Author Topic: WZR-HP-G300NH periodic wireless dropouts  (Read 10863 times)

barneyzang1

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WZR-HP-G300NH periodic wireless dropouts
« on: January 23, 2014, 12:17:35 am »
I've had a WZR-HP-G300NH (v1) router for a while now, and I'm finally getting around to writing about some frustrating wireless behavior that has been occurring for as long as I've owned the device.  The basic symptom is that periodically all wireless connections fail (sometimes a couple of times a day, sometimes days apart).  The SSID still appears, but connected devices are no longer able to send packets -- pings fail, can't connect to the admin page, etc.  Sometimes the device recovers after a long while.  Sometimes I have to walk across the house and power-cycle it.

The same basic symptoms occur whether I'm running builds acquired directly from the dd-wrt website (I've cycled through many over the course of two years -- 17461, 19519, 21676, 21286) or the latest officially blessed builds from Buffalo (19484 what I'm currently running now).

In the failure state (usually after a while), sometimes the pings start to get through and look like this:
Code: [Select]
Request timeout for icmp_seq 40
Request timeout for icmp_seq 41
64 bytes from 192.168.1.1: icmp_seq=42 ttl=64 time=599.500 ms
64 bytes from 192.168.1.1: icmp_seq=43 ttl=64 time=138.058 ms
64 bytes from 192.168.1.1: icmp_seq=44 ttl=64 time=779.801 ms
Request timeout for icmp_seq 45
Request timeout for icmp_seq 46

I've tried looking at the syslog (setup via instructions here: http://www.dd-wrt.com/wiki/index.php/Logging_with_DD-WRT), but nothing appears unusual.

I've tried several different suggestions found on the forums without any luck:
http://www.dd-wrt.com/phpBB2/viewtopic.php?t=72949&view=previous&sid=01a0c337051a6ef234f169518cf2d5a1
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=712104
http://dd-wrt.com/wiki/index.php/Buffalo_WZR-HP-G300NH#WZR-HP-G300NH2_and_WZR-300HP
http://www.amazon.com/review/R2DIOWAYT6PO8C/ref=cm_cr_quotes_dprb_2?ie=UTF8&ASIN=B0028ACYEK
http://g300nh.blogspot.com/2010/06/temporary-fix-for-stuck-beacon-problem.html
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=614670&sid=3db9e620c81cbaf7d0696b619175dc45
http://svn.dd-wrt.com/ticket/1500 -- haven't tried the script at the end of this one yet
https://dev.openwrt.org/ticket/8343 -- (not dd-wrt, but could be related)

Some details about my setup:
device:  WZR-HP-G300NH (v1)
build:    DD-WRT v24SP2-MULTI (07/15/12) std - build 19484
Wireless-N only, channel 6 (fixed)
No WEP/Security Password (I use MAC filtering to only permit certain devices to connect)
No bitorrent running
No optware
No USB drive attached
Wirelessly connected devices include the usual smattering of mobile devices, iPads, a wireless bridge (that I've ruled out of being a problem by disconnecting it for a few days)

In my frustration, I even purchased a new WHR-300HP and had almost exactly the same behavior.  Given that the same behavior occurs on both devices, I'm inclined to think there's a serious software issue here.

I'd appreciate any guidance from Buffalo support or other forum members about further options for debugging and/or isolating this behavior.

Thanks!

barneyzang1

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #1 on: January 26, 2014, 11:47:41 pm »
Hit the problem again tonight and noticed these messages in the log

Code: [Select]
Jan 26 17:42:08 kern.err kernel: [45697.430000] ath: phy0: Failed to stop TX DMA, queues=0x100!
Jan 26 17:42:09 kern.err kernel: [45697.680000] ath: phy0: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 DMADBG_7=0x00026020
Jan 26 17:42:09 kern.err kernel: [45697.690000] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jan 26 17:42:09 kern.err kernel: [45697.930000] ath: phy0: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 DMADBG_7=0x00026020
Jan 26 17:42:09 kern.err kernel: [45697.940000] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up

These look suspiciously like the behavior in these posts:

http://forums.buffalotech.com/index.php?topic=14991.0
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=671020
https://dev.openwrt.org/ticket/9654

A few more details -- I am able to connect to the router from a direct wired connection.
« Last Edit: January 31, 2014, 10:28:13 am by barneyzang1 »

barneyzang1

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #2 on: February 17, 2014, 12:13:25 pm »
Gave up.  Wish I had done so earlier.

Purchased an EnGenius ECB300 Client Bridge (http://www.engeniustech.com/business-networking/indoor-access-points-client-bridges/16363-ecb300) over the weekend.  New device has a *much* stronger signal, *much* higher throughput (between 3-4x), plays well with all other devices, and (most importantly) doesn't drop out.

