Annoying "control frame timeout" with RB SXT

brainy · July 12, 2011, 7:54pm

Hi there,

we have a PTP Link (nv2) with two RB SXTs. Distance is about 400m, LOS, CCQ 99-100%. (Total) Signal strenght is -57dB (chain0 is ~4-5dB better than chain1). The link is working great. We run a (limited to 95M in both directions) bandwidth test thru the two SXTs and everything is working fine. We reach 100% of the bandwith (95Mbps). Then suddenly (after some hours) the link dropped (the AP shows a “control frame timeout” and the Client also shows a “control frame timeout”). The noisefloor is -115dB, there are only 3 5Ghz networks in our area but on other channels. There is no overlapping in the frequency).

I have no idea what is causing this disconnect that is only happening (as i can see) during high load on the link.

Any ideas?

Regards,
Joerg

rpingar · July 13, 2011, 5:59am

we note this beavior when the signal is better than -60. Infact in some cases when you use nstreme or nv2 with 2 chain we get the links disconnecting time to time.
Using only one chain woraround the problem (if you don’t need high bandwidth).
or lower the power on both side to have -65.

regards
Ros

brainy · July 13, 2011, 4:58pm

Hah, i changed TX power from default (23db) to card rates (18db) … now i run a BW/test sind over 6 hours without any disconnect!!

Really nice! Thanks

rpingar · July 13, 2011, 5:01pm

a karma is appreciated!

regards
Ros

dzieva · July 14, 2011, 12:50am

We are having the same problem.

boomdv · July 24, 2011, 5:21pm

Me too.

pizzulicchio · February 13, 2012, 2:10pm

i’m testing two rb sxt and i can reach 95/100 mbit in UDP…
But what is the real throughput in tcp?

I’m testing a wireless p2p link of 250/300 meter( bridge–>station bridge ) but i can’t reach more than 40 Mbit in tcp. ( transfering files from a pc directly connected to SXT 1 and another one conneccted to SXT 2 )

The link quality is very good, it’s about -44/48 db
Both chain are aligned to 300Mbit…

200 mbit reported from mikrotik are in udp ? ( 100 up and 100 down ? )

Router os version is 5.12

Chewers · February 13, 2012, 5:37pm

What happens when u generate BT traffic on 3rd party device - ect. iperf or Mikrotik BTest?

pizzulicchio · February 13, 2012, 9:41pm

What do you mean by saying: “what happens?”

i have tested only transfering large single files ( dvd.iso or .mkv files ) in one direction a time and i can’t reach more than 35/40 mbit of tcp throughput.

Chewers · February 13, 2012, 9:48pm

Are u using encryption? if u do - use AES

pizzulicchio · February 13, 2012, 10:30pm

no encryption at the moment… i’m still testing…

brainy · February 14, 2012, 7:54am

Try to lower your TX-power so that signal is between -55 and -60 and do your tests again.

uldis · February 16, 2012, 3:17pm

also if you experience the control frame timeout problem, please contact support@mikrotik.com, we could provide you with a test package that might solve your problem.

pizzulicchio · February 16, 2012, 4:37pm

What “know” proble is it the control frame timeout?

Where is described?

pizzulicchio · March 2, 2012, 10:19am

Hi.
I have updated yesterday the router os to 5.14 and finally i have tested and resolved my “max throughput” trouble!

Now I can reach 80 Mbit in TCP using this settings.

( using NSTREAM instead of NV2 )

I hope this can be useful to other people.
RB SXT 80Mbit tcp.jpg

Chewers · March 2, 2012, 3:28pm

And what speed goes through if all 0-7 ht ampdu priorities enabled?

pizzulicchio · March 3, 2012, 8:34am

Using all 0-7 ht ampdu priorities enabled i gain others 4 - 6 Mbit!

The latency too is very very good. During the transfer of 80 Mbit pinging the 2 radios is about 2.20 / 2.60 msec without interruption or peak.
RB SXT 86Mbit .jpg

nio · March 13, 2012, 7:52am

I have “control frame timeout” problem too.

I had two RB SXT using nv2. I can reach any singal strength playing w/ Tx power. From -50 to -65. It works the same way whatever i set, “control frame timeout” is still w/ me.

Now i have OmniTik w/ SXT but the same thing in client SXT log “control frame timeout”.

Please help me! It’s killing me. I tryed all i can think. May be use nstream like pizzulicchio did? There are no disconnect anymore?

Station bridge is OmniTik.
Client bridge is SXT.
Both runing OS v 5.14.
I have average tcp bandwidth 45Mbps using nv2 both send/recieve.
The same i had using two SXTs.

Thanks.

brainy · March 13, 2012, 8:00am

Try the following: Set rates to “configued” and check MCS only till 12 and do not use MCS 13, 14 and/or 15 .. this will reduce bandwidth to 180Mbit/s air-rate .. but just test if this will fix the problems.

Regards, Joerg

nio · March 13, 2012, 9:01am

Thanks, done, however i don’t believe this helps… Will monitor for few days. And my Tx/Rx rate is still 300/300 Mbps. What really MCS do? I google a bit, but don’t found any descriptions how MCS checked values affect microtik work…