2.4 ghz slowdown

[vit5421]

Dear Yuhhaurlin, I have a problem with 2.4 ghz on the latest DD-wrt build (r32149, 05.27.17). Sometimes when my clients (windows, androids) little bit far form router the connection is stuck and i have around 1-5 mbs download speed for all my clients. The signal strength is around 50dbm and connection speed is still 144 mbs. The upload for my clients works fine as usual all the time. I even try to restart the router and nothing change until i am close to router. The wrt1200 and 1900 works fine in the exact same location and exact same settings. The wifi status is still not available and i cant see the real router negotiation speed for Tx rate but i guess that something is wrong there at the driver side

[yuhhaurlin]

Cat you make sure that you test the latest version of code?

[vit5421]

I guess it was includes in Brainslayer latest build

[yuhhaurlin]

Can you cat /sys/kernel/debug/ieee80211/phy0/mwlwifi/info?

[vit5421]

driver name: mwlwifi chip type: 88W8964 hw version: 7 driver version: 10.3.4.0-20170512 firmware version: 0x09030007 power table loaded from dts: no firmware region code: 0x10 mac address: 60:38:e0:b2:5e:92 2g: enable 5g: enable antenna: 4 4 irq number: 45 ap macid support: 0000ffff sta macid support: 00010000 macid used: 00000001 radio: enable iobase0: e0b80000 iobase1: e0e00000 tx limit: 1024 rx limit: 16384

[yuhhaurlin]

Did you encounter the same problem if you run stock firmware?

[vit5421]

I newer try stock firmware but i have the same problems on 2 wrt3200

[yuhhaurlin]

What did you mean?

[BrainSlayer]

i add here some forum reports. one user in my forum complaints that slowdowns are happening after 7 - 8 hours of testing. another has problems with tx only performance. so downstream is full speed, but upstream is slow. but this effect is only present in 2.4 ghz. i'm still trying to find out his client chipset for investigation

[yuhhaurlin]

Only happened for 2.4g band?

[BrainSlayer]

yes. only in 2.4 ghz band people are seeing such issues like slowdowns. the user reported its on tx only. he tested with a samsung galaxy s8 and a s8+ and with a intel client. and is operating in pure 802.11n mode . this user says the issue is present immediatly without waiting

[yuhhaurlin]

Does the stock firmware have the same problem?

[BrainSlayer]

i dont know. never used stock nor do i have informations about it. so this report is only related to mwlwifi so far

[ghost]

I can confirm a 2.4ghz slow down issue with the wrt3200acm, also affects stock. 5Ghz performance presently is rock solid on this driver, however DFS is broken. (Using lede 17.01.1 r3316-7eb58cf109 with latest mwlwifi driver).

[yuhhaurlin]

What do you mean DFS is broken? I and our QA can test channel 36 with 160 Mhz. If DFS is broken, there is not way for this kind of setting.

[yuhhaurlin]

If stock firmware has the same problem, please report this problem for stock firmware. Thanks.

[ghost]

Unknown if it is the current latest driver or lede 17.01 (will take some testing) however DFS is not working on channel 52 to 144,

[yuhhaurlin]

root@LEDE:/# iw dev phy#1 Interface wlan1 ifindex 8 wdev 0x100000002 addr 00:50:43:22:88:89 ssid LEDE-8964-2g type AP channel 11 (2462 MHz), width: 20 MHz, center1: 2462 MHz txpower 30.00 dBm phy#0 Interface wlan0 ifindex 12 wdev 0x5 addr 00:50:43:22:88:8a type AP channel 100 (5500 MHz), width: 80 MHz, center1: 5530 MHz txpower 23.00 dBm root@LEDE:/# [ 1298.839376] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready [ 1298.845815] br-lan: port 4(wlan0) entered blocking state [ 1298.851140] br-lan: port 4(wlan0) entered forwarding state [ 1298.946577] IPv6: ADDRCONF(NETDEV_UP): wlan0-1: link is not ready [ 1299.086348] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0-1: link becomes ready [ 1299.181574] IPv6: ADDRCONF(NETDEV_UP): wlan0-2: link is not ready [ 1299.319360] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0-2: link becomes ready

