Hi,

I just setup new link between two buildings using RB411AH + R52H + Flat 20dB Antenna.
The distance is 15 meter..yes, only 15 meter. I wish I could pull a cable between the building through the window at 19th floor but it is not allowed.

The Topology:
PC---RB411AH(AP) - - - RB411AH(station)---FTP_Server

The setup on both device are:

ROS v3.30 with wireless-test package used.
AP Bridge vs Station
Simple static routing (no bridge)
Freq: 5Ghz
Nstreme: No
WDS: No
HW retries : 4
TX Power Mode : Card Rate 19 dBm

And the status shown :
Signal : -25dB
TX Signal : -25dB
Signal to Noise : 77dB
TX/RX Rate : 54Mbps/54Mbps
TX/RX CCQ : 90%/90%
ACK : 28 us

When I tested the link by upload and download from PC to FTP server the result are :
TX is around 20-23 Mbps and very stable.
RX is around 18-20 Mbps and very stable.
Ping Latency on bandwidth peak : 20-35ms.

CPU load is only 15-25% on both 411AH.
Free memory size : 51 MiB

When I used Bandwidth Tester between the PC to RB411AH eth port, the result are:
Send Only : 65Mbps
Receive Only : 90Mbps

I just wonder, is the wireless link result normal ? I mean, with a lot of free resource like that, why the bandwidth can not go further than 23Mbps ? What factor limit the link ?

I know i can use Nstreme or 5Ghz turbo on the link to get more bandwidth. I just need an explanation what things that limit the link to get more bandwidth for the current setup.

BTW, I attached the supout in case Mikrotik support need it.

And below are the setup on the devices:

[admin@Station] /interface wireless> pr advanced
Flags: X - disabled, R - running
0 R name="wlan1" mtu=1500 mac-address=00:0C:42:68:85:AA arp=enabled
disable-running-check=no interface-type=Atheros AR5413
radio-name="000C426885AA" mode=station ssid="Test1N" area=""
frequency-mode=manual-txpower country=no_country_set antenna-gain=0
frequency=5280 band=5ghz scan-list=default 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
ack-timeout=dynamic tx-power=19 tx-power-mode=card-rates
noise-floor-threshold=default periodic-calibration=default
periodic-calibration-interval=60 burst-time=disabled dfs-mode=none
antenna-mode=ant-a wds-mode=disabled wds-default-bridge=none
wds-default-cost=100 wds-cost-range=50-150 wds-ignore-ssid=no
update-stats-interval=disabled 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 hw-retries=4
frame-lifetime=0 adaptive-noise-immunity=none


[admin@APBridge] /interface wireless> pr advanced
Flags: X - disabled, R - running
0 R name="wlan1" mtu=1500 mac-address=00:0C:42:68:8C:61 arp=enabled disable-running-check=no interface-type=Atheros AR5413 radio-name="000C42688C61"
mode=ap-bridge ssid="Test1N" area="" frequency-mode=manual-txpower country=no_country_set antenna-gain=0 frequency=5280 band=5ghz scan-list=default
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 ack-timeout=dynamic tx-power=19 tx-power-mode=card-rates noise-floor-threshold=default
periodic-calibration=default periodic-calibration-interval=60 burst-time=disabled dfs-mode=none antenna-mode=ant-a wds-mode=disabled
wds-default-bridge=none wds-default-cost=100 wds-cost-range=50-150 wds-ignore-ssid=no update-stats-interval=disabled 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 hw-retries=4 frame-lifetime=0 adaptive-noise-immunity=none


Thank you
Aldhy SP

You need to turn the power down or you are going to ruin your cards.

23Mbps is about what to expect from an optimal 802.11a link.

Yes. Turn down the power until it is in the -50s. That is more thn enough for optimal performance.

@popcorrin & colebert

Thank you for your suggestion. I'll to turn down the power once I arrive at my office. BTW, will it make the bandwidth better?
Or 23Mbps is the max for RB411AH without Nstreme and 5Ghz Turbo?

Thank you
Aldhy SP

@popcorrin & colebert

Thank you for your suggestion. I'll to turn down the power once I arrive at my office. BTW, will it make the bandwidth better?
Or 23Mbps is the max for RB411AH without Nstreme and 5Ghz Turbo?

Thank you
Aldhy SP

23-24Mbps is pretty much the max for the protocol without using something like Nstreme to reduce overheard.

tx power is too high...

@popcorrin & colebert

Thank you for your suggestion. I'll to turn down the power once I arrive at my office. BTW, will it make the bandwidth better?
Or 23Mbps is the max for RB411AH without Nstreme and 5Ghz Turbo?

Thank you
Aldhy SP

for 20Mhz 54/2=27mbps so this is the max. speed you can get.
for 40Mhz your link can go up to 80-85mbps with nstreme and disable csma.

@popcorrin & colebert

Thank you for your suggestion. I'll to turn down the power once I arrive at my office. BTW, will it make the bandwidth better?
Or 23Mbps is the max for RB411AH without Nstreme and 5Ghz Turbo?

Thank you
Aldhy SP

for 20Mhz 54/2=27mbps so this is the max. speed you can get.
for 40Mhz your link can go up to 80-85mbps with nstreme and disable csma.

You mentioned is from the Btest or the Real time traffic?
80~85Mbps is the TCP or UDP?

Switch to two antennas or a dual polarity antenna at each end and an R52n of you want to go faster.

Then run this in 802.11n mode only with dual MIMO.

Go look at the 802.11n forum thread for more details.

Tom

@popcorrin & colebert

Thank you for your suggestion. I'll to turn down the power once I arrive at my office. BTW, will it make the bandwidth better?
Or 23Mbps is the max for RB411AH without Nstreme and 5Ghz Turbo?

Thank you
Aldhy SP

for 20Mhz 54/2=27mbps so this is the max. speed you can get.
for 40Mhz your link can go up to 80-85mbps with nstreme and disable csma.

You mentioned is from the Btest or the Real time traffic?
80~85Mbps is the TCP or UDP?

TCP real traffic, RB411/RB433 and CM9/R52.

I'm working through a throughput scenario so let me see if I have this right. on an xr5 setup. pick a channel with adequate spacing for turbo (40mhz) I choose 5785 (40mhz to the edge at 5825 and 40mhz plus space below.) turn on n-stream, disable csma at the ap end and far end will automatically adjust and set the band to 5ghz turbo. Is that it?

You will have to change the other side first, then change the side you are on.

I have a script that someone on the forum made, changes between 2.4GHz B/G, 10MHz and 5MHz, with and without Nstreme until the system gets a link again.

I have been unable to modify the script successfully and change it to 5GHz. I need to stop and take some time and figure out what I did wrong.