Hi Everyone,

I have a LOS between these two points (PTP) about 1KM ... both are running 433AH and they are capable to perform 10Mbps 2 ways using TCP bandwidth test.

signal to noise 59 dB
noise floor -95 dBm
tx/rx signal strenght -45 / -38 dBm
overall Tx CCQ - 89 to 100%

Nstreme has been enabled with disable CSDMA

Any help is very much appreciated.

Thank you!

What are the bandwidth test settings? Are you doing a TCP+Both directions test?

To test the true wireless bandwidth, test UDP+send or UDP+receive only. Wireless is half duplex, therefore by doing a TCP test you are halving the bandwidth shown, since TCP ACKs are not counted.

10 Mbps is 2 way TCP tests

16Mbps if it is UDP 1 way (send or receive)

I wonder how i could improve the performance.

Thank you

Give us some more info about your setup. wireless interfaces, antennas, cable lengths, etc.

your tx/rx signal is mismatched. If you're using the same wireless interfaces, same tx powers and same antennas, these two should be the same.

And, while I never had this problem myself, -38dbm is a bit on the high side and might cause distortion at the receiving end, try lowering the tx power of the side tx'ing at that level.

Hi Andrea,

Both are using identical antenas, wireless interface and routerboard 433 AH

this info

tx/rx : -45/-37 dBm is taken on the station wds

so -45 is the signal strength on the station wds and -37 is on the other side (the ap bridge)?

in this case i need to adjust the power on the ap bridge? (lower or higher?)

Thank you!

yes, you need to adjust the ap-bridge side. Lower it by around 5-10db.

However if you're using identical setups on both ends, something is clearly wrong as you shouldn't have that much of a discrepancy between the tx and rx.

Tried replacing the wireless interface on the station side?

Hi Andrea,

Should i set to all rates fixed to 10?

Thank you

I just set it to 10 for the TX power and lost the link.

Our guy is going to the site at the moment.

Hmm.. I guess you didn't use Safe mode then..

there must be something wrong with your link, probably hardware.

wow ... i did not know about safe mode untill now!

I cant find any documentation about it.

Do you have any link?

TIA!

hit CTRL+X in the terminal window of winbox. hit the same combination to turn it off. during safe mode, router will make sure you don't lose connectivity to winbox, if you do, it will Undo the last command.

Normis,

That is a pretty neat tool!

I wont afraid of losing connectivity now!!!

Just to clarify:

it won't undo just the last command. It will revert the router back to the configuration it had when you hit CTRL+X.

in other words, if you do this:

/interface wireless set wlan1 mode=ap-bridge
then
/interface wireless set wlan1 mode=station
then you press CTRL-X, so you are now in safe mode...
then
/interface wireless set wlan1 mode=bridge
then
/interface wireless set wlan1 mode=station-wds
then your Winbox disconnects...

in that case, the wireless interface will revert back to mode=station.

yes, http://wiki.mikrotik.com/wiki/Console#Safe_Mode

What are the bandwidth test settings? Are you doing a TCP+Both directions test?

To test the true wireless bandwidth, test UDP+send or UDP+receive only. Wireless is half duplex, therefore by doing a TCP test you are halving the bandwidth shown, since TCP ACKs are not counted.

Assuming a unidirectional TCP test (TCP receive or TCP send), the bandwidth consumed by the ACKs is nowhere near the bandwidth consumed by the test data in the other direction. There is a performance hit taken by the radios needing to stop receiving to transmit the ACK frames, but it's not even close to 50%, it's more in the neighborhood of 2-5%.

UDP tests are good for determining the maximum successful capacity of a link. A 100Mbps capacity link with 50% packet loss will show an average of near 50Mbps with UDP, but a TCP test will react to the packet loss as congestion and keep backing off, resulting in an essentially unusable link.

Use UDP and TCP tests to test different characteristics of the same link.