[ath9k-devel] ath9k: Virtual interface as AP

[ath9k-devel] ath9k: Virtual interface as AP

["Lorna González"]

Hello, 

I am trying to build a virtual interface (not wiphy) operating in master mode using hostapd. Using wiphys (echo > add ...wiphy) I am able to configurate a wiphy as station and another one as AP. It works perfectly but by setting the AP creating a new interface as:

iw phy phy0 interface add wlan1 type master 

and changing its MAC Adress, it does not work. Other stations can not find this virtual AP. 

Can anyone tell me if I need extra configurations?

Thanks in advanced

Lorna Glez.  
-- 
GMX DSL Doppel-Flat ab 19,99 €/mtl.! Jetzt auch mit 
gratis Notebook-Flat! http://portal.gmx.net/de/go/dsl

[ath9k-devel] ath9k: Virtual interface as AP

[Jouni Malinen]

On Wed, 2010-10-27 at 04:11 -0700, "Lorna Gonz?lez" wrote:
> I am trying to build a virtual interface (not wiphy) operating in master mode using hostapd. Using wiphys (echo > add ...wiphy) I am able to configurate a wiphy as station and another one as AP. It works perfectly but by setting the AP creating a new interface as:
> 
> iw phy phy0 interface add wlan1 type master 
> 
> and changing its MAC Adress, it does not work. Other stations can not find this virtual AP. 

I would recommend using hostapd to add/remove those interfaces, i.e., do
not use iw manually, but add new bss=<ifname> entries to the end of
hostapd.conf.

- Jouni

[ath9k-devel] ath9k: Virtual interface as AP

["Lorna González"]

Thanks Mr. Malinen for your reply. I tried to add my interface using hostapd but I get following:

Configuration file: hostapd.conf
ioctl[SIOCGIFFLAGS]: No such device
Could not read interface flags (wlan1)
nl80211 driver initialization failed.
wlan1: Unable to setup interface.
Segmentation fault

My hostapd.conf looks like:

interface=wlan1
driver=nl80211
bridge=br0
hw_mode=g
channel=5
ssid=VirtualAP
auth_algs=1
bss=wlan1
#bssid=00:22:43:21:82:ad

If I don?t add a new interface using iw, I wonder how the hostapd creates it. And, in order to function as an AP I also need to configurate the following a priori :

1.Assign IP
sudo ifconfig wlan1 192.168.1.1

2.Enable forwarding

3.Eenable masquerading

By using wiphys this is normally not a problem since I add a wiphy before initiating hostapd. 



Thanks for your response

Lorna Glenz. 




-- 
GRATIS! Movie-FLAT mit ?ber 300 Videos. 
Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome

[ath9k-devel] ath9k: Virtual interface as AP

[Mohammed Shafi]

2010/10/27 "Lorna Gonz?lez" <lorna.glez@gmx.net>:
>
> Thanks Mr. Malinen for your reply. I tried to add my interface using hostapd but I get following:
>
> Configuration file: hostapd.conf
> ioctl[SIOCGIFFLAGS]: No such device
> Could not read interface flags (wlan1)
> nl80211 driver initialization failed.
> wlan1: Unable to setup interface.
> Segmentation fault
Hi have you checked whether  the interface-wlan1 is not correct may be
wlan0 or something else ?
>
> My hostapd.conf looks like:
>
> interface=wlan1
> driver=nl80211
> bridge=br0
> hw_mode=g
> channel=5
> ssid=VirtualAP
> auth_algs=1
> bss=wlan1
> #bssid=00:22:43:21:82:ad
>
> If I don?t add a new interface using iw, I wonder how the hostapd creates it. And, in order to function as an AP I also need to configurate the following a priori :
>
> 1.Assign IP
> sudo ifconfig wlan1 192.168.1.1
>
> 2.Enable forwarding
>
> 3.Eenable masquerading
>
> By using wiphys this is normally not a problem since I add a wiphy before initiating hostapd.
>
>
>
> Thanks for your response
>
> Lorna Glenz.
>
>
>
>
> --
> GRATIS! Movie-FLAT mit ?ber 300 Videos.
> Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>

[ath9k-devel] ath9k: Virtual interface as AP

["Lorna González"]

Hi Mr. Shafi, 

I am using wlan0 as a station interface but yes, I already tried to use it as AP and wlan1 as station but acording to 
# hostapd will generate BSSID mask based on the BSSIDs that are
# configured. hostapd will verify that dev_addr & MASK == dev_addr.

hostapd changed the BSSID without succesfull. 

