Hello,

I need to build a wireless last mile between two buildings (distance <200m, some trees between) so I've bought two MikroTIks QRT 2 and connected them to each other. As a result, I have ~-32 dBm signal strength and ~60 dB signal to noise. TCP throughput is about ~60 Mbps but delay is going up and down between 5 and 700 ms. Jitter is going worse with some traffic on channel. I tried to use 802.11, nv2, nstream, tried to gain antenna up to 30 dB etc. But all of my attempts seemed helpless.

Could somebody help me with jitter, please? I think it will be great if jitter is at least ~30-50 ms.

Hello,

I need to build a wireless last mile between two buildings (distance <200m, some trees between) so I've bought two MikroTIks QRT 2 and connected them to each other. As a result, I have ~-32 dBm signal strength and ~60 dB signal to noise. TCP throughput is about ~60 Mbps but delay is going up and down between 5 and 700 ms. Jitter is going worse with some traffic on channel. I tried to use 802.11, nv2, nstream, tried to gain antenna up to 30 dB etc. But all of my attempts seemed helpless.

Could somebody help me with jitter, please? I think it will be great if jitter is at least ~30-50 ms.

try disabling 64 qam data-rates, to force the use of 16qam data-rates of course it will lower the throughput but maybe help to lower the latency.

maybe lowering the power can help i think QRT is oversized to a 200 meter link try using 5db of tx power

Many thanks, seems helpfully. Jitter is ok. But sometimes delay grows up to 9 second:

1508 bytes from 172.28.4.4: icmp_seq=422 ttl=64 time=7.680 ms
1508 bytes from 172.28.4.4: icmp_seq=423 ttl=64 time=10.108 ms
1508 bytes from 172.28.4.4: icmp_seq=424 ttl=64 time=25.400 ms
1508 bytes from 172.28.4.4: icmp_seq=425 ttl=64 time=15.737 ms
1508 bytes from 172.28.4.4: icmp_seq=426 ttl=64 time=8.262 ms
1508 bytes from 172.28.4.4: icmp_seq=427 ttl=64 time=7.197 ms
1508 bytes from 172.28.4.4: icmp_seq=429 ttl=64 time=9079.590 ms
1508 bytes from 172.28.4.4: icmp_seq=430 ttl=64 time=8158.682 ms
1508 bytes from 172.28.4.4: icmp_seq=431 ttl=64 time=7179.158 ms
1508 bytes from 172.28.4.4: icmp_seq=432 ttl=64 time=6191.234 ms
1508 bytes from 172.28.4.4: icmp_seq=433 ttl=64 time=5233.585 ms
1508 bytes from 172.28.4.4: icmp_seq=434 ttl=64 time=4258.723 ms
1508 bytes from 172.28.4.4: icmp_seq=435 ttl=64 time=3274.799 ms
1508 bytes from 172.28.4.4: icmp_seq=436 ttl=64 time=2285.465 ms
1508 bytes from 172.28.4.4: icmp_seq=437 ttl=64 time=1331.020 ms
1508 bytes from 172.28.4.4: icmp_seq=438 ttl=64 time=582.682 ms
1508 bytes from 172.28.4.4: icmp_seq=439 ttl=64 time=227.713 ms
1508 bytes from 172.28.4.4: icmp_seq=440 ttl=64 time=11.769 ms
1508 bytes from 172.28.4.4: icmp_seq=441 ttl=64 time=8.193 ms
1508 bytes from 172.28.4.4: icmp_seq=442 ttl=64 time=10.281 ms
1508 bytes from 172.28.4.4: icmp_seq=443 ttl=64 time=12.920 ms
1508 bytes from 172.28.4.4: icmp_seq=444 ttl=64 time=23.483 ms
1508 bytes from 172.28.4.4: icmp_seq=445 ttl=64 time=14.093 ms
1508 bytes from 172.28.4.4: icmp_seq=446 ttl=64 time=15.224 ms

What could be the reason for such delay from time to time?

Definately don't use 802.11. Try nv2 and another channel.