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RobCo
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Mikrotik WLAN & CAPsMAN - Spatial stream perfomance issue

Thu Feb 21, 2019 9:50 pm

The problem is - and I don't really have any idea what causes it - wireless speed is cut roughly by HALF from what it is supposed to be.
The picture is:
NAS -gigabit> Mikrotik CSS326 -gigabit+PoE> wAP AC -wireless conn 802.11ac 2x2> PC with realtek 8822BE wireless module.
RB3011 is connected to CSS326.

The issue itself? For example, I'm trying to download from NAS a movie - a whole videofile, MKV packed, 30GB size. But instead of 60 MB/s, I have only 30MB/s. And I really don't know what causing the issue - and that drives me mad. Moreover, connection itself is super-stable - it just looks like something caps it at 30-40MB/s.

Next things I've tried:
1) Wired connection gives me ~900 Mbps. So switch is out of question, as well as maybe RB3011.
2) wAPs powered by PoE - cable cat 5e, 8 wires/4pairs. Everything is in working condition.
3) Aside of 8822BE, I've tried killer chipset and Intel AC-9560 - all the same, it just stucks at 25-40 MB/s.
4) Also tried making simulatenous workload for wAP, by downloading the same file on two devices (Killer and Realtek, Intel and Realtek) - speed just divided by half, giving 15-16 MB/s for each device.
5) Local storages are non-issue here - NAS works with two SATAIII HDDs, united in RAID0. Both client devices have NVMe drives with 3GB/s sequential write.
6) As well as it's non computing issue - NAS CPU is barely loaded, not even mentioning the PC's.

All in all, here's the screenshot - I guess, it would help to make thing even more clear, than I could writing all the stuff down....



UPDATE: So far, it seems to be MIMO issue - either it is CAPsMAN configuration or usual AP setup - doesn't matter, MIMO doesnt work and Tx/Rx goes through 1 spatial stream, thus cutting speeds to 1 channel: 433 mbps for 802.11ac and 150 mbps for 802.11n.


And here's my expectations, or should I say, just "wish" - Intel 9560 + UBNT AC-SHD
http://piccy.info/view3/13040178/113032 ... 10364e022/
Last edited by RobCo on Sun May 12, 2019 8:14 am, edited 5 times in total.
 
whatever
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Re: CAPsMAN poor wireless speed

Mon Feb 25, 2019 6:36 pm

How do you decide how fast your wireless speed is supposed to be?

My hap ac2 802.11ac 2x2 speed with capsman and local forwarding is indeed about half of what you would expect from the standard under perfect conditions, until now I've been blaming it on cheap hardware and poor drivers. But considering the various routeros wifi bugs, which have been fixed in the past months, I wouldn't be surprised if that difference between theoretical and practical speed was really caused by some hidden bug. As long as there is no fix we will never know :)
 
RobCo
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Re: CAPsMAN poor wireless speed

Wed Mar 06, 2019 12:47 am

I suggest my speed from these factors:

1) Both Tx and Rx have 2 chains working simultaneously in 2 streams - thus making 866 mbps real. wAP AC and Realtek 8822BE - you can find specs for both. 2x2:2, what can go wrong?
2) Since mikrotik admit their wireless protocols far from ideal, thus output is around 50-65% - it makes 500 mbps real.
3) All wired conncetion rated at 1 Gbps.
4) I've made channel reconnaissance and setup, so no overlapping channels, NOT EVEN CLOSE.
5) Registration table reports, device is connected at 866 Mbps rate, with 2 streams up and perfect signal strenght : -30-40 dBm.

So, I think there's no doubts left that download speed MUST be at least arount 60 MB/s. It better be 100 MB/s really, since 802.11ac states 866mbps for 2x2:2 configuration, and I have nearly ideal/perfect conditions, so I don't really get why mikrotik can't provide at least 90% of full 802.11ac potential. :?
 
zeusca
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Re: CAPsMAN poor wireless speed

Wed Mar 06, 2019 6:32 pm

Have you tried local forwarding vs capsman forwarding to see if there's a difference?
 
