Re: r8712u: packet loss

Re: r8712u: packet loss

[Ben Ruijl]

I am experiencing packet loss of about 12 percent with the r8712u
staging driver with my WL-352v2 device. I'm not the only one with this
problem (https://bbs.archlinux.org/viewtopic.php?id=112120). I haven't
done a git bisect yet, but I know the problem is in both the 2.6.37
version and the latest version.

Regards,

Ben

Re: r8712u: packet loss

[Larry Finger]

On 02/15/2011 06:58 AM, Ben Ruijl wrote:
> I am experiencing packet loss of about 12 percent with the r8712u
> staging driver with my WL-352v2 device. I'm not the only one with this
> problem (https://bbs.archlinux.org/viewtopic.php?id=112120). I haven't
> done a git bisect yet, but I know the problem is in both the 2.6.37
> version and the latest version.

Normally, you should not expect to get much help in this mailing list with a 
driver from staging. I assume that you have seen the warning that is placed in 
the dmesg output when you load a staging driver. You are fortunate in this case 
as I was the one that pushed this driver into staging.

A bisection would not do much good as there have been few changes to the driver 
since it was included.

Please describe your case more completely. List the output of iwconfig. I need 
this info as my device gets a ping packet loss of about 1%.

Larry

Re: r8712u: packet loss

[Ben Ruijl]

Hi Larry,

Thanks for your response. I didn't really know where to post the
issue. I won't be able to post the output of iwconfig to you until
Friday, since I don't have the usb stick right now. I can give you the
output of ifconfig, though:

wlan0     Link encap:Ethernet  HWaddr 00:0C:F6:9E:31:6B
          inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:f6ff:fe9e:316b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2848 errors:0 dropped:419 overruns:0 frame:0
          TX packets:2597 errors:0 dropped:119 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:2130344 (2.0 Mb)  TX bytes:527557 (515.1 Kb)

ben@PC_ONDER ~ $ ifconfig
wlan0     Link encap:Ethernet  HWaddr 00:0C:F6:9E:31:6B
          inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:f6ff:fe9e:316b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4415 errors:0 dropped:580 overruns:0 frame:0
          TX packets:3460 errors:0 dropped:119 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:4356319 (4.1 Mb)  TX bytes:635028 (620.1 Kb)

ben@PC_ONDER ~ $ ifconfig
wlan0     Link encap:Ethernet  HWaddr 00:0C:F6:9E:31:6B
          inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:f6ff:fe9e:316b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4424 errors:0 dropped:582 overruns:0 frame:0
          TX packets:3468 errors:0 dropped:119 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:4358105 (4.1 Mb)  TX bytes:636067 (621.1 Kb)

I posted this in a topic on the arch linux forum
(https://bbs.archlinux.org/viewtopic.php?id=112120). There is also
another user with the same problems and he posted his ifconfig too.
lsusb -v recognizes the chipset as RTL8191su.

I hope this helps!

Ben

2011/2/15 Larry Finger <Larry.Finger@lwfinger.net>:
> On 02/15/2011 06:58 AM, Ben Ruijl wrote:
>>
>> I am experiencing packet loss of about 12 percent with the r8712u
>> staging driver with my WL-352v2 device. I'm not the only one with this
>> problem (https://bbs.archlinux.org/viewtopic.php?id=112120). I haven't
>> done a git bisect yet, but I know the problem is in both the 2.6.37
>> version and the latest version.
>
> Normally, you should not expect to get much help in this mailing list with a
> driver from staging. I assume that you have seen the warning that is placed
> in the dmesg output when you load a staging driver. You are fortunate in
> this case as I was the one that pushed this driver into staging.
>
> A bisection would not do much good as there have been few changes to the
> driver since it was included.
>
> Please describe your case more completely. List the output of iwconfig. I
> need this info as my device gets a ping packet loss of about 1%.
>
> Larry
>



-- 
Ben Ruijl
PGP 825472FC

Re: r8712u: packet loss

[Larry Finger]

On 02/15/2011 11:20 AM, Ben Ruijl wrote:
> Hi Larry,
>
> Thanks for your response. I didn't really know where to post the
> issue. I won't be able to post the output of iwconfig to you until
> Friday, since I don't have the usb stick right now. I can give you the
> output of ifconfig, though:

No, I need to know the signal strength to see if your conditions are much 
different than mine.

