Throughput vs. ACK Timeout/Distance (MT-UBNT)

RouterOS Wireless Networking
1

I wanted to share some interesting elements that I have noticed on a 27 kilometers link recently installed by myself.

Summary: PTP link | Master - MT 433 (6.0rc9) with XR2, Slave - UBNT Bullet2HP (XS2.ar2316.v4.0.2.4996.120423.0955) | 802.11b | signal Tx/Rx -68/-67 dBm | noise floor -99dBm | signal to noise 30 dB

  1. At the beginning, I established a fixed ACK Timeout/Distance on both side with 27 kilometers and I was having a ~ 3.5 Mbps throughput rate. However, after selecting dynamics on the MT unit and activating the auto adjust on the UBNT unit, my rate has improve immediately to 7.2 Mbps.

  2. I also noticed that during no data transfer, my Rx/Tx CCQ is ~33/100% but when I start transmitting it goes up to 100/100%. (?)

Any thoughts?

Thanks

2

I’ve noticed that on 802.11b connections.

I’ve had better luck unchecking all of the B rates but 1Mb and using the G rates on most of my links. Also seems to work better if you limit the max speed to the highest speed that you get 100% CCQ on. I’ve got a 24 mile link that has 100% CCQ @ 24Mbps. I figured I’d try 36Mbps just to see, CCQ went down, link was stuck at 18Mbps most of the time. Unchecked 36Mb again and 24 is rock solid.

Trying to negotiate the link to 36Mb apparently caused the CCQ to drop enough that it went to 18Mb to be stable.

3

Thanks buddy.

I have done your advice, but I get a lower signal-to-noise rate 10dB instead of ~25-30 dB and the same situation that I explained before with the CCQ. On the other hand, I do get a higher throughput rate.

I am attaching the profile link just to provide more detailed info.
PTP_linkprofile2.jpg
PTP_linkprofile.jpg