RobCo
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Re: CAPsMAN poor wireless speed

Fri Mar 08, 2019 2:49 pm

Have you tried local forwarding vs capsman forwarding to see if there's a difference?
Of course I did - and the matter of fact - I ALWAYS use local forwarding enabled, cause capsman forwarding gives me like 10% of wireless perfomance.

I've tried disabling other CAPs, both 2.4 and 5, I've tried removing all the clients from tested CAP - no use, nothing helped.
 
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Re: CAPsMAN poor wireless speed

Fri Mar 08, 2019 4:16 pm

Personally, I get > 100Mbps using wAP AC + RB3011 running CAPsMAN, local forwarding.

How crowded is the wireless around your place?
Are APs locked to CAPsMAN and using encryption?
 
DSK
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Re: CAPsMAN poor wireless speed

Fri Mar 08, 2019 7:46 pm

Could you post a screenshot of winbox CAPSMAN-Channels?
 
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Re: CAPsMAN poor wireless speed

Fri Mar 08, 2019 10:45 pm

Personally, I get > 100Mbps using wAP AC + RB3011 running CAPsMAN, local forwarding.
But you shouldn't you expect > 500Mbps with three chains on 5GHz ac? I consider 100Mbps with that hardware pretty slow, that speed is already achievable with 2.4GHz dual chain n.
 
RobCo
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Re: CAPsMAN poor wireless speed

Wed Mar 13, 2019 12:42 pm

Personally, I get > 100Mbps using wAP AC + RB3011 running CAPsMAN, local forwarding.

How crowded is the wireless around your place?
Are APs locked to CAPsMAN and using encryption?
I live in suburban area, big house, closest neighbout is literally ~100m away. Not corwded at all - area is "crowded" by only me, myself and I.
No encryption, and no, CAPs don't locked on CAPsMAN - does it positively affect the perfomance?
Could you post a screenshot of winbox CAPSMAN-Channels?
MAIN2.png
But you shouldn't you expect > 500Mbps with three chains on 5GHz ac? I consider 100Mbps with that hardware pretty slow, that speed is already achievable with 2.4GHz dual chain n.
That's what I'm talking about - and I've metnioned it already (no?) - that using dual-chain 2.4Ghz band with 802.11n protocol, I can't even beat through Internet channel! 100mbps are being choked by poor wireless perfomance. I mean, I'm experiencing overall wifi perfomance drop, not only PC and 5Ghz 802.11ac connection.


And the most desperate thing about all this - I've tired reseting all the stuff, leaving onyl default configuration by mikrotik, and making fast provisioning for caps, just ot ensure it's not my fault by too overcomplicated settings - aaaand all the same, 300 mbps cap in 802.11ac5GHz, and 50-70 mbps cap in 802.11n2.4Ghz .
5 MB/s by air with 802.11n 2stream is waaay to bad.
 
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Re: CAPsMAN poor wireless speed

Wed Mar 13, 2019 1:10 pm

Looking at your first screen shot in your first post, I'd say that's a decent connection.
You're connected at VHT MCS 7 with two spatial streams and short guard interval resulting in 650MBps connection rate at 80MHz.
Keeping in mind that actual real-life throughput is roughly 50...65% of the w/l connected rate, you're in a pretty good shape.
Increasing throughput further from here from here would ideally be a different wireless client supporting three spatial streams which would give you 975MBps @ VHT MCS 7, resulting in roughly 500...650 MBps real-life throughput.

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DSK
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Re: CAPsMAN poor wireless speed

Wed Mar 13, 2019 1:28 pm

Could you post a screenshot of winbox CAPSMAN-Channels?
MAIN2.png

CAPsMAN-Channel. Control Channel under CAPsMAN is what I need to see it should be in auto mode.
 
