First Peek At Wi-Fi 6: ASUS RT-AX88U & NETGEAR RAX80

[Sayanux]

For now. Do you have any devices that support it?

nope but netgear rax120 wpa3 support ...

without wpa3 useless now

 

[thiggins]

nope but netgear rax120 wpa3 support ...

That's the router that is only available by invitation...

 

[sfx2000]

The only client I tested in this round was the octoScope Pal, which uses the QCA9984. It had no association problems. I have yet to try the Intel AC9260.

Sounds good - but something to look at with more formal testing - if I recall correctly, SNB did look at this with clients during the early 802.11ac days... and that had a fair amount of value.

 

[RMerlin]

without wpa3 useless now

WPA3 is what's useless now, as there are no clients supporting it yet. Windows 10 1809 doesn't even support it yet (there are hints that support might appear with 1904, or at least they might start to implement support for it).

Nothing prevents manufacturers from adding it to their routers at a later date, when they can actually ensure there are no compatibility issues with the clients that will be available then.

So right now, WPA3 would be nothing more than a checkbox feature for marketing purposes. Like MU-MIMO when it was first announced.

 

[thiggins]

Found the cause of the low uplink throughput on the RAX80. Article has been updated with retest data and explanation.

 

[sfx2000]

Found the cause of the low uplink throughput on the RAX80. Article has been updated with retest data and explanation.

Interesting...

Update 1/14/19: After working with both Broadcom and NETGEAR, I have a better explanation of the low uplink performance. The bottom line is there is a known Broadcom / Qualcomm interoperability issue that is not specific to Broadcom's 11ax chipset. I happened to stumble onto it because of two differences from my normal test method.

....

The low uplink throughput was caused by the STA's packet aggregation becoming stuck at low aggregation when attenuation is high (low signal level) at the end of the downlink run, then not resetting to high aggregation when attenuation is reset to low (high signal level) to start the uplink test.

Reassociating the device between downlink and uplink runs causes packet aggregation to be properly reset.

So if I understand correctly - the QCA client STA's minstrel_ht algo might be a bit borked and not resetting once conditions improved. I'm assuming that the octoscope PAL is using ath9k (maybe with additional hooks for control/debug).

Conversely - my first thought would have been the airtime fairness treatment on the Broadcom side, as this has been problematic in the past with the AP drivers.. if the client STA was in the low bandwith queue, then that would explain why you see good RSSI and Tx rates, but fairness would limit actual air time, and as such, low overall packets per second..

By breaking the current association, this clears the queue, and once the client reassociates, a new queue is established, which resets the mcs and aggregation profile for that device...

Hmmm... probably need to dive into the code and take another look..

Good catch!

 

[thiggins]

@sfx2000: I caught only the symptom. The cause was identified working with both NETGEAR and Broadcom.

The problem is not with airtime fairness. As I described, it's due to packet aggregation not being properly adjusted by the Qualcomm STA.

 

[sfx2000]

I caught only the symptom. The cause was identified working with both NETGEAR and Broadcom.

The problem is not with airtime fairness. As I described, it's due to packet aggregation not being properly adjusted by the Qualcomm STA.

Well... once it's sorted, everyone wins

That you caught it, and in a way that was consistently reproducible - that's why I said good catch.

 

[EmeraldDeer]

The problem is not with airtime fairness. As I described, it's due to packet aggregation not being properly adjusted by the Qualcomm STA.

Let's say the Wifi STA is my phone. If I walk away, the packet aggregation will adjust to low. But if I walk back toward the router's AP, it will not readjust to high on it's own? I would need to disconnect and reconnect? Qualcomm is still refining 802.11ac and 802.11n?

 

[thiggins]

Let's say the Wifi STA is my phone. If I walk away, the packet aggregation will adjust to low. But if I walk back toward the router's AP, it will not readjust to high on it's own? I would need to disconnect and reconnect? Qualcomm is still refining 802.11ac and 802.11n?

It's highly unlikely you would see this problem in open air conditions. The short distance in the chamber between AP and STA antennas makes the problem more likely to happen when AP and STA antennas are not positioned to maximize spatial diversity.

That's why my normal process rotates the AP under test while traffic is running.

 

[sfx2000]

The problem is not with airtime fairness. As I described, it's due to packet aggregation not being properly adjusted by the Qualcomm STA.

After looking at code - I respectfully disagree - the ath9k code looks fine here - the AP drives the bus for things, not the client STA... ath5k and ath10k are similar here...

One can look at the QC-Atheros client STA by directly by mounting the debugfs in linux and look at stats there.

If it were a Client STA issue, we'd see thing with Realtek, Marvell, MediaTek, etc as AP's

It's likely a Broadcom bug - which makes sense, since Broadcom folks made the fix (this is low level, so Netgear probably won't touch that layer as this is entirely within the MAC layer on WiFi)

 

[Dave in NM]

So one difference i see is RAX80 says 8 streams, and AX88U only 4? Is that correct?

 

[thiggins]

So one difference i see is RAX80 says 8 streams, and AX88U only 4? Is that correct?

That is just marketing games. NETGEAR is counting 4 streams for the 5 GHz radio and 4 for 2.4 GHz. Same as the ASUS. They are built on the same Broadcom chipset platform.

 

[Dave in NM]

That is just marketing games. NETGEAR is counting 4 streams for the 5 GHz radio and 4 for 2.4 GHz. Same as the ASUS. They are built on the same Broadcom chipset platform.

That's good to know, so these are relatively the same then.

 

[coolbeans2016]

Flash forward to January 2020, especially with Asus's latest firmware release for the RT-AX88U & Merlin's improvements it is THE ONLY WiFi6 router available the has "NO-BUG" hassle-free WAN aggregation!!!
I went through both of Asus's newer routers & Netgears & all 4 will fall to 25mbps within 24 hours of setting WAN aggregation & no solution in sight.
Asus scored big time with this AX6000 in my opinion!!!