We recently purchased 10 Mikrotik Metal 2SHPn routers and are having many problems with every unit. I am attaching supout files for both radios. As you will see, both units have firmware version 6.17. The basic configuration of each radio is as follows:
Radio #1:
- Mode: Bridge (with ether1 and wlan1 added as ports)
- Wireless Mode: AP Bridge
- WDS Mode: Dynamic
- WDS Default Bridge: bridge1
- Band: 2GHz Only N
- Channel Width: 20/40MHz HT-Above
- Nstreme Enabled with Framer Policy set to Best Fit and Framer Limit set to default value
- Distance set to “Indoors” since actual link distance is only around 20 feet
Radio #2:
- Mode: Bridge (with ether1 and wlan1 added as ports)
- Wireless Mode: Station WDS
- Band: 2GHz Only N
- Channel Width: 20/40MHz HT-Above
- Nstreme Enabled
- Distance set to “Indoors” since actual link distance is only around 20 feet
It should be noted that the testing described below is done in a closed loop test setup in that antennas are NOT used. The two radios are connected together using 25 feet of coaxial cable plus a 90dB coaxial attenuator to reduce signal level down to desired level. This setup ensures no wireless interference from other transmitters and virtually perfect CCQ. This setup I mention has been used for more than 10 years to test many different wireless routers that we have sold including many built with Mikrotik router boards and radio cards. This setup has worked flawlessly so please do not question the integrity or validity of this setup. Also, to verify this setup is still functional, we have tried using other wireless routers we have built using the Mikrotik router boards and radio cards (versus the Metal 2SHPn) and the problem described below does not exist. In that scenario, the only thing we are swapping out if the physical wireless radios themselves. All other test fixture components including POE’s, POE cables, coaxial cables, attenuators are all unchanged. Finally, I should also say that we have not seen this problem at all on the Mikrotik Metal 5SHPn only the 2SHPn. However the problem appears to be on every unit we test. The problem also appears to be aggravated when using Nstreme. I don’t understand this because again, we do not see this problem when using say RB433AH router board with R52Hn radio card.
I also want to say that I have reloaded flash with firmware version 6.17 using Netinstall so everything is reset to factory default from the get go.
The physical test setup, from one end to the other is as follows:
“Windows XP PC -> Ethernet Cable -> POE -> Metal 2SHPn -> 90dB Attenuator -> 25 Foot Coaxial Cable -> Metal 2SHPn -> POE -> Ethernet Cable -> Windows XP PC”
When I mention below passing data across the link, this is done using “iperf” on both PC’s, which is completely independent of the network devices between the two PC’s.
The problem we are having is this:
1) Wireless link is established very easily and will stay up for indefinitely until I start passing data across the link.
2) Once I start passing data across the link, the link will drop out completely within 2 minutes and sometimes never come back up until I reboot. Other times, the link stops passing data and the Wireless Registration table shows link is still up but last activity continues to increase indefinitely.
3) While the link is running data, the Tx and Rx Signal Levels are -57/-57 and Tx/Rx CCQ is 96/100.
Disabling nstreme eliminates this problem. I have just sent email to
support@mikrotik.com. Given how long this problem has existed, based on this thread, I would certainly hope by now that Mikrotik knows about this problem and either has a fix or admits theirs and issue.
--- UPDATE ----
I just downloaded and installed 6.18 on both radios and ran the test again. Seems more stable but still have drop outs and occasionally the link freezes and never comes back up until units are rebooted as reported by others in this forum also.