RobCo
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Re: CAPsMAN poor wireless speed

Wed Mar 13, 2019 1:33 pm

Looking at your first screen shot in your first post, I'd say that's a decent connection.
You're connected at VHT MCS 7 with two spatial streams and short guard interval resulting in 650MBps connection rate at 80MHz.
Keeping in mind that actual real-life throughput is roughly 50...65% of the w/l connected rate, you're in a pretty good shape.
Increasing throughput further from here from here would ideally be a different wireless client supporting three spatial streams which would give you 975MBps @ VHT MCS 7, resulting in roughly 500...650 MBps real-life throughput.

-Chris
When I lived in the city, I've used to have 1Gbps internet channel. Though, it was roughly 1 Gbps - more like 900 mbps at night (best), and down to 600-700 mbps daily. And asus RT-AC66U as a router - no complicated wifi stuff, just a a swetpot with 3 antennas.
I've had 450 mbps on my current iPhone 6S result in speedtest, in 5Ghz ac band. I don't know if it has 1S or 2S - and I remember that device is 1st wave ac, so 2x2:2 40Mhz at best.
So I don't feel THIS like "pretty good" at all.
Could you post a screenshot of winbox CAPSMAN-Channels?
MAIN2.png

CAPsMAN-Channel. Control Channel under CAPsMAN is what I need to see it should be in auto mode.
What, do you mean frequency? No way, it gonna throw overlapping ones in.
Or channel width? But is there any difference between I manually set 20MHz + Ceee, or I just disable that tab, leaving Ceee?
 
RobCo
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Re: CAPsMAN poor wireless speed

Mon Mar 25, 2019 7:21 pm

Ok, so I've checked streams, leaving 1 stream per test phase - so far, I've managed to discover it IS streams issue.
Thus, when leaving only 1 chain activated and 1 stream flow, I get the same 30 MB/s - 270mbps. So wireless perfomance is stucked at this point no matter what - whether I turn on all chains available (and possible), leaving 3, or 2, or 1 - it looks like it always works within 1 stream. And that's a real issue.

I'm 99% confident it's mikrotik's side flaw - for that matter, I found PCE-AC68 adapter for a good price, so I'll be able to write down my final verdict soon - but that's how it is for now.
 
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Re: CAPsMAN poor wireless speed

Thu Mar 28, 2019 12:47 am

Aaannd....what needed to be prooved. I've just received my AC68 unit, plug-it in, up-to-date drivers, of course - and I get the SAME goddamn speeds. With 3 streams up now....

P.S. And don't tell me that's ok (if you read this at all, mikrotik support), that it's only "50%" etc, etc...
 
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Re: CAPsMAN poor wireless speed

Thu Mar 28, 2019 10:03 am

So MIMO is broken in some way that prevent any speed gain from additional chains? Interesting observation, let's hope that this is reproducible and fixable by mikrotik.
 
RobCo
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Re: CAPsMAN poor wireless speed

Thu Mar 28, 2019 12:31 pm

So MIMO is broken in some way that prevent any speed gain from additional chains? Interesting observation, let's hope that this is reproducible and fixable by mikrotik.
Yeah, seems like it. Furthermore, as I mentioned before (here or in support ticket?), MIMO seems to be broken broad - "at all" - if I can say so - because I really can't imagine how it can be broken.
Both, with CAPsMAN involved and without it, in regular AP mode, 2.4GHz or 5 GHz band, 802.11 ac or n or b - doesn't matter, MIMO doesnt work.

It's even more confusing that I was unable to restore previous state of things even downgrading down to 6.38 versions - does it mean it's low-level hardware related?
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Mon Apr 01, 2019 9:26 pm

So, anyone? 6.45beta, still all the same - can't be only me experiencing this stuff. Or can I?
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Tue Apr 02, 2019 10:12 pm

Hi RobCo,

I really feel your pain, I do.

Although I'm not convinced my post will help you, it may spark some insight in you.

1st thing - are you sure your clients are actually WIRED with 2 separate antennae?

