I have a severe problem with mentioned Groove devices (ROS 6.7).
I installed seven of them in my site to let cusomers access the internet.
After connecting all users are connected in 30 - 90 seconds and the logs show

disconnected, extensive data loss

Wireless settings :

name="AP-1" mtu=1500 mac-address=D4:CA:6D:BF:AD:69 arp=enabled 
      disable-running-check=no interface-type=Atheros AR9300 
      radio-name="D4CA6DBFAD69" mode=ap-bridge ssid="AP-1" 
      area="" frequency-mode=manual-txpower country=germany antenna-gain=16 
      frequency=2417 band=2ghz-onlyg channel-width=20mhz scan-list=default 
      wireless-protocol=802.11 rate-set=default 
      supported-rates-b=1Mbps,2Mbps,5.5Mbps,11Mbps 
      supported-rates-a/g=6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps 
      basic-rates-b=1Mbps basic-rates-a/g=6Mbps max-station-count=2007 
      distance=1 tx-power=10 tx-power-mode=all-rates-fixed 
      noise-floor-threshold=default nv2-noise-floor-offset=default 
      periodic-calibration=default periodic-calibration-interval=60 
      dfs-mode=none 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 
      station-bridge-clone-mac=00:00:00:00:00:00 ht-ampdu-priorities=0 
      ht-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,mcs-12,mcs-13,mcs-14,mcs-15,mcs-16,mcs-17,mcs-
                 18,mcs-19,mcs-20,mcs-21,mcs-22,mcs-23 
      ht-basic-mcs=mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,mcs-7 
      ht-txchains=0 ht-rxchains=0 ht-amsdu-limit=8192 ht-amsdu-threshold=8192 
      tdma-period-size=2 nv2-queue-count=2 nv2-qos=default nv2-cell-radius=30 
      nv2-security=disabled nv2-preshared-key="" 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

Devices are directly connected to 14 dBi panels which worked with the devices installed before.
Tx-Power ist “all rates fixed” at 17 dBm
Distance is set to 1km, customers live in a distance of max. 200m
Noise Floor is -95 dBm on all devices, not changing, don´t know what this means
If a user manages to be listed under “registration”, the “P Throughput” starts with a good value,
counts down to 0 and disconnects.
Some users manage to log in an start downloads at ~3 Mbps (limited by profile) which shows, that
a bad signal might not be the cause of the disconnects.

Do you need more information ?
Please help or my customers will kill me.

THX

2

try setting the distance value to indoors if the clients are not so far away.
Also try to use b/g/n band.

3

try setting the distance value to indoors if the clients are not so far away.
Also try to use b/g/n band.

Did so, no change.

4

Is there a way to switch the wireless to be a bit more sensitive ?
With the old devices, there have always been about 5 connected client for
every AP. Everybody who walked by with a cellphone was seen by at
least one AP. On the Grooves, the registration table is empty most of the time.
Seems like the Grooves ignore most of the incoming signals.

5

Did some further testing without success.
Antennas are Hyperlink 14dB 120° flat panels where the Groove is directly conencted.

Connected users are kicked out while doing high speed downloads, so I do not think that
it is realy a problem with a weak signal (Tx/Rx Signal Strength -71dBm looks strong enough
SNR 25 dB)
P Throughput shows 41834 kbps
How can I set the Groove to not disconnect the clients and just keep them connected
even if there is data loss ? Disconnect Timeout does not do that.
Are there receiver settings somewhere ?

Looks more and more like an impossible mission to bring these things to work properly.

Any hints ?

6

Try to set the Groove on 802.11b.
You speak from 7 devices, on how much distance that from each other?

7

Devices are located on top of a building.
Two are about 15 m away from another with
an elevator house between them. The others
are in ~50m distance.
Antenna directions are set to different sectors
to not influence each other.
I do not think that interferences are the problem,
because it worked with the old WRT54GLs and
the antennas were not changed.

Will try b-mode when I am back in the office.

8

Wireless b-mode makes no change. Still extensive data loss with good signals.

Seems like the receiver unit of the devices are rubbish.

9

Try to reduce the output power on each groove.

10

I think this is the problem, especially with a 15m distance link. You might have set the power too high.

11

Set Tx to “all rates fixed” at 17 dBm (50 mW)
Still “extensive data loss” and less users connected.
I think they just cannot log in or they gave up trying.
The old devices ran at >20 dB (120 mW - 150 mW) without
negative effect to each other.

I do not think that the 15m distance has an effect
because there are two ferroconcrete wall between them
and they are mounted back to back to each other.

Just the WRTs were replaced cables removed and
Grooves directly connected, no changes to antennas,
positions or anything else. Shouldn´t new Mikrotik devices
work much better than over ten years old hardware ?

12

Can it be that the devices are connected too close to the antenna and the signals around
go straight through the plastic case and have disturbing effects the hardware of the Groove ?
I still have the shielded cases for the WRTs installed, maybe I put the Grooves into them
and connect them with a cable.
Might this be a chance ?

For now, I am running out of ideas.

I will be at the site on monday to see if I can make it work and, in worst case, install the
old hardware that worked. So, if there any further ideas, please tell me and I will test it.
It is always a not so funny day to drive 800 km to try to make something run, that produced
more loss of money in one week, than the old hardware had gains in one month.

13

try setting the hw-retries to 15 and check if that improves the situation.
Also make a support output file and send it to support@mikrotik.com for inspection of the wireless configuration and registration table.

14

Setting hw-retries was one of my first steps to make the antenna work a bit less restrictive, but it did not change a lot.
Will try a supout and see if they can help me.

15

Sent a spuout, but think that I will not get any answer (Support only for paying customers)
The guy from my reseller will not help me. I met him at the CEBIT, not a nice guy.

Looks like going back to WRT

16

Did you send a supout to Mikrotik support or to that guy that wasn’t very nice? :slight_smile:

17

Please reset the wireless interface to default configuration. Here is example how to do that:
/interface wireless reset-configuration wlan1

After that change the configuration that you only need, like country,ssid,frequency,security-profile and then check how it is working.
If you still see some problems, make a support output file and send it to support@mikrotik.com

18

hi…

any progress on your problem???

19

Every time I replace an old board like 133 or 433 with a Groove I notice huge improvement in signals - between 5dB to 10dB on received signal and even more on Tx. I guess this is mainly from removing all cables.
So with that in mind even by reducing the tx-power to 17dBm and your antennas - 14dBi, I still think the signal is too strong for this distance. I have clients on 1-2km with signals in the -60s.
Also besides ‘hw retries’ try increasing the ‘disconnect timeout’

20

i think this should solve the problem…

goto INTERFACE → WIRELESS → SECURITY PROFILE → GROUP KEY UPDATE

change the value from 00:05:00 to 01:00:00

i think this should help in keeping the clients connected.