TX rate drop with non-mikrotik endpoints.

RouterOS Wireless Networking
1

Hi.

I have some routerboards here. I try to explain why TX rate control is differs from others in mikrotik.

Explain these situations:

Laptop with windows <----> Mikrotik AP.

Laptop transmits to MT AP at 54M rate. Mikrotik transmits at 54M too. I begin a file transfer, laptop stays @54M, mikrotik slowly drops to 2M! First it drops to 36M, 24M, … and slowly to 2M. If i have a good day, MT might switch up to 11M Short Preamble, but this is not always the case. Signal strength or SNR is NOT the problem. The problem begins with CCQ drops to 20%, even if this router near my laptop and laptop has -20 or -30 signals. If i simply reconnect, CCQ gets back to 100% and TX rate stays at 100% for a while, then problem starts from the beginning, ccq dropping down, AP tx-rate going down…

I can’t imagine what’s going on there.. I tried several other devices, still same. I switched the scenario to this:

Another AP <----> Mikrotik AP as station.

Situation is same. AP near the Mikrotik AP(station), signal, SNR good, CCQ gets down, then TX rate gets down. AP send data to mikrotik @54M, mikrotik does not want this, drops TX rate down to 2,5,11M, it’s random..

Then i went to check this out with openwrt. I’ve installed OpenWrt to my RB493AH. With OpenWrt, it works good, with any other device, TX rate DOES NOT drops, and i have stable connection.

However, i don’t like openwrt as mikrotik, so i want to figure out why mikrotik AP decides to DROP tx rates.

I tried to mess with frequencies, A/G mode, RTS/CTS, WMM, hw retries at 15, 7, ANI, etc.. Seems has no effect to this issue, it’s always doing same TX rate slowdown.

Do you have any tip?

PS: I’m using 5.0rc11, but this issue exists in previous versions too, such as 3.xx, 4.xx.

Thanks.

2

Hi Guys,

I am having similar issues with an SXT RB 5nD r2

Im doing a bandwidth test

SXT (In question doing Bandwidth Test) -----> Sector Antenna with Mikrotik board ------> RB2011Uias (PPPOE Server) - Another Mikrotik serving as BT Server

The SXT and Sector Antenna are 20 meters apart

without BT Test on
Tx/RX Signal = -60dBm/-60dBm
SNR 54 dB
Tx/Rx CCQ = 20/60%

with BT Test on TCP Receive
Throuoghput around 3mbps
Tx/RX Signal = -60dBm/-60dBm
SNR 54 dB
Tx/Rx CCQ = 50/50%

with BT Test on TCP Send
Throuoghput around 170kbps
Tx/RX Signal = -60dBm/-60dBm
SNR 54 dB
Tx/Rx CCQ = 2/50%

Why would that be, they are pointing at one another.
I have tested another SXT as well same result…

3

Good day!
I apologize in advance if this question has already been featured here.
The question is quite touchy and needs a qualitative response.
I understand that Mikrotik is used mainly in the more industrial purposes. However, many of my friends have a problem along the following lines: a laptop connected to Wi fi (n-standard distance of ~ 5-10 m) to RB951G-2HnD Routerboards. Server connection speed tester connected to the same RB951G-2HnD 1 Gbit / s. Test your connection speed always gives different readings from 0 up to 65 Mbit / s.
Indicators in the Asus router from 80 to 90 Mbit / s.

In this regard, at industrial scale, many opt for the “Unification”.

I confirm that the Wi fi connection “Mikrotik Mikrotik,” the channel is not observed huge deflection of the link.

The relevant question: how representative Mikrotik or RouterBOARD can comment on these issues?