2nd thing - for MIMO to work well one needs a good spatial separation for all spatial streams, i.e. there should be no correlation between the 2 spatial streams. This is hard to achieve with ordinary antennae and LoS between AP and client.

You could also try iw phy from most Linux boxes to check if your client WiFi cards support MIMO.On Windows you can try netsh wlan show wirelesscapabilities from admin CMD.
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Wed Apr 03, 2019 12:48 pm

Hi RobCo,

I really feel your pain, I do.

Although I'm not convinced my post will help you, it may spark some insight in you.

1st thing - are you sure your clients are actually WIRED with 2 separate antennae?

2nd thing - for MIMO to work well one needs a good spatial separation for all spatial streams, i.e. there should be no correlation between the 2 spatial streams. This is hard to achieve with ordinary antennae and LoS between AP and client.

You could also try iw phy from most Linux boxes to check if your client WiFi cards support MIMO.On Windows you can try netsh wlan show wirelesscapabilities from admin CMD.
yeah, np mate, any idea is good!
Though I'm not a guru, and really have no idea at this moment whether it's hardware has it's flaws and works worse despite all specs available for public, or.... it's just me.
Anyway, I can only relate to software I have - so, as you can get it, you can't trust it 100% -> can't be sure 100%.

1st, Physically, all chains are active, all antennas wired. The reality is - I don't know for sure :D
What I see in registration table (screenshot attached), it sees 3 spatial streams though it's really doubtfull info, suggesting from rates it shows and the real world throughput I get
client.png
Regarding the cmd promt - even within administrative mode, it shows almost nothing usefull:
For AC68 usefull info is missing at all - either "value not available" or "not supported", even if it IS and I know it. But still, no info regarding "number of antennas", "max number of channels, simultaneously", no info about regular MIMO at all, etc.

For 8822BE, a little bit more, but still not enough - no info regarding antennas, channels aswell - but at least it shows it does support MU-MIMO (no info regarding MIMO), number of Tx Spatial Streams = 2, Rx spatial streams = 2, concurrent channels = 1.

Regarding 2nd - really no idea about the built quality or engineering idea behind all of this mate - and I don't know any mean way to tweak these for wireless clients.
LoS is....well, ATM of testings, it's around 2-3m. No obstacles, no metal construction.
I've tried stepping off a little, 10-15m, a thick brick wall 15cm in-between - but no improvements. Moreover, I have feeling like the signal itself is great, it holds those 300mbps and 50mbps really good - for a wireless solution, almost like a wire.
Dunno, maybe I want too much - though the things I want from this hardware are not stellar. And also I've decided to check bandwith with iperf so people would get something more understandable, than messy "I download a movie from NAS"
So here it is: AC68
AC68.png
8822BE
8822BE.png
Strange, isn't it? I mean, 1st - no difference between 2x2:2 and 3x3:3 client? I know Realtek chipset is much newer than asus - but asus is way more powerfull device. 2nd - well you can say that 5GHz perfomance is good, but shouldn't it be much better with 3x3? Like, let's say 800ns AC1170/2 = 585 mbps at least? Damn, I agree for 500, but 300? And what about 2.4GHz?
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Wed Apr 03, 2019 9:27 pm

Yes, you're totally running @ 1 spatial stream, i.e. 1 chain.

Also, you're not wanting too much of your HW, you're just wanting what you paid for, which according to MT's own page is 1300 (or 900Mbps if you consider the real life). What you get is a far cry from the advertised speeds...

Check this out - https://www.cisco.com/c/dam/en/us/produ ... c383047840

According to the link from this renowned manufacturer of networking equipment above, you're not even getting 256QAM! 256QAM should yield ~433MMbps.

Honestly, I don't know what else to suggest for troubleshooting. Had we some fancy test equipment things would have been easy. Maybe if you can temporary get another wAP for testing, you could try setting up a WiFi network between those 2, and see how they play it out?
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Wed Apr 03, 2019 9:51 pm

Yes, you're totally running @ 1 spatial stream, i.e. 1 chain.

