Mesh performance with various routers

Installing and Using OpenWrt Network and Wireless Configuration
1

Hi.
I'm using two Netgear r6220 and a x64 based (compex WLE600VX wifi, ath10k driver). 21.02 RC4 and wpad-wolff package for each router.

I have tested various mesh possibilites between these devices (two at each try).

  • on 5GHz AC band, it reaches 650 to 867 Mbit/s speed (80 MHz width; link speed depending on distance). That is the best expected from the hardware.
  • on 2.4 GHz N band, it only reaches 144 Mbit/s (20 MHz width). Hardware should be able to reach 300 Mbit/s with a 40MHz width. I have also tried the "force 40MHz".

So, is there a limitation or a trick I'm not aware of, preventing link speed over 144Mbit/s on 2.4 GHz N band ?

2

Hello @badulesia

I don't have a R6220 (MT7621) but I have noticed similar behavior with AR750S and EA8300 operating in 802.11s on 19.07.7. Both devices are 2x2:2 on 2.4Ghz like the R6220.

  • All nodes are AR750S

  • The AR750S (QCA9563) will not operate a mesh at 300Mbps / HT40 / 2.4Ghz despite commanding it to do so from LuCI. But the mesh remains operational and runs at a reported speed of 130Mbps.

  • I typically get around 50-65Mbps max throughput on 2.4Ghz / HT20 / MESH STA

  • Turning the mesh off and broadcasting an AP in 300Mbps / HT40 / WPA3 /2.4Ghz works.

  • All nodes are EA8300

  • The EA8300 (IPQ4019) is set to run at HT20 on 2.4Ghz but using a WiFi tool it is advertising a network speed of 195Mbps (contrary to LuCI-->status-->overview-->144.4Mbits max). Selecting HT40 didn't change the reported speed. Forcing 40Mhz caused it to lose the mesh.

  • Turning the mesh off and broadcasting an AP in 300Mbps / HT40 / WPA3 / 2.4Ghz works.

The best I can figure is that 802.11s introduces overhead which would eat into the available bandwidth and CPU budget and that appears to be what I am seeing with these 2 devices. Or it could be wifi driver related. Or I could be totally wrong. Thanks for sharing though as I am interested in that device for mesh networking and was looking at it recently.

  • Since the R6220 is a 128/128MB device you could try wpad-mesh-openssl?

  • Check the guard interval?

Update:

I am not confident in my WiFi scanner tools accurately reporting on 802.11s link speed. I don't use wireshark yet. Sticking with OpenWRT's status-->overview until I get better tools.

3

Hello.
So this behavior is probably normal.

Here is the full story.
The goal is to improve a secondary home network. Actually I'm using a R6220 as main router, and a very old 3700v2 and mesh AP. Link is in the 2.4 GHz band, as the mesh AP doesn't provide 5GHz AC. I get only 130 Mbit/s, but this is the maximum of the 3700v2.

I'm planning to use the R6220 as mesh AP, and buy a EA8300 as new main router : mesh link will be in 5GHz AC. So I have performed various tests with extra devices (another R6220 and a x64) to simulate this, and the result is good.
And ... I have also performed tests in the 2.4GHz band just to see what can be obtained (more than 130Mbit/s ?), and find this issue.

Thank you.

4

I would be interested to know if that works.

Test 1:

I just iperf3 tested 2 nodes on a AR750S mesh @2.4Ghz / HT40 / Force 40MHz mode:

300Mbps test:

iperf3 -u -c 123.123.123.123 -t 60 -b 300M

[ ID] Interval            Transfer        Bitrate      Jitter      Lost/Total Datagrams
[  5]   0.00-60.00  sec  2.10 GBytes   300 Mbits/sec  0.000 ms  0/1553852 (0%)  sender
[  5]   0.00-60.02  sec   416 MBytes  58.1 Mbits/sec  0.171 ms  1249716/1550827 (81%)  receiver

....and the iperf3 server node showed occasional 270-300Mbps on LuCI-->status-->overview. I had to screen shot it because I couldn't believe it.

Screenshot 2021-08-22 at 11-09-41 GL-AR750S - Wireless - LuCI

...but the iperf3 client node never went higher than 144.4Mbps.

Test 2:

Both nodes set to 802.11N / 20HT only

300Mbps test: Reverse nodes

iperf3 -u -c 123.123.123.123 -t 60 -b 300M -R

   
[ ID]   Interval           Transfer         Bitrate     Jitter     Lost/Total Datagrams
[  5]   0.00-60.00  sec  2.10 GBytes   300 Mbits/sec  0.000 ms  0/1553957 (0%)  sender
[  5]   0.00-60.00  sec   405 MBytes  56.7 Mbits/sec  0.167 ms  1258167/1551657 (81%)  receiver

...now the other node is reporting occasional connections at 243-300Mbps - but it can't sustain it. This is with the Gl-Inet factory f/w 3.201 (default drivers: kmod-ath9k-common and kmod-ath9k drivers for 2.4Ghz).

It is a busy spectrum in my location.

5

The compex wifi card (in the x64) is a close model than of the EA8300. So I assume the result with a real EA8300 should be good too.

Thanks for sharing though as I am interested in that device for mesh networking and was looking at it recently.

I assume you were talking about the R6220 ? Well it's a good device and it performs well. I have two, one as a main router, and one as an AP in another network. If you can find a second hand one at a cheap price it's worthy. Nevetheless you can find similar hardware in various new models (cudy, newifi) at a very cheap price. So don't focus necessarly on a R6220.

6

That's good it worked as it doesn't always with different chipsets or antenna diversity / mu-mimo. All your devices are 2x2:2 mu-mimo so thats good.

I like the R6220 over the Newifi 2/3 because it seems better supported / reliable and inexpensive compared to C7 or EA8300. I can get them here for around $30 used which is half the cost of a C7. Plus they have U.Fl connectors internally. I haven't looked at Cudy yet.

Thanks!

7

I must confess that I like a feature on the Netgear router: the nmrpflash utility that allows to upload the stock firmware in case of trouble. Other brands have TFTP solutions too, but I know how to use nmrpflash. It saves my a.. a couple of times. I only had trouble with the R6220 while trying some master snapshots. They are not certified to work, so nothing to blame. Every releases work fine. If you can have one for $30, well go on.

8

I should pay attention to this before choosing a new device. Thanks.
The EA8300 has two AC 867Mbits 2x2, so it seems a reasonable choice. I don't need more.

9

Hope it works but even if the EA8300 doesn't mesh with the other devices it's still a great AP to attach to a mesh. I kind of wish I went that route ie. make a mesh with the cheapest / best device (R6220 5Ghz/866Mbps) and then attach AP's. Hindsight always 20/20.

10

I got news ! I have checked this document, and than changed the channel from 4 to 7. I can now have a much higher link (HT40), reaching 250 to 300 Mbit/s.

11

In a faraday cage?

12

lol.
Iperf3 tests reach 72 Mbit/s, that better than previously. The neighborhood is very noisy, lots of routers, some with their own channel, many overlapping, a real mess. Previously I was using channel 4 because it was the most quiet.
Thanks for the idea, it solved the issue.

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