Larry

Re: r8712u: packet loss

[Ben Ruijl]

Here is the output of iwconfig:

wlan0     IEEE 802.11bg  ESSID:"H23"  Nickname:"rtl_wifi"
          Mode:Managed  Frequency:2.452 GHz  Access Point: 00:23:54:A6:EF:A4
          Bit Rate:54 Mb/s   Sensitivity:0/0
          Retry:off   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=100/100  Signal level=69/100  Noise level=0/100
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

The link quality varies between 99 and 100, but is almost always 100.
The signal level varies between 62 and 69.

Ben

Re: r8712u: packet loss

[Ben Ruijl]

Hi Larry,

The iwconfig I sent you is wrong, because I switched routers. The
router I had was a wireless N router, with which I had 12 percent
packet loss. The iwconfig you are seeing is with a wireless G
connection and now I only have 1 percent packet loss: the same as you
have. It appears that the relative packet loss is greater with an N
connection.

Ben

2011/2/18 Ben Ruijl <benruyl@gmail.com>:
> Here is the output of iwconfig:
>
> wlan0     IEEE 802.11bg  ESSID:"H23"  Nickname:"rtl_wifi"
>          Mode:Managed  Frequency:2.452 GHz  Access Point: 00:23:54:A6:EF:A4
>          Bit Rate:54 Mb/s   Sensitivity:0/0
>          Retry:off   RTS thr:off   Fragment thr:off
>          Power Management:off
>          Link Quality=100/100  Signal level=69/100  Noise level=0/100
>          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
>          Tx excessive retries:0  Invalid misc:0   Missed beacon:0
>
> The link quality varies between 99 and 100, but is almost always 100.
> The signal level varies between 62 and 69.
>
> Ben
>



-- 
Ben Ruijl
PGP 825472FC

Re: r8712u: packet loss

[Larry Finger]

On 03/06/2011 03:52 AM, Ben Ruijl wrote:
> Hi Larry,
>
> The iwconfig I sent you is wrong, because I switched routers. The
> router I had was a wireless N router, with which I had 12 percent
> packet loss. The iwconfig you are seeing is with a wireless G
> connection and now I only have 1 percent packet loss: the same as you
> have. It appears that the relative packet loss is greater with an N
> connection.

I have no idea why the loss should be greater with the N router than with the G 
router.

How is the 2.4 GHz part of the N router configured? What make/model is it, and 
what firmware is it running? Do you have the latest version?

My N router is a Netgear WNDR3300 normally running up to 270 Mbps at 5 GHz and 
54 Mbps at 2.4 GHz; however, I changed it to run up to 270 Mbps in the 2.4 GHz 
band. Again, I get 1% ping loss. My iwconfig output is

wlan12    IEEE 802.11bgn  ESSID:"lwfdjf-n"  Nickname:"rtl_wifi"
           Mode:Managed  Frequency:2.422 GHz  Access Point: C0:3F:0E:BE:2B:44
           Bit Rate:270 Mb/s   Sensitivity:0/0
           Retry:off   RTS thr:off   Fragment thr:off
           Power Management:off
           Link Quality=97/100  Signal level=100/100  Noise level=0/100
           Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
           Tx excessive retries:0  Invalid misc:0   Missed beacon:0


That link gets an upload speed measured with tcpperf of more than 80 Mbps.

I do not know why your N link is so lossy. The possible reasons are outdated 
firmware in the router that was established in the pre-N days, or you have 
noise/interference that affects the HT setup more than a simple G configuration.

Larry