Also, you're not wanting too much of your HW, you're just wanting what you paid for, which according to MT's own page is 1300 (or 900Mbps if you consider the real life). What you get is a far cry from the advertised speeds...

Check this out - https://www.cisco.com/c/dam/en/us/produ ... c383047840

According to the link from this renowned manufacturer of networking equipment above, you're not even getting 256QAM! 256QAM should yield ~433MMbps.

Honestly, I don't know what else to suggest for troubleshooting. Had we some fancy test equipment things would have been easy. Maybe if you can temporary get another wAP for testing, you could try setting up a WiFi network between those 2, and see how they play it out?
Yup, that's what I'm talking about.
Already have 3 - I'll think it out, just always lack of time. Wish things just always would work as intended (wanted)
 
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zlobster
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Wed Apr 03, 2019 10:08 pm

Wish things just always would work as intended (wanted)
Wish things just always would work as advertised. FTFY

When you went to the store, did the seller tell you "I'll charge you either $15 or $89, depending on whether it runs fine or not"? Nope, he didn't. He wanted a hefty amount of your hard earned cash no matter how the product performs.

As for the test, here is what I suggest:
- connect one wAP to some PC;
- connect another wAP on to some other PC;
- get rid of all other 5GHz airwave polluters;
- set one of the wAP as PTP Bridge AP;
- set the other one as PTP Bridge CPE;
- make sure you have a good 5-10 meters between them;
- run iperf3 between the 2 PC, which are behind your newly set PTP Bridge;

I'm by no means a MT expert, so there may be a more lean and appropriate way to do this, but we both depend on someone else to guide us.
 
RobCo
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Thu Apr 04, 2019 11:24 pm

Well, it's not rate issue or MIMO issue - Viesturs reminded me about multi-stream option in iperf - at least benchmark gives out 500mbps when using 3 or more streams.
2.png
Max result was somthing about 500-530 mbps.
On the other hand, I've managed - with a little tweaks - rise rates up to MCS9-80Mhz figures. Unfortunately, 0 impact on a real bandwith.
1.png
Additionally, I've swapped "server" and "client" - so server became a PC connected wirelessly, and client became a laptop with Gbps wired connection - and perfomance was capped at 350 mbps even with 3-5-10-15 streams at the same time.

And, as always, IRL speed when downloading/uploading smth between real clients is always around 300-350 mbps.

So, basically its not MIMO fault or anything - it's just "poor" perfomance. I mean, anybody can call me nuts calling 350mbps "poor", but as zlobster said - I've paid for some real outstanding perfomance, and I have some hardware to get at least 50% of it.
That's what you say about WiFi, right? "Divide it by two - and You get IRL perfomance" ?
So, I'm not getting it in AC band. Unfortunately.
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Sat Apr 06, 2019 3:43 pm

The wAP AC CPU is likely maxing out at that bandwidth.
 
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zlobster
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Sat Apr 06, 2019 8:31 pm

Getting ~500Mbps with multi-stream iperf3 means all WiFi technologies are kicking in, i.e. they are working.

What R1CH says may be the truth, sadly... Can you start profiling on the wAP AC and see how much the CPU gets loaded during iperf?
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Mon Apr 29, 2019 3:34 pm

The wAP AC CPU is likely maxing out at that bandwidth.
Getting ~500Mbps with multi-stream iperf3 means all WiFi technologies are kicking in, i.e. they are working.

What R1CH says may be the truth, sadly... Can you start profiling on the wAP AC and see how much the CPU gets loaded during iperf?
Hey guys, sorry for the delay.

Yeah, regarding your question - and it's kinda odd really - AT this moment, CPU at wAPs loaded roughly at 40-60% mark, with temp being around 62-68C, so no throttling either. BUT!, it local forwarding mode enabled. With CAPsMAN forwarding, with totally the same load applied, wAPs go insane 80-90% load, wireless speed drop a little too. I can't really understand it, since, shouldn't it be other way round?

