Serious problem with P2P link

RouterOS Wireless Networking
1

Hi all,

I have a very strange serious problem. I have this backbone P2P link made by 2 RB532’s / SR5. I have perfect link, 90-100 CCQ and 40-50 SNR running 6km. I run 5GHz Turbo and easily push 35Mbit UDP through it. However every 10 minutes the link stops forwarding traffic. I have wireless link and see packet RX/TX counter (Wireless frames) increase on both sides, but all L2 and L3 is gone for around 20 seconds.. Then packets starts flowing again for around 10 minutes again and it all repeats again.

Software is 2.9.41 on both sides. RB is doing only routing with 2 IP adresses on each. Both are being polled by Dude. The log shows nothing, no disconnects or anything. I am able to access both routers when link is down by another link and both RB’s responds fine on LAN side..

Anyone have a clue about this?

/Henrik

2

Have you checked the Ethernet link status on the remote side when the link dies? Maybe it is an ethernet problem rather than wireless.

3

I can access both routers when link is down from other paths via Eth.. i see registration on both sides, link is up and i see the TX/RX wireless counters go up.. Just can’t L2 ping/telnet nor L3 ping/telnet… Really strange issue.. I was thinking that the only non-standard thing about this setup is that both boxes are running on 330MHz…

/Henrik

4

radar?

5

Janisk,

Radar would change channels. I newer loose link, link stays up, just no frames get passed by it for some time and then it resumes.. However data is sent through it becausae i can see the RX/TX frame counter is increasing.

One thing i can see just before traffic stops, is that ping rises from 1-2ms to about 3-4 secs before it dies..

/Henrik

6

did a channel change do anything?

7

Nope, same issue on all stable channels with/without turbo…

/Henrik

8

I belive this is a problem in the wireless driver. See also this topic:

http://forum.mikrotik.com//viewtopic.php?p=69825#69825

In our case we had two different behaviours:

  1. the link is “unbalanced”, i.e. it works nicely on one direction and it’s crazy on the other side
  2. the bandwidth is at peak (e.g. 20Mbit half duplex) then start decreasing (e.g. 7-8Mbit HX) then it goes to zero for 5 seconds.

Please mikrotik fix it! It costed us a lot of money in trying to figure out what was wrong :frowning:

Regards.

9

Very interesting. I saw another post with some guy having the same issues today but blamed the wireless driver and periodic recalibration. I wonder if RouterOS does something with the wireless cards themselves? I have been running 3Beta6 on these boxes before and maybe that have something to do with it, even if all packages are downgraded to 2.41, however the cards have to have some kind of firmware on them to function so maybe thats the issue?

/Henrik