So it does not work either. 

Thanks 


-------- Original-Nachricht --------
> Datum: Wed, 27 Oct 2010 19:54:39 +0530
> Von: Mohammed Shafi <shafi.wireless@gmail.com>
> An: "Lorna Gonz?lez" <lorna.glez@gmx.net>
> CC: ath9k-devel-request at lists.ath9k.org, ath9k-devel at lists.ath9k.org
> Betreff: Re: [ath9k-devel] ath9k: Virtual interface as AP

> 2010/10/27 "Lorna Gonz?lez" <lorna.glez@gmx.net>:
> >
> > Thanks Mr. Malinen for your reply. I tried to add my interface using
> hostapd but I get following:
> >
> > Configuration file: hostapd.conf
> > ioctl[SIOCGIFFLAGS]: No such device
> > Could not read interface flags (wlan1)
> > nl80211 driver initialization failed.
> > wlan1: Unable to setup interface.
> > Segmentation fault
> Hi have you checked whether  the interface-wlan1 is not correct may be
> wlan0 or something else ?
> >
> > My hostapd.conf looks like:
> >
> > interface=wlan1
> > driver=nl80211
> > bridge=br0
> > hw_mode=g
> > channel=5
> > ssid=VirtualAP
> > auth_algs=1
> > bss=wlan1
> > #bssid=00:22:43:21:82:ad
> >
> > If I don?t add a new interface using iw, I wonder how the hostapd
> creates it. And, in order to function as an AP I also need to configurate the
> following a priori :
> >
> > 1.Assign IP
> > sudo ifconfig wlan1 192.168.1.1
> >
> > 2.Enable forwarding
> >
> > 3.Eenable masquerading
> >
> > By using wiphys this is normally not a problem since I add a wiphy
> before initiating hostapd.
> >
> >
> >
> > Thanks for your response
> >
> > Lorna Glenz.
> >
> >
> >
> >
> > --
> > GRATIS! Movie-FLAT mit ?ber 300 Videos.
> > Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome
> > _______________________________________________
> > ath9k-devel mailing list
> > ath9k-devel at lists.ath9k.org
> > https://lists.ath9k.org/mailman/listinfo/ath9k-devel
> >

-- 
Neu: GMX De-Mail - Einfach wie E-Mail, sicher wie ein Brief!  
Jetzt De-Mail-Adresse reservieren: http://portal.gmx.net/de/go/demail

[ath9k-devel] ath9k: Virtual interface as AP

[Mohammed Shafi]

2010/10/27 "Lorna Gonz?lez" <lorna.glez@gmx.net>:
>
> Hi Mr. Shafi,
>
> I am using wlan0 as a station interface but yes, I already tried to use it as AP and wlan1 as station but acording to
> # hostapd will generate BSSID mask based on the BSSIDs that are
> # configured. hostapd will verify that dev_addr & MASK == dev_addr.
>
> hostapd changed the BSSID without succesfull.
>
> So it does not work either.
>
> Thanks
got no idea why its not working.
>
>
> -------- Original-Nachricht --------
>> Datum: Wed, 27 Oct 2010 19:54:39 +0530
>> Von: Mohammed Shafi <shafi.wireless@gmail.com>
>> An: "Lorna Gonz?lez" <lorna.glez@gmx.net>
>> CC: ath9k-devel-request at lists.ath9k.org, ath9k-devel at lists.ath9k.org
>> Betreff: Re: [ath9k-devel] ath9k: Virtual interface as AP
>
>> 2010/10/27 "Lorna Gonz?lez" <lorna.glez@gmx.net>:
>> >
>> > Thanks Mr. Malinen for your reply. I tried to add my interface using
>> hostapd but I get following:
>> >
>> > Configuration file: hostapd.conf
>> > ioctl[SIOCGIFFLAGS]: No such device
>> > Could not read interface flags (wlan1)
>> > nl80211 driver initialization failed.
>> > wlan1: Unable to setup interface.
>> > Segmentation fault
>> Hi have you checked whether ?the interface-wlan1 is not correct may be
>> wlan0 or something else ?
>> >
>> > My hostapd.conf looks like:
>> >
>> > interface=wlan1
>> > driver=nl80211
>> > bridge=br0
>> > hw_mode=g
>> > channel=5
>> > ssid=VirtualAP
>> > auth_algs=1
>> > bss=wlan1
>> > #bssid=00:22:43:21:82:ad
>> >
>> > If I don?t add a new interface using iw, I wonder how the hostapd
>> creates it. And, in order to function as an AP I also need to configurate the
>> following a priori :
>> >
>> > 1.Assign IP
>> > sudo ifconfig wlan1 192.168.1.1
>> >
>> > 2.Enable forwarding
>> >
>> > 3.Eenable masquerading
>> >
>> > By using wiphys this is normally not a problem since I add a wiphy
>> before initiating hostapd.
>> >
>> >
>> >
>> > Thanks for your response
>> >
>> > Lorna Glenz.
>> >
>> >
>> >
>> >
>> > --
>> > GRATIS! Movie-FLAT mit ?ber 300 Videos.
>> > Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome
>> > _______________________________________________
>> > ath9k-devel mailing list
>> > ath9k-devel at lists.ath9k.org
>> > https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>> >
>
> --
> Neu: GMX De-Mail - Einfach wie E-Mail, sicher wie ein Brief!
> Jetzt De-Mail-Adresse reservieren: http://portal.gmx.net/de/go/demail
>

