Subject: rt2800usb (rt2x00) in ad-hoc mode stalls when transferring large amount of data

Hello

I have a Ralink 3071 usb device (Bus 002 Device 003: ID 07b8:3071
D-Link Corp. 802.11n/b/g Mini Wireless LAN USB2.0 Adapter).
I am using the mac80211 driver by compiling the compat-wireless
tarball from yesterday (10 March). I cross compile it with the 2.6.24
kernel in a Montavista distribution (and also with 2.6.27 in Fedora)

It works pretty good in AP mode using HostAPD and DCHP and I get
relative good transfer rates (up to 3.5 MBytes per second).

My problems are with Ad-Hoc connections. I can configure the Ad-Hoc
connection, for example:

iwconfig wlan0 mode ad-hoc
iwconfig wlan0 essid my_ad_hoc_nt
iwconfig wlan0 key 1122334455
ifconfig wlan0 192.168.111.44 up

It works and I connect to it on the other end (a windows machine with
a compatible static ip address), however, it only works for doing
small data transfer rate things like browsing through the directories
of a shared folder or retrieving web pages from a web server. When I
try to do something like transferring a 500 MByte file, it starts
transferring, reaches a peak and then it drops to 0 again. After that,
the file is no longer transferred and I cannot do anything else (can't
ping).

Is this a known issue? Any ideas?

Juan Carlos


Subject: Re: rt2800usb (rt2x00) in ad-hoc mode stalls when transferring large amount of data

On Fri, Mar 11, 2011 at 9:08 PM, Luis Correia <[email protected]> wrote:
> Hi
>
> On Fri, Mar 11, 2011 at 20:04, Juan Carlos Garza
> <[email protected]> wrote:
>> Hello
>>
>> I have a Ralink 3071 usb device (Bus 002 Device 003: ID 07b8:3071
>> D-Link Corp. 802.11n/b/g Mini Wireless LAN USB2.0 Adapter).
>> I am using the mac80211 driver by compiling the compat-wireless
>> tarball from yesterday (10 March). I cross compile it with the 2.6.24
>> kernel in a Montavista distribution (and also with 2.6.27 in Fedora)
>>
>> It works pretty good in AP mode using HostAPD and DCHP and I get
>> relative good transfer rates (up to 3.5 MBytes per second).
>>
>> My problems are with Ad-Hoc connections. I can configure the Ad-Hoc
>> connection, for example:
>>
>> iwconfig wlan0 mode ad-hoc
>> iwconfig wlan0 essid my_ad_hoc_nt
>> iwconfig wlan0 key 1122334455
>> ifconfig wlan0 192.168.111.44 up
>>
>> It works and I connect to it on the other end (a windows machine with
>> a compatible static ip address), however, it only works for doing
>> small data transfer rate things like browsing through the directories
>> of a shared folder or retrieving web pages from a web server. When I
>> try to do something like transferring a 500 MByte file, it starts
>> transferring, reaches a peak and then it drops to 0 again. After that,
>> the file is no longer transferred and I cannot do anything else (can't
>> ping).
>>
>> Is this a known issue? Any ideas?
>>
>> Juan Carlos
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
>> the body of a message to [email protected]
>> More majordomo info at ?http://vger.kernel.org/majordomo-info.html
>>
>
> keep in mind that current (and by design) ad-hoc connections max out at 11Mb.

Thanks for the comment,
Mhh, I've been benchmarking some other chipsets in ad-hoc mode (like
the rtl8188cus) and they do not present these problems (only a slow
transfer rate).

>
> there may be some buffer bottleneck involved.
>

I tried changing the MTU and other parameters, and nothing...

> but I'm not a very good expert on this subject.
>
>
> Luis Correia
>



--
________________________________
M.Sc. Juan Carlos Garza Fern?ndez
Chistophstr. 14
70178 Stuttgart, Deutschland
+49 711 4080769
+49 176 21947676
[email protected]
________________________________

2011-03-11 20:08:55

by Luis Correia

[permalink] [raw]
Subject: Re: rt2800usb (rt2x00) in ad-hoc mode stalls when transferring large amount of data

Hi

On Fri, Mar 11, 2011 at 20:04, Juan Carlos Garza
<[email protected]> wrote:
> Hello
>
> I have a Ralink 3071 usb device (Bus 002 Device 003: ID 07b8:3071
> D-Link Corp. 802.11n/b/g Mini Wireless LAN USB2.0 Adapter).
> I am using the mac80211 driver by compiling the compat-wireless
> tarball from yesterday (10 March). I cross compile it with the 2.6.24
> kernel in a Montavista distribution (and also with 2.6.27 in Fedora)
>
> It works pretty good in AP mode using HostAPD and DCHP and I get
> relative good transfer rates (up to 3.5 MBytes per second).
>
> My problems are with Ad-Hoc connections. I can configure the Ad-Hoc
> connection, for example:
>
> iwconfig wlan0 mode ad-hoc
> iwconfig wlan0 essid my_ad_hoc_nt
> iwconfig wlan0 key 1122334455
> ifconfig wlan0 192.168.111.44 up
>
> It works and I connect to it on the other end (a windows machine with
> a compatible static ip address), however, it only works for doing
> small data transfer rate things like browsing through the directories
> of a shared folder or retrieving web pages from a web server. When I
> try to do something like transferring a 500 MByte file, it starts
> transferring, reaches a peak and then it drops to 0 again. After that,
> the file is no longer transferred and I cannot do anything else (can't
> ping).
>
> Is this a known issue? Any ideas?
>
> Juan Carlos
> --
> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
> the body of a message to [email protected]
> More majordomo info at ?http://vger.kernel.org/majordomo-info.html
>

keep in mind that current (and by design) ad-hoc connections max out at 11Mb.

there may be some buffer bottleneck involved.

but I'm not a very good expert on this subject.


Luis Correia