[ath9k-devel] ath9k: Virtual interface as AP

[Ben Greear <greearb@candelatech.com>]

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