[ath9k-devel] ath9k: Virtual interface as AP

[Peter Stuge]

"Lorna Gonz?lez" wrote:
> I tried to add my interface using hostapd but I get following:
> 
> Configuration file: hostapd.conf
> ioctl[SIOCGIFFLAGS]: No such device

What is the output from:

iw dev

or in case you do not have the iw tool, then from:

iwconfig


//Peter

[ath9k-devel] ath9k: Virtual interface as AP

[Jouni Malinen]

On Wed, 2010-10-27 at 07:11 -0700, "Lorna Gonz?lez" wrote:
> Configuration file: hostapd.conf
> ioctl[SIOCGIFFLAGS]: No such device
> Could not read interface flags (wlan1)
> nl80211 driver initialization failed.

That sounds like you did not have wlan1 when starting hostapd..

> interface=wlan1
> bss=wlan1

This is not a valid configuration. interface defines the main AP
interface and bss is a virtual, secondary interface that will be
created. As such, it must have a different interface name. I was
assuming that you are trying to use multiple AP interfaces, but that may
not be the case.

> If I don?t add a new interface using iw, I wonder how the hostapd creates it. And, in order to function as an AP I also need to configurate the following a priori :

hostapd does not create the main interface; it only configures the
secondary ones (bss=). What you seem to be trying to do (station + AP)
is not really supported that well currently. In theory, you would need
to create a new vif manually (e.g., with iw) and then run hostapd on one
of the interfaces. However, I would not give any guarantees on that
working correctly in all (or well, even most) cases.

- Jouni

[ath9k-devel] ath9k: Virtual interface as AP

["Lorna González"]

Hallo Jouni, 


> > Configuration file: hostapd.conf
> > ioctl[SIOCGIFFLAGS]: No such device
> > Could not read interface flags (wlan1)
> > nl80211 driver initialization failed.
> 
> That sounds like you did not have wlan1 when starting hostapd..
> 
> > interface=wlan1
> > bss=wlan1
> 
> This is not a valid configuration. interface defines the main AP
> interface and bss is a virtual, secondary interface that will be
> created. As such, it must have a different interface name. I was
> assuming that you are trying to use multiple AP interfaces, but that may
> not be the case.
> 
> > If I don?t add a new interface using iw, I wonder how the hostapd
> creates it. And, in order to function as an AP I also need to configurate the
> following a priori :
> 
> hostapd does not create the main interface; it only configures the
> secondary ones (bss=). What you seem to be trying to do (station + AP)
> is not really supported that well currently. In theory, you would need
> to create a new vif manually (e.g., with iw) and then run hostapd on one
> of the interfaces. However, I would not give any guarantees on that
> working correctly in all (or well, even most) cases.
> 
> - Jouni
> 

Your last comment explains exactly what I am trying to do:  STA + AP interfaces on the same radio. That?s why I was setting first a second interface in master mode using iw, which works ok. But after initiated hostapd, other stations are not able to sense this virtual AP. I will try again, otherwise I will keep testing using wiphys. 

thanks again!!