I've kept my WZR-HP-G300NH hanging around as the internet-facing gateway/router, but have turned off its wireless radio.  There's something fundamentally broken with the wireless stack on these devices.

I have been a big fan of Buffalo products in the past (even went so far as to buy a WHR-300HP to try and isolate this issue), but will likely not be choosing a Buffalo product in the future. 


AhuraMazda

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #3 on: February 18, 2014, 06:13:17 am »
Try this:
N/G
Turbo 40Mhz
rts/cts ON
Fixed channel
most important: ACK Timing 300 or 0... If u use it in a house I suggest 300

barneyzang1

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #4 on: February 26, 2014, 01:09:38 am »
Ran two more tests for the last week to see if there was any improvement with the suggested settings:
For both tests, set N/G, Turbo 40MHz, rts/crs On, fixed channel (6):

Test 1. Set ACK Timing to 300 -- still hit the failures (long ping times, much lower throughput); within the first day
Test 2. Set ACK Timing to 0 -- hit similar failures, but they took longer to occur (long ping times, lower throughput); after several days of running

The only common thread to the failures is they seem to mostly occur when doing large wireless transfers from the router to my computer (same as before).  However, this may be the time when I'm most likely to notice such a failure.

These updated settings offer an improvement, but it's still not rock-solid/forget-about-it reliability -- so I've turned back on the Engenius WAP.

AhuraMazda

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #5 on: February 28, 2014, 07:51:23 am »
Barney what is your tx power? (Wireless\Advanced settings)

AhuraMazda

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #6 on: February 28, 2014, 07:56:50 am »
Please, do one more test with these settings. For Regulatory domain choose New_Zeland and>
Tx power 22
Antenna gain 5
TX Antenna Chains: 1+3
RX Antenna Chains: 1+2+3
post pingtest to 8.8.8.8  but with no torrent and heavy download. Line must be in idle state...
« Last Edit: February 28, 2014, 08:00:51 am by AhuraMazda »

granchi

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #7 on: March 01, 2014, 09:32:59 am »
Same problem with a WHR-HP-G300N.

T.

Mighty_Joe

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #8 on: March 12, 2014, 07:39:03 am »
I had this same problem with a WZR-300HP running DD-WRT v24SP2-MULTI (07/09/12) std - build 19438. 
While I was waiting on hold for Buffalo Tech Support (they actually do answer the phone, apparently they ignore these forums)  I discovered the IP Filter Settings on the Administration -> Management page.  It appears that the default for Maximum Ports is 4096 and the default for TCP Timeout is 3600 seconds.  The router will run out of ports quickly if you are doing any IM or P2P. 
See the http://www.dd-wrt.com/wiki/index.php/Router_Slowdown for the rationalization, but understand that it is a few years out of date. 

I changed the Maximum Ports setting to the DD-WRT "default", which is 32768 and the TCP Timeout to 360 seconds (word on the street is many applications expect a 300+ timeout). 
These changes took care of the wireless timeouts, but I now had problems with large file transfers and streaming radio stalling after a few minutes.  Searching for this problem didn't get me anywhere, so I decided to reset the router, thinking my firmware upgrades had simply gotten confused:
https://secure.dd-wrt.com/wiki/index.php/Reset_And_Reboot
I made my normal configuration changes plus the ports and timeout settings above (the reset changed them back to 4096/3600).  It has been up for 24 hours and everything appears to be functioning normally.

Pada

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #9 on: March 15, 2014, 04:06:05 pm »
Thanks for the info.

I also tried the wzrhpg300nh-pro-v24sp2-19484-beta, but my WiFi was very unstable! Like when I ran ping, it dropped every 4th packet even!
The stock "Friendly" v1.79 was also unstable where the AP just disappeared.

I've now changed over to BrainSlayer's DD-WRT r22118 build and the past 18 hours it has been stable!
I did however change the TCP settings to like what you suggested: 32768 ports & 300s timeout. I also disabled the firewall and assigned the WAN port to the switch, because I have another router for my WAN connection.

Stark Reality

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Re: WZR-HP-G300NH periodic wireless dropouts
« Reply #10 on: March 22, 2014, 12:08:12 pm »
Can Buffalo please update the "FRIENDLY" and "PROFESSIONAL" firmware now that dd-wrt and open-wrt have patched their ath9k?

Oh, and please set the defaults to better values?

For info to Buffalo: I had to retire several Buffalo N routers (e.g. WHR-HP-G300N) within a week because of these issues. Had to endure a scolding from CIO for setting up these crappy routers and hanging users' wireless adapters. You really let me down.