Re: [B.A.T.M.A.N.] about batman performance

Wuchi
2011-12-06T10:23:33Z

Hi zb981gm,

we had a (somewhat) similar performance issue with our setup some time ago. We found out that a setup of two n-Cards in a single room decrease performance heavily, if both cards are under load at the same time. Forcing the cards into b/g mode did not help, so changing the cards to b/g hardware solved the problem for us.

May had to do with those fallback window override issues some n-Cards have, but not sure. In general, don't expect too much of an performance increase with n-Hardware on a USB 2.0 interface.

May be worth a try to look at first before fiddling around with the protocol, IMHO.

- Wuchi

Am 06.12.2011, 10:01 Uhr, schrieb zb1981gm <zb80211@gmail.com>:

> I have used batman on my project for several months.It performs very well,stable especially!
> But,actually,I am not satisfied with the performance of Batman.I found that the bandwidth would drop sharply with the wireless hop increase.
> Now I provide my test result here:
>
> routerA and routerB is composed of compex wp543ahv mainboard (AR7161 platform) and two AR9220 wireless card.Firmware is Openwrt backfire.
> one card is working on 2.4G channel as AP mode,the other is working on 5G channel as mesh backbone
> batman version:2.0
> notebook1 and notebook2 is equiped with 802.11n usb wireless card which access to the AP mode card of routerA and routerB
>
> channel 1 channel 36 channel 11
> notebook1 --------------- routerA -------------- routerB -------------- notebook2
>
> I use iperf to test bandwidth
>
> notebook1 ----------- routerA 45Mbps
> routerA ----------- routerB 46Mbps
> routerB ----------- notebook2 45Mbps
>
> But the bandwidth between notebook1 and notebook2 remains 8Mbps
> bandwidth between notebook1 and routerB remain 18Mbps
>
> So the conclution is that the bandwidth will be halfed with the 1 hop increase! right?
>
> I also found that the interface alternating mode and bonding mode doesn't take effect
>
> channel 1
> routerA ------------------ routerB
> channel 36
>
> The test result is no difference whatever I configured alternating or bonding or just single radio
>
> According to the batman official site, alternating or bonding mode would improve the performance compared with the single radio mode
>
> looking forward somebody's help
> highly appreciated!