root@LEDE:/# iw dev phy#1 Interface wlan1 ifindex 8 wdev 0x100000002 addr 00:50:43:22:88:89 ssid LEDE-8964-2g type AP channel 11 (2462 MHz), width: 20 MHz, center1: 2462 MHz txpower 30.00 dBm phy#0 Interface wlan0-2 ifindex 14 wdev 0x7 addr 06:50:43:22:88:8a ssid LEDE-8964-BSSID-2 type AP channel 100 (5500 MHz), width: 80 MHz, center1: 5530 MHz txpower 23.00 dBm Interface wlan0-1 ifindex 13 wdev 0x6 addr 02:50:43:22:88:8a ssid LEDE-8964-BSSID-1 type AP channel 100 (5500 MHz), width: 80 MHz, center1: 5530 MHz txpower 23.00 dBm Interface wlan0 ifindex 12 wdev 0x5 addr 00:50:43:22:88:8a ssid LEDE-8964-5g type AP channel 100 (5500 MHz), width: 80 MHz, center1: 5530 MHz txpower 23.00 dBm root@LEDE:/#

[yuhhaurlin]

You must wait for 60 seconds for the AP to work if there is no radar detected.

[BrainSlayer]

??? channel 52 as well as 36 has no dfs requirement.

[yuhhaurlin]

country US: DFS-FCC (2402 - 2472 @ 40), (N/A, 30), (N/A) (5170 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW (5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW (5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS (5735 - 5835 @ 80), (N/A, 30), (N/A) (57240 - 63720 @ 2160), (N/A, 40), (N/A)

If you set channel 36 (160 MHz), it needs DFS working to allow this setting. You need to wait for 60 seconds to let the AP work if no radar detected. I also tried channel 100 (80 Mhz), it can work. Please check the log I just sent out.

[yuhhaurlin]

If you set DFS channels to device, you can't find SSID when you issue "iw dev" until CAC is done (60 seconds). After CAC is done, you can find SSID when you issue "iw dev". It means the AP is working.

[vit5421]

Dear Yuhhaurlin, Do you have any solution for 2.4 upstream slowdown?

[yuhhaurlin]

Does stock firmware have the same problem?

[vit5421]

I will flash the latest 1.0.6.181063 stock and test it during the day

[tapper82]

getting 2.4 slow down on. Firmware Version LEDE Reboot SNAPSHOT r4290-9e1bc27 / LuCI Master (git-17.150.76278-0e9eed5) Kernel Version 4.9.30

[vit5421]

Works great for 1 hour on stock driver. 2.4 and 5 looks very good. There is no 2.4 slowdown and 5 is even more stable. I dont see any single slowdown on 5 during huge file downloads/uploads but it happens on open source driver. Will tested more and report later

[vit5421]

getting 2.4 slow down in 6 hours. The upstream speed is 2 mbs instead of 60 but downstream is fast as usual. So, the stock driver have the same problem as open source.

[ghost]

--- Sorry for last post, the iperf copy and paste got mixed up ---

I was wrong about stock not being affected, I just reset wifi config on lede and still have major slowdown on 2.4ghz 20/40mhz.

WRT3200ACM - LEDE 17.01 - Latest Mwlwifi

Wan Link: 65Mbit (63750 Kbit QOS) Down / 6.5 Mbit (6400 Kbit QOS) Up

iperf3.exe -c XXXXX -t20 -i2 -w512k --- 2.4 Ghz --- Ch 6+10 40 Mhz Upload > iperf server (private server over wan) [ ID] Interval Transfer Bandwidth [ 4] 0.00-2.00 sec 1.62 MBytes 6.81 Mbits/sec [ 4] 2.00-4.00 sec 1.25 MBytes 5.24 Mbits/sec [ 4] 4.00-6.00 sec 1.38 MBytes 5.77 Mbits/sec [ 4] 6.00-8.00 sec 896 KBytes 3.67 Mbits/sec [ 4] 8.00-10.00 sec 256 KBytes 1.05 Mbits/sec [ 4] 10.00-12.00 sec 640 KBytes 2.62 Mbits/sec [ 4] 12.00-14.00 sec 384 KBytes 1.57 Mbits/sec [ 4] 14.00-16.00 sec 512 KBytes 2.10 Mbits/sec [ 4] 16.00-18.00 sec 384 KBytes 1.57 Mbits/sec [ 4] 18.00-20.00 sec 384 KBytes 1.57 Mbits/sec