Lorna


-- 
GMX DSL Doppel-Flat ab 19,99 €/mtl.! Jetzt auch mit 
gratis Notebook-Flat! http://portal.gmx.net/de/go/dsl

[ath9k-devel] ath9k: Virtual interface as AP

[jean-pierre cartal]

  Le 27/10/2010 18:32, "Lorna Gonz?lez" a ?crit :
> Hallo Jouni,
>
>
>>> Configuration file: hostapd.conf
>>> ioctl[SIOCGIFFLAGS]: No such device
>>> Could not read interface flags (wlan1)
>>> nl80211 driver initialization failed.
>> That sounds like you did not have wlan1 when starting hostapd..
>>
>>> interface=wlan1
>>> bss=wlan1
>> This is not a valid configuration. interface defines the main AP
>> interface and bss is a virtual, secondary interface that will be
>> created. As such, it must have a different interface name. I was
>> assuming that you are trying to use multiple AP interfaces, but that may
>> not be the case.
>>
>>> If I don?t add a new interface using iw, I wonder how the hostapd
>> creates it. And, in order to function as an AP I also need to configurate the
>> following a priori :
>>
>> hostapd does not create the main interface; it only configures the
>> secondary ones (bss=). What you seem to be trying to do (station + AP)
>> is not really supported that well currently. In theory, you would need
>> to create a new vif manually (e.g., with iw) and then run hostapd on one
>> of the interfaces. However, I would not give any guarantees on that
>> working correctly in all (or well, even most) cases.
>>
>> - Jouni
>>
> Your last comment explains exactly what I am trying to do:  STA + AP interfaces on the same radio. That?s why I was setting first a second interface in master mode using iw, which works ok. But after initiated hostapd, other stations are not able to sense this virtual AP. I will try again, otherwise I will keep testing using wiphys.
>
> thanks again!!
>
> Lorna
>
>
Hi Lorna,

Try starting hostapd before the client side i.e. wpa_supplicant.

Regards.

[ath9k-devel] ath9k: Virtual interface as AP

["Lorna González"]

Hello,

After trying to build two virtual interfaces, one as a STA and another one as AP on mac80211 with an AR928X, creating a new interface with:

iw phy phy0 interface add wlan1 type __ap

I got a new interface called wlan1_rename, the one I used to build the AP interface.

Running hostapd I finally got following: 

Configuration file: hostapd.conf
Opening raw packet socket for ifindex -1215975436
BSS count 1, BSSID mask ff:ff:ff:ff:ff:ff (0 bits)
SIOCGIWRANGE: WE(compiled)=22 WE(source)=21 enc_capa=0xf
nl80211: Added 802.11b mode based on 802.11g information
Allowed channel: mode=1 chan=1 freq=2412 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=2 freq=2417 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=3 freq=2422 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=4 freq=2427 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=5 freq=2432 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=6 freq=2437 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=7 freq=2442 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=8 freq=2447 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=9 freq=2452 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=10 freq=2457 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=11 freq=2462 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=1 freq=2412 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=2 freq=2417 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=3 freq=2422 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=4 freq=2427 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=5 freq=2432 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=6 freq=2437 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=7 freq=2442 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=8 freq=2447 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=9 freq=2452 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=10 freq=2457 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=11 freq=2462 MHz max_tx_power=20 dBm
RATE[0] rate=10 flags=0x2
RATE[1] rate=20 flags=0x6
RATE[2] rate=55 flags=0x6
RATE[3] rate=110 flags=0x6
RATE[4] rate=60 flags=0x0
RATE[5] rate=90 flags=0x0
RATE[6] rate=120 flags=0x0
RATE[7] rate=180 flags=0x0
RATE[8] rate=240 flags=0x0
RATE[9] rate=360 flags=0x0
RATE[10] rate=480 flags=0x0
RATE[11] rate=540 flags=0x0
Passive scanning not supported
Flushing old station entries
Deauthenticate all stations
Mode: IEEE 802.11g  Channel: 5  Frequency: 2432 MHz
Using interface wlan1_rename with hwaddr 00:22:43:21:82:ad and ssid 'VirtualAP'
wlan1_rename: Setup of interface done.
MGMT (TX callback) ACK


But no other stations are able to see this Virtual AP and no more frames are sent from the VAP. 

If someone ever try something similar please let me know. 

Thanks 

Lorna  




-- 
GRATIS! Movie-FLAT mit ?ber 300 Videos. 
Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome

[ath9k-devel] ath9k: Virtual interface as AP

[Jouni Malinen]

On Thu, 2010-10-28 at 00:47 -0700, "Lorna Gonz?lez" wrote:
> After trying to build two virtual interfaces, one as a STA and another one as AP on mac80211 with an AR928X, creating a new interface with:
> 
> iw phy phy0 interface add wlan1 type __ap
> 
> I got a new interface called wlan1_rename, the one I used to build the AP interface.

