Just recently found out the new NV2 developments in sync and up/download ratio distribution. So decided to do some tests in the field since this is what we have been waiting for!
Well, don’t work well.
Setup:
One tower, two SXT SA5 (SXT G-5HPnD r2) as AP some meter separated on same mast. Both looking in their own direction so their spread is sort of side by side.
Both by short ethernet cable connected to an Omnitik that serves as powersupply/controller (and in case of need a spectral scanner since ‘ac’ units still can’t do that…)
Same Omnitik also serves one QRT-ac for backhaul.
ORT, Omnitik and both SXT’s all in the same IP network. All fully bridged.
Clients of both AP’s mainly SXT’s lites ‘n’ protocol with a single ‘ac’ unit and 2 or 3 911’s-5Hnd in a box)
All clients connect with at least -65dBm or better.
All clients have an pppoe-client on the wlan1 interface for client authentication.
All clients have an vlan on the wlan1 with dhcp-client for local P2MP network for easy telnet and bandwidt test etc.
DHCP server sits on same vlan interface of the QRT so network speedtests (tcp, 1 stream) can be made to the QRT to test the download traffic between this QRT via de Omnitik (has weak cpu) and the SXT-SA. So we can test the ‘real’ network download speed.
Both SXT-SA’s are in 20/40MHz eC, nv2 protocol and all further paratmeters the same except the SSID off course.
ALL units are upgraded to ROSv6.40.1 before tests.
We used the Omnitik to make a spectral scan to pick the frequencies with lowest interference from other Wifi. (All 5Ghz band!)
Both SXT-SA’s have their own working channel. AP-A has 5465 and AP-B has 5575 and according Omnitik both have -70 - -75 as background noise.
Frequency spacing between both is therefore 70Mhz
First we do the test as stand alone AP’s.
On both AP’s we pick a client for the test and run the tcp bandwidth test to the QRT with 1 chain.
On both AP’s we reach speads of about 40 to 50Mbps download. (Not at the same time, first client of AP-A, then client of AP-B)
Then we setup AP-B as sync master with sync secret as per wiki (https://wiki.mikrotik.com/wiki/Manual:Nv2#Nv2_AP_Synchronization)
We then also setup AP-A as sync slave according same manual and make sure the channel width and freq. parameters are now the same as with AP-B
Still, all other parameters of the wireless are the same on both AP’s apart from the SSID.
We’d pick the AP-B as master since according the spectral scan of the omnitik is has a slightly less noisy environment and it also has more clients (16) associated.
We disable and enable the AP-B, but this time in the NV2 sync setting.
We monitor the log wireless debug file (according same Wiki) to see if the slave tries to sync. And yes the attempt is shown.
We monitor with the interface monitor (/int wi monitor wlan1) on AP-A to see if the sync takes place. Yes, it showing it is in sync with the mac address of the wlan1 of the master.
When we change some parameter in the AP-B-master (download ratio or tdma period size) we see the slave immediately takes same setting.
Conclusion 1)
The sync works and takes place. Good!
But CCQ’s of several CPE’s show lower values or are more fluctuating as before like the connection rates are not as stable as in ‘stand-alone’. Eyebrow is raised.. ![]()
So lets do a bandwidth test from the same clients as before to the same QRT with the same parameters.
BIG disappointment! Maximum we can squeeze out of the tests is 5-8Mbps in download! These units did do almost 50Mbps before!
Spectrum is the same but now all on the AP-B’s frequency.
There is hardly any other traffic from clients around. Less then 4Mbp. aggregated (excluded the speedtest traffic for this test)
Conclusion 2)
The sync is not working in respect of sharing frequency on the same tower. Network speed collapses.
In fact, if both AP’s are working in standalone mode, but on the same frequency I get better speeds than in full sync mode! How is that possible!?!
Other weird event:
On AP-A we have two clients that will not connect to their designated AP when it runs in AP-sync-slave mode.
They will associate when AP-A is in stand-alone mode but same frequency as AP-B (so a loooot of interference) but they will NOT associate the moment the AP goes into slave sync mode!
These two clients are just the same SXT’s lites ‘n’ type as all the others with exactly the same config as all the others (apart from some client depending variable like PPPoE authentication and name.
So why would these two clients not associate to the AP in sync mode where in normal mode they have no issue. Both have signals in the -64 region but I have two others that are actually showing -65 to -66 and they connect fine in both modes…
Conclusion 3)
The sync is not working for all clients units.
Overall conclusion:
Back to the drawboard. I tried several variables that can be changed in the wireless settings. We checked the ‘connect to’ lists and ‘access lists’ over and over again to no avail.
My initial enthusiasms for the nv2 sync has turned 180 degrees in a disappointment..
I was about to cancel my 200 Mimosa client order but I am happy now I didn’t.
I hope Mikrotik finds a solution before we are forced to upgrade more of our P2MP networks. Or does is show again that cheap can’t do the same as expensive?
Is hoping that my present 800 mikrotik clients network could be upgraded to a fully syncd and download ratio configured network for free indeed a free ride on a pink cloud that drops you the moment you wake up?