Linux Ethernet Bridging - Apr 2007 - [Bridge] Bridge Performance 2

Hi there,

I was asking this question already a few days go, but I'm not sure whether
anyone noticed due to the mailserver outtage. So I'm just re-posting it,
sorry, but it's an important issue for me, I would be glad to hear some
insight on this.
 
The question is regarding throughput performance using linux 2.4.5.1. My setup
is very simple : I have two laptops with a wireless card. On each laptop I
configure the wireless cards to be in ad hoc mode, create a bridge and include
the interface within the bridge (stp is off). Then of course I'm assigning
an IP address to the bridge while assigning 0.0.0.0 to the wireless interface
(eth1). After having setup both machines I run throughput tests using iperf.
What I measure is around 1.5 Mbit/s for TCP traffic. This is about 1/3 of what I
get when communicating directly through the wireless interface on both machines,
without any bridge on top. Where all this performance gets lost? Does anyone
have an idea? The same performance degradation I measured on a 2.6 Kernel.
 
Any help would be appreciated.
 
Best Regards, 
Patrick

See the FAQ at http://bridge.sourceforge.net/faq.html for the answer.

-M

On Fri, 3 Dec 2004, Patrick Stuedi wrote:
> Hi there,
>
> I was asking this question already a few days go, but I'm not sure
whether
> anyone noticed due to the mailserver outtage. So I'm just re-posting
it,
> sorry, but it's an important issue for me, I would be glad to hear some
> insight on this. 
> The question is regarding throughput performance using linux 2.4.5.1. My 
> setup is very simple : I have two laptops with a wireless card. On each 
> laptop I configure the wireless cards to be in ad hoc mode, create a bridge
> and include the interface within the bridge (stp is off). Then of course
I'm
> assigning an IP address to the bridge while assigning 0.0.0.0 to the
wireless
> interface (eth1). After having setup both machines I run throughput tests 
> using iperf. What I measure is around 1.5 Mbit/s for TCP traffic. This is 
> about 1/3 of what I get when communicating directly through the wireless 
> interface on both machines, without any bridge on top. Where all this 
> performance gets lost? Does anyone have an idea? The same performance 
> degradation I measured on a 2.6 Kernel.
>
> Any help would be appreciated.
>
> Best Regards, Patrick
>
>
>
-- 

Mark S. Mathews

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