---

[ ID] Interval Transfer Bandwidth [ 4] 0.00-20.00 sec 7.62 MBytes 3.20 Mbits/sec sender [ 4] 0.00-20.00 sec 7.20 MBytes 3.02 Mbits/sec receiver

iperf3.exe -c XXXXX -t20 -i2 -w512k -R Download (Reserve Mode) [ ID] Interval Transfer Bandwidth [ 4] 0.00-2.00 sec 11.0 MBytes 46.1 Mbits/sec [ 4] 2.00-4.00 sec 12.0 MBytes 50.2 Mbits/sec [ 4] 4.00-6.00 sec 7.88 MBytes 33.1 Mbits/sec [ 4] 6.00-8.00 sec 7.80 MBytes 32.7 Mbits/sec [ 4] 8.00-10.00 sec 7.46 MBytes 31.3 Mbits/sec [ 4] 10.00-12.00 sec 10.6 MBytes 44.6 Mbits/sec [ 4] 12.00-14.00 sec 9.43 MBytes 39.6 Mbits/sec [ 4] 14.00-16.00 sec 8.52 MBytes 35.7 Mbits/sec [ 4] 16.00-18.00 sec 8.95 MBytes 37.6 Mbits/sec [ 4] 18.00-20.00 sec 5.28 MBytes 22.1 Mbits/sec

---

[ ID] Interval Transfer Bandwidth Retr [ 4] 0.00-20.00 sec 89.4 MBytes 37.5 Mbits/sec 16 sender [ 4] 0.00-20.00 sec 89.3 MBytes 37.5 Mbits/sec receiver

iperf3.exe -c XXXXX -t20 -i2 -w512k --- 5 Ghz --- Ch. 136 DFS / 5730-5650 80 Mhz Upload -- [ ID] Interval Transfer Bandwidth [ 4] 0.00-2.00 sec 1.75 MBytes 7.34 Mbits/sec [ 4] 2.00-4.00 sec 1.38 MBytes 5.77 Mbits/sec [ 4] 4.00-6.00 sec 1.00 MBytes 4.19 Mbits/sec [ 4] 6.00-8.00 sec 1.38 MBytes 5.77 Mbits/sec [ 4] 8.00-10.00 sec 1.38 MBytes 5.77 Mbits/sec [ 4] 10.00-12.00 sec 1.38 MBytes 5.77 Mbits/sec [ 4] 12.00-14.00 sec 1.38 MBytes 5.77 Mbits/sec [ 4] 14.00-16.00 sec 1.38 MBytes 5.77 Mbits/sec [ 4] 16.00-18.00 sec 1.38 MBytes 5.77 Mbits/sec [ 4] 18.00-20.00 sec 1.38 MBytes 5.77 Mbits/sec

---

[ ID] Interval Transfer Bandwidth [ 4] 0.00-20.00 sec 13.8 MBytes 5.77 Mbits/sec sender [ 4] 0.00-20.00 sec 13.3 MBytes 5.57 Mbits/sec receiver

iperf3.exe -c XXXXX -t20 -i2 -w512k -R Download (Reserve Mode) [ ID] Interval Transfer Bandwidth [ 4] 0.00-2.00 sec 13.3 MBytes 56.0 Mbits/sec [ 4] 2.00-4.00 sec 13.9 MBytes 58.5 Mbits/sec [ 4] 4.00-6.00 sec 14.2 MBytes 59.4 Mbits/sec [ 4] 6.00-8.00 sec 13.9 MBytes 58.3 Mbits/sec [ 4] 8.00-10.00 sec 14.1 MBytes 59.2 Mbits/sec [ 4] 10.00-12.00 sec 13.9 MBytes 58.5 Mbits/sec [ 4] 12.00-14.00 sec 14.2 MBytes 59.7 Mbits/sec [ 4] 14.00-16.00 sec 14.0 MBytes 58.7 Mbits/sec [ 4] 16.00-18.00 sec 13.9 MBytes 58.1 Mbits/sec [ 4] 18.00-20.00 sec 13.9 MBytes 58.4 Mbits/sec

---

[ ID] Interval Transfer Bandwidth Retr [ 4] 0.00-20.00 sec 140 MBytes 58.6 Mbits/sec 27 sender [ 4] 0.00-20.00 sec 140 MBytes 58.6 Mbits/sec receiver

--- DFS Issue --- I have found the issue with DFS not working, it was not caused by driver. Appears to be something LEDE may need to fix (DD-WRT also may be affected), any reconfiguration of phy#2 (third wifi) interferes with DFS/Radar checking.