> But no other stations are able to see this Virtual AP and no more frames are sent from the VAP. 

How did you set the MAC addresses on the interfaces? Based on a quick
test, I was able to get hostapd running on the interface created with
the command above at least when not changing the address on the created
interface. A station was able to see the AP and associate. Then I
changed the MAC address of the original interface by setting locally
administered bit (02:<rest of addr>) and I was able to associate it as a
station to an AP that was running on the same channel. The ping from the
virtual AP interface was still going through.

Just keep in mind that not all combinations will work as far as key
setup is concerned. In other words, you may be able to get associated
with multiple interfaces, but the data frames may not get through if the
driver is not yet ready to the setup you tested. These will be
eventually addressed for most cases, but for now, you may also want to
experiment with nohwcrypt=1 if you see something that could be caused by
this.

- Jouni

[ath9k-devel] ath9k: Virtual interface as AP

["Lorna González"]

Hallo Jouni,

Thanks for taking the time to test my question. I made what you said and it also works, why is it that the VAP should be initialize at first? 
I will try its performance, if someone is interested in results let me know

Regards

Lorna  
-- 
GMX DSL Doppel-Flat ab 19,99 €/mtl.! Jetzt auch mit 
gratis Notebook-Flat! http://portal.gmx.net/de/go/dsl

[ath9k-devel] ath9k: Virtual interface as AP

["Lorna González"]

Hello 

I finally got a station an a virtual AP working on the same channel using the setup below. I made some test sending TCP through iperf between the AP and the station and the VAP to a station associated with it. 
Using an AP operating with Ieee802.11n, an atheros AR928X and without virtual interfaces I get a max throughput of 50 MBits/s. 
As soon as I start using my desired setup, the thoughput of the station is about 15 MBits/s... I actually need to make the rate fixed using iwconfig to get this max. Otherwise the traffic is sent at 1 MBit/s.

Can someone please tell me how is the behaviour of the rate control in case of virtual interfaces on mac80211?

Thanks in advanced

Lorna Gonz?lez. 



-------- Original-Nachricht --------
> Datum: Thu, 28 Oct 2010 11:03:47 +0300
> Von: Jouni Malinen <jouni.malinen@atheros.com>
> An: "\\"Lorna Gonz?lez"" <lorna.glez@gmx.net>
> CC: "ath9k-devel at lists.ath9k.org" <ath9k-devel@lists.ath9k.org>
> Betreff: Re: [ath9k-devel] ath9k: Virtual interface as AP

> On Thu, 2010-10-28 at 00:47 -0700, "Lorna Gonz?lez" wrote:
> > After trying to build two virtual interfaces, one as a STA and another
> one as AP on mac80211 with an AR928X, creating a new interface with:
> > 
> > iw phy phy0 interface add wlan1 type __ap
> > 
> > I got a new interface called wlan1_rename, the one I used to build the
> AP interface.
> 
> > But no other stations are able to see this Virtual AP and no more frames
> are sent from the VAP. 
> 
> How did you set the MAC addresses on the interfaces? Based on a quick
> test, I was able to get hostapd running on the interface created with
> the command above at least when not changing the address on the created
> interface. A station was able to see the AP and associate. Then I
> changed the MAC address of the original interface by setting locally
> administered bit (02:<rest of addr>) and I was able to associate it as a
> station to an AP that was running on the same channel. The ping from the
> virtual AP interface was still going through.
> 
> Just keep in mind that not all combinations will work as far as key
> setup is concerned. In other words, you may be able to get associated
> with multiple interfaces, but the data frames may not get through if the
> driver is not yet ready to the setup you tested. These will be
> eventually addressed for most cases, but for now, you may also want to
> experiment with nohwcrypt=1 if you see something that could be caused by
> this.
> 
> - Jouni
> 
> 

-- 
GMX DSL Doppel-Flat ab 19,99 &euro;/mtl.! Jetzt auch mit 
gratis Notebook-Flat! http://portal.gmx.net/de/go/dsl

[ath9k-devel] ath9k: Virtual interface as AP

[Ben Greear]

On 11/11/2010 07:06 AM, "Lorna Gonz?lez" wrote:
>
> Hello
>
> I finally got a station an a virtual AP working on the same channel using the setup below. I made some test sending TCP through iperf between the AP and the station and the VAP to a station associated with it.
> Using an AP operating with Ieee802.11n, an atheros AR928X and without virtual interfaces I get a max throughput of 50 MBits/s.
> As soon as I start using my desired setup, the thoughput of the station is about 15 MBits/s... I actually need to make the rate fixed using iwconfig to get this max. Otherwise the traffic is sent at 1 MBit/s.
>
> Can someone please tell me how is the behaviour of the rate control in case of virtual interfaces on mac80211?