But yeah, while getting highest speed, CPU load barely hits 70%, mostly 40-60%.


Another thing for the past month - I made some tweaks with CAPsMAN wireless and Rates configuration:
got rid of slow 802.11a/b basic rates, I've decided to leave indusrty reliable >12mb, plus some Hw. and preamble tweaks,
and I've got this:
123.png
And seems like without any other device or distance loss.

But I still don't like it - spatial stream tech is not working at full capacity ATM, not even close. I DO know about cointerference, that I won't get that much efficieny as I get with 1, free of any obstacle antenna. But still I hoped for something like 50% per each stream, when using 2 or 3 SS client.
So far, I've observed SS perfomance - with 1 chain I get 30MB/s (250-260Mbps) easily.
With 2 chains, as you see screenshot - 1.5x improvement, almost 50 MB/s (420-460 mbps), which is good. I mean, it's not 60MB/s that I can see within other AC network, but still.
Still get 0 improvement with 3 spatial streams, 3 chains working between wAP AC client and Asus AC68 unit. And I don't really get why is it so bad - while testing, I'm sure I have only and only 1 client sitting at 5GHz/AC band, not only within tested wAP access point, but within whole wireless network!
This is what I get with AC68
1234.png
Top speed is a liiiiiitle bit higher - rare ~52MB/s to 50MB/s, vs 48-50MB/s with Realtek 8822BE. But drops with AC adapter are more significant - while I get stable connection with realtek, AC68 gives me time-to-time drops up to 2x-3x times - though, they are rare and perfomance is quickly re-established.


So many questions....
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Mon Apr 29, 2019 9:20 pm

... it local forwarding mode enabled. With CAPsMAN forwarding, with totally the same load applied, wAPs go insane 80-90% load, wireless speed drop a little too. I can't really understand it, since, shouldn't it be other way round?
If local forwarding, wAP's CPU only needs to copy packets from wireless interface (which alone is a CPU-intensive operation on RBs) to ethernet interface. Gateway (for simplicity's sake let's say it's CAPsMAN device) takes those packets off ethernet and routes them to WAN.
And everything in reverse order for packets from WAN towards wireless client.

If CAPsMAN forwarding, wAP's CPU needs to get packets from wireless interface (which alone is a CPU-intensive operation on RBs), encrypt them into a CAPsMAN tunnel (a pretty CPU-intensive operation) and push them to ethernet interface. Then CAPsMAN device fetches them from ethernet interface, decrypts them from CAPsMAN tunnel (CPU-intensive operation as well, usually slightly less than encryption though) and routes them to WAN.
And everything in reverse order for packets from WAN towards wireless client.

Do you still think that CAPsMAN forwarding should perform better (with lower CPU load) than local forwarding?
BR,
Metod
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Mon Apr 29, 2019 9:38 pm

Still get 0 improvement with 3 spatial streams, 3 chains working between wAP AC client and Asus AC68 unit.
To have MIMO (multiple spatial streams) working, those streams have to be well separated (radio-wise) from each other. A great separation technique is use of two orthogonal polarizations (if usual stick-shaped antennae are used it means having them oriented at angle of 90° between them ... but that only works for a pair of antennae). A good technique is to have antennae separated spatially ... by at least a few wavelengths. Wavelength at 2.4GHz is around 12.5 cm, so those antennae should be at least 30 cm (a foot) apart (this is a bare minimum, more than half a metre would be better). It is easier to get enough spatial separation at higher frequencies, hence higher number of spatial streams on 5.xGHz band (wavelength of less than 6 cm, hence same 30 cm separation is pretty good).