Corrected fix: LEDE rm -f /etc/config/wireless wifi detect > /etc/config/wireless reboot

[vit5421]

So, we have 2.4 issues on stock and open source driver. Btw, 5 ghz works more stable and faster on stock driver for sure. Unfortunately, i have to return my two 3200 units coz of issues

[yuhhaurlin]

@rs-se

1. Does the slowdown of upload (STA to AP) for 2.4g only happen for specific client? If yes, which one?
2. phy2 is not mwlwifi.

[vit5421]

when its happens then all clients like windows 7 and 10 and Androids getting the same slow speed,

[yuhhaurlin]

@vit5421 Thanks. I will do tests later.

[vit5421]

I would like to mention one more time that power reset will not help but when i move close to router the speed will be restored. Sometimes it works ok for hours and stuck after that.. I have to return routers by Friday. so will be nice to know

[yuhhaurlin]

This issue will be checked later. Thanks.

[yuhhaurlin]

@vit5421 In fact, for upload, the role of AP is receiving. Can you test these clients one by one to see if the problem only happened for specific client? Or can you use sniffer to capture traffic between AP and client?

[vit5421]

I tested all clients one by one and can confirm that problem is related to all clients at the same time. The 3200 is disconnected now because of issues and wrt1900acs is handling the wifi right now. It will be nice to have a Status/Wireless info in order to see the negotiated Tx rate

[ghost]

@yuhhaurlin

AP mode, I have been able to confirm with 2.4ghz under 20mhz speeds are unstable, after I changed it to 40mhz it was much more stable.

phy2, was only referenced as it appears to have been interfering with phy0. Might be a linksys/opensource problem to look into.

[yuhhaurlin]

1. In real work, 11n 40 Mhz is hard to really work unless your environment is very clean, otherwise, hostapd will do overlay BSSes check to decide if 40 MHz is allowable and most of the time, 40 Mhz is not allowable and will change back to 20 Mhz by hostapd.
2. You can change interrupts of phy 5g to another core via /proc/irq/irq_num of phy 5g/smp_affinity.

[vit5421]

20 is a preferable choice of course. Do you think i can try just for test to use the 20/40 or even 40 in settings?

[ghost]

In my area, 40Mhz is to put it plainly a "jerk move" due to 2.4ghz saturation. Unknown why 20mhz is unstable under AP mode.

[vit5421]

My neighbours signals are at the floor level around 92-95 dbm, so my major problem for 40 is my 2nd AP. I can have 40 on main AP and 20 on other. But, this issue needs to be specified and fixed asap

[yuhhaurlin]

What do you mean unstable? The same as upload slowdown for 2.4g? And from the description, it is related to distance between AP and client. Can you give me detail information about the distance and test procedure?

BTW, how many users encounter this kind of problem?

[vit5421]

Dear yuhhaurlin, I did try different settings like Mixed mode and 20/40 mbps. It worked for several hours and then upsteram only stuck as usual at 2-4mbps on all clients and i was not able to start it again even with disabling wifi on router and router restart. Another words i completely give up coz spent all week for troubleshooting and will return routers tomorrow. I hope problem will be fixed later

[yuhhaurlin]

If I use one client and run iperf test, I can reproduce this problem, right? What is the distance between AP and client?

Are you sure wrt1200 and wrt1900 work well under same test?

[vit5421]

I think u can reproduce it but its unpredictable. I am more than 100% sure that wrt1900acs works well on any distance for month. U can use any speed test to be sure. The distance is not very big like 20-30 feet or so but it looks like router is triggering the wrong rate and hold it until u will stay closer and will continue to be slow if you will stay far

[yuhhaurlin]

If the problem happened for Tx (AP to STA ), it could be rate adaptation problem of AP (It should be recovered after reboot). But the problem is related to Rx (STA to AP), the only possibility is that AP does not receive packets from STA. If the distance is so close and it can run for a long time, restart can't recover the problem, it is very strange. And there is no this kind of problem for 5g band.

Is there any other one got this kind of problem？

[yuhhaurlin]

Can you try another WRT3200ACM?

[vit5421]

The problem is related to 2.4 Ghz Tx only on both wrt3200 routers, 5g is fine. May be both are defected in the same way? idk

[yuhhaurlin]

Tx? The problem is upload, it should be Rx of AP. When the problem happened, can you power off AP and wait for a while before restarting AP to check if the problem is still there.

If possible, please try another WRT3200ACM.

[yuhhaurlin]

If the problem happen for Tx and It can't be recovered by reboot, it is not rate adaptation problem of AP. I suggest:

1. When problem happened, power off AP for a while and restart again to see if problem is still there.
2. Try another WRT3200ACM.