Can you give a more detailed description/diagram of your virtual AP setup and
network throughput test?  It sounds like you are using the same radio as AP
and STA?  If so, then of course you are going to get less bandwidth on the
VIFS because they have to share the radio.

I'm not sure it should drop all the way to 15Mbps, though.  We haven't done a lot of throughput
testing yet, but if we use two STA vifs on the ath9k box connected to an 80211n AP (trendnet),
then we can set a max of about 9Mbps tx + rx across each STA (the STAs are sending to each other).
That is around 40Mbps total tx + rx across the radio.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com

[ath9k-devel] ath9k: Virtual interface as AP

["Lorna González"]

Hi Ben, 

My scenario looks like this: 
wlan0 operates as an AP using hostapd and it is associated to aclient 
a wlan1 virtual interface is in managed mode and associated to an Ieee 802.11n AP. 
They share the same channel. 
When I measure the throughput with TCP streams in jperf I get following:

[ath9k-devel] ath9k: Virtual interface as AP

[Ben Greear]

On 11/12/2010 01:21 AM, "Lorna Gonz?lez" wrote:
>
> Hi Ben,
>
> My scenario looks like this:
> wlan0 operates as an AP using hostapd and it is associated to aclient
> a wlan1 virtual interface is in managed mode and associated to an Ieee 802.11n AP.
> They share the same channel.
> When I measure the throughput with TCP streams in jperf I get following:
>> From wlan1 to the AP = 14,4 MBits/s
>> From wlan0 to the AP = 8 MBits/s (wlan0 is far away from the VAP and AP)
> Both sending traffic at the same time:
>> From wlan1 to the AP = 12 MBits/s
>> From wlan0 to the AP = 1,6 MBits/s (?)

I'm perhaps not thinking well this morning, but I am having trouble
understanding your network.

Can you please draw an ascii or other form of diagram?

Thanks,
Ben

>
> Like you said, it is low because both interfaces share the medium but if I don?t change the rate using iwconfig, this values or at least the first one goes down until 1,5 MBits. That?s way I wonder if there is something that keeps the rate low by the time a virtual interface is created.
>
> Thanks for your response
>
> Best regards
>
> Lorna
>
>
> -------- Original-Nachricht --------
>> Datum: Thu, 11 Nov 2010 09:00:45 -0800
>> Von: Ben Greear<greearb@candelatech.com>
>> An: "Lorna Gonz?lez"<lorna.glez@gmx.net>
>> CC: Jouni Malinen<jouni.malinen@atheros.com>, ath9k-devel at venema.h4ckr.net
>> Betreff: Re: [ath9k-devel] ath9k: Virtual interface as AP
>
>> On 11/11/2010 07:06 AM, "Lorna Gonz?lez" wrote:
>>>
>>> Hello
>>>
>>> I finally got a station an a virtual AP working on the same channel
>> using the setup below. I made some test sending TCP through iperf between the
>> AP and the station and the VAP to a station associated with it.
>>> Using an AP operating with Ieee802.11n, an atheros AR928X and without
>> virtual interfaces I get a max throughput of 50 MBits/s.
>>> As soon as I start using my desired setup, the thoughput of the station
>> is about 15 MBits/s... I actually need to make the rate fixed using
>> iwconfig to get this max. Otherwise the traffic is sent at 1 MBit/s.
>>>
>>> Can someone please tell me how is the behaviour of the rate control in
>> case of virtual interfaces on mac80211?
>>
>> Can you give a more detailed description/diagram of your virtual AP setup
>> and
>> network throughput test?  It sounds like you are using the same radio as
>> AP
>> and STA?  If so, then of course you are going to get less bandwidth on the
>> VIFS because they have to share the radio.
>>
>> I'm not sure it should drop all the way to 15Mbps, though.  We haven't
>> done a lot of throughput
>> testing yet, but if we use two STA vifs on the ath9k box connected to an
>> 80211n AP (trendnet),
>> then we can set a max of about 9Mbps tx + rx across each STA (the STAs are
>> sending to each other).
>> That is around 40Mbps total tx + rx across the radio.
>>
>> Thanks,
>> Ben
>>
>> --
>> Ben Greear<greearb@candelatech.com>
>> Candela Technologies Inc  http://www.candelatech.com
>>
>


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com