And that must be done on both ends of a radio link ... or else things don't work as (naively) expected.
BR,
Metod
 
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Re: Mikrotik wireless LAN - WiFi - MIMO not working

Mon Apr 29, 2019 11:19 pm

Still get 0 improvement with 3 spatial streams, 3 chains working between wAP AC client and Asus AC68 unit.
To have MIMO (multiple spatial streams) working, those streams have to be well separated (radio-wise) from each other. A great separation technique is use of two orthogonal polarizations (if usual stick-shaped antennae are used it means having them oriented at angle of 90° between them ... but that only works for a pair of antennae). A good technique is to have antennae separated spatially ... by at least a few wavelengths. Wavelength at 2.4GHz is around 12.5 cm, so those antennae should be at least 30 cm (a foot) apart (this is a bare minimum, more than half a metre would be better). It is easier to get enough spatial separation at higher frequencies, hence higher number of spatial streams on 5.xGHz band (wavelength of less than 6 cm, hence same 30 cm separation is pretty good).

And that must be done on both ends of a radio link ... or else things don't work as (naively) expected.
Well.... you know, this stuff relates to my problem as bad as it can be at all
Last edited by RobCo on Sun May 12, 2019 8:13 am, edited 2 times in total.
 
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Re: Mikrotik WLAN & CAPsMAN - Spatial stream perfomance issue

Sat May 11, 2019 11:46 pm

I guess, it's just poor wireless support from MT and CPU limitations - things I somewhat forget and kept knocking wall with my head. Oh well.
 
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Re: Mikrotik WLAN & CAPsMAN - Spatial stream perfomance issue

Wed May 15, 2019 5:33 am

The 40-60% processor load in your wAP ac is an average. Due to latency at various internal points (wireless microprocessor, kernel scheduler, hardware interrupts), the wAP ac processor is a limiting factor here. As the MIPSBE SoC is older and cost-optimised, some of the internal datapaths may be a bit limited too.

You'd be in much better position with an (overkill) RB4011 WiFi and RouterOS 6.45, which enables all four chains correctly. I really wish Mikrotik had a dual-core >1GHz processor ARM AP with spatially-diverse 3-chain 5GHz and 2-chain 2.4GHz radios.

Finally, I suggest measuring WiFi throughput with iperf UDP, so you can decouple TCP congestion control.
 
r00t
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Re: Mikrotik WLAN & CAPsMAN - Spatial stream perfomance issue

Wed May 15, 2019 4:49 pm

You'd be in much better position with an (overkill) RB4011 WiFi and RouterOS 6.45, which enables all four chains correctly.
RB4011 have it's own set of quirks and issues, 5GHz WIFI is very much broken as you can see here: RB4011: wlan1 disabling itself
 
RobCo
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Re: Mikrotik WLAN & CAPsMAN - Spatial stream perfomance issue

Sat May 18, 2019 3:41 pm

Due to latency at various internal points (wireless microprocessor, kernel scheduler, hardware interrupts), the wAP ac processor is a limiting factor here. As the MIPSBE SoC is older and cost-optimised, some of the internal datapaths may be a bit limited too.

You'd be in much better position with an (overkill) RB4011 WiFi and RouterOS 6.45, which enables all four chains correctly. I really wish Mikrotik had a dual-core >1GHz processor ARM AP with spatially-diverse 3-chain 5GHz and 2-chain 2.4GHz radios.

Finally, I suggest measuring WiFi throughput with iperf UDP, so you can decouple TCP congestion control.
That's exactly what my point is - though, cAP AC has just the same exact drawback, while having ARM chip - though, it seems like arm counterpart for cAP is just the same cheap stuff as qualcomm's one.
Still, I think MK could do better on optimizing real bandwith up to 500 mbps levels, for 2x2:2 client. MU-MIMO on the other hand would somewhat skulk bandwith problems, but that's just offtop lyrics...

RB4011 is not an option for me TOTALLY - first, I need mesh network due to home size and sq2; second, I have PPPoE IPS connection through fiber+GPON, and it's the only option for me ATM, so I'm hardly going to buy RB4011 - besides, it's too bulky to use as on-wall AP

And UDP test shows 1 Mbit, lol

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