Mac Level Handoffs

[Craig Thornton]

Hi,

If you put both AP's in "AP mode" with the same essid (iwconfig will 
say Master mode), bridge the wlan0 and eth0 interfaces together on each 
of them, and then plug them into the same Ethernet segment, your FTP 
connection will be persistent.  MAC layer handoffs will take place in 
this setup.

I do not understand why you have configured a machine running in 
Managed mode as a bridge.  The bridging should take place on the 
machines that are configured as AP's and hence are in Master mode.  
btw. bridging a managed interface typically does not work very well 
with kernel bridging.

Craig





On 4-Jan-04, at 3:31 PM, Anand S. Katti wrote:

> Mr. Craig,
>
> Thanks a lot for your input.
>
> I had the following setup.
>
> HOSTAP--------DLINK-AP_DWL900+
>
> Dlink is on a ethernet. And HOSTAP is also on the SAME LAN.
> With the help from Mr.Patrick Tran, i got to know how to configure the 
> machine
> as bridge with hostap running in Managed mode.
>
> Then I started Dlink also in AP mode 5 channels apart from hostap.
> And i gave the same ssid to both the AP's.
>
> The Above setup says that Both the AP's are in AP MODE.
>
> Am I right ?
>
> What should i do , if i use both AP's of DLINK.  If I just put both the
> AP's in AP mode with same ssid, and plug them in Ethernet, will they 
> work
> ? in giving persistent connection ?
> Will the MAC level hand off's still takes place ?
>
>
>
>
>>
>> In your setup your FTP session will be persistent if both of your AP's
>> are configured as bridges.
>>
>> It is ok for the hostap interface (wlan0) to be in Master mode as they
>> will be acting as AP's and sending out beacons.  In fact I would
>> recommend that you stick to Master mode in this setup.  The difference
>> in channels will not matter either.  It may however increase your
>> handoff latency slightly but FTP is not delay sensitive so you should
>> be ok.  Typical handoff delays are 250 to 750 ms.
>>
>> In order to configure a your AP as a bridge simply use kernel bridging
>> and put both wlan0 and eth0 into your newly created bridge group.
>>
>> All 802.11 handoffs are MAC layer handoffs.  Anything above L2 will be
>> independent of hostap.
>>
>> I hope that this helps you out.
>>
>> Cheers,
>>
>> Craig
>>
>> Date: Sat, 3 Jan 2004 21:49:39 +0530 (IST)
>> From: "Anand S. Katti" <askatti at ece.iisc.ernet.in>
>> Subject: Mac Level Handoffs
>> To: hostap at shmoo.com
>> Message-ID: <Pine.BSF.4.58.0401032142020.55152 at ece.iisc.ernet.in>
>> Content-Type: TEXT/PLAIN; charset=US-ASCII
>>
>> Hello All,
>>
>> I got one more query for HOTSPOT.
>>
>> I am setting up a HOTSPOT, but im understanding how things work at 
>> this
>> point..
>>
>> hostap1----------------------hostap2
>>
>> hostap1:
>> channel 1
>> ssid=test
>>
>> hostap2
>> channel 6
>> ssid=test
>>
>> Both hostap are operating in AP mode.
>>
>> If I with a LAPTOP with an FTP session ON from hostap1 towards hostap2
>> then will this session get disconnected ? or it will be on even on
>> hostap2
>> area? Will the connection be persistent?
>>
>> As requirement i'll seperate both AP's with 5 channels apart.
>>
>> Will the above setup work ? if not why ? I think essentially im asking
>> whether above setup leads to MAC LEVEL HANDOFF's?
>>
>> Should the hostap2 be in repeater/BRIDGE mode ?
>>
>> Kindly showme the way.
>> Anand S.Katti
>>
>