Hello zb1981gm (btw, do you have a real name?),

On Tue, Dec 06, 2011 at 05:01:13PM +0800, zb1981gm wrote:

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

What is batman version 2.0? We have batmand (layer 3), but I guess you are using batman advanced as you talk about bonding/interface alternating later. These have 0.X (for old releases) or 201X.Y.Z version schemes (since 2 years). Please clarify.

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

Have you compared this to static routing?

So the conclution is that the bandwidth will be halfed with the 1 hop increase! right?

It should not, as different radio modules are used (and correctly tuned on different channels). However, you may have a limitation in your CPU power or something else. You may want to try static routing to find this out.

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

To make bonding work, there are a few conditions: * routers must be equipped with multiple radios which can connect to each other * activate bonding (batctl bonding 1) * make sure the transmit qualities are similar (check with batctl o), should not be more than a difference of 50

If everything is fine, you can get a boost of approx. 50%.

According to the batman official site, alternating or bonding mode would improve the performance compared with the single radio mode

Yup, it should help. Alternating is not helping in your scenario as far as I understand (your mesh is only 1 hop long, as notebooks are connected via infrastructure mode). Bonding may help as described above.

best regards, Simon