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

["zb1981gm"<zb80211@gmail.com>]

> Hello zb1981gm (btw, do you have a real name?),
I am sorry,you can call me Ice_zheng

> 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. 

It's Batman_adv 2011.2.0

> Have you compared this to static routing?
So, you think the test result is abnormal,right?
As regard to the IP address configuration of routerA and routerB,
I bridge the eth0,wlan0 ,wlan1 all together,so routerA and routerB  has only 1 IP address respectively

                                                     batman
                  channel1                           channel 36                            channel 11
notebook1(wlan0) -------- (wlan0)routerA(wlan1) -------------------- (wlan1)routerB(wlan0)---------- (wlan0)notebook2
10.10.10.1                10.10.10.2                                  10.10.10.3                     10.10.10.4

you suggest static routing,means without batman routing,just use ad-hoc mode,than add static route on each node,right?

notebook1(wlan0)          routerA(wlan0)            routerA(wlan1)            routerB(wlan1)           routerB(wlan0)           notebook2(wlan0) 
10.10.10.1                10.10.10.2                20.20.20.1                20.20.20.2               30.30.30.1               30.30.30.2

then add next hop gateway at each node(route add .....)
that is what you mean?
If no batman routing protocol,It certainly should has a better performance 
actually,my test result shows that(single radio mesh,if relay node are equiped with dual radio worked on interface alternating,it would be better)
if via 1 hop,bandwidth has x
then via 2 hop,bandwidth remain x/2
then via 3 hop,bandwidth remain x/4
.......


> 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 check the cpu(ar7161) loading (using top utility),less than 30% ,memory still remain 16M, so it has nothing to do with cpu loading and memory consumation
As regard to the channel assignment of different wireless card,I still have some puzzle.
I originally think that no interference should be available if radios are configured on non_overlap channel such as 1,6,11.
but,actually not.interference is still available though radios are configured on channel 1 and channel 11
                    channel 1
routerA(wlan0)  ------------------  routerB(wlan0)
                    channel 11
routerA(wlan1)  ------------------  routerB(wlan1)

if start iperf only on wlan0 or wlan1 singlely , bandwidth has 50Mbps almost.
if start 2 iperf simultaneously,both drop sharply

you must think that interference should be absolutely  not available at 2.4g channel and 5g channel.
but still has a little, because I change channel 11 to channel 36,if start 2 iperf simultaneously,bandwidth still drop
when I turn down the txpower of wlan0 or wlan1 ,drop degree would be better.
so channel interference is still a problem,OMHO.But I can't fix that except turn down the txpower.
do you have some advice?
the two radio's antenna distance is about 10cm

by the way, have you ever used the atheros 9220 wireless minipci card,the best bandwidth you have ever test is how much?

the ar9220 wireless card is 802.11n 300Mbps ,so I think 100Mbps should be available at least 

and It looks as if HT40 mode doesn't take effect, performance has almost no difference with HT20 mode

> 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%. 

I promise that all the conditions you mentioned are met.but no boost with bonding 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.

I try the 3 point scene test,alternating did take effect

                 channel1                           channel 36                            channel 11                       channel 36
notebook1(wlan0) -------- (wlan0)routerA(wlan1) -------------------- (wlan1)routerB(wlan0)---------- (wlan0)routerC(wlan1)------------(wlan1)notebook2

routeA-wlan0:AP 
routeA-wlan1:mesh
routerC-wlan1:AP
routerC-wlan0:mesh

notebook1 iperf routerA:40Mbps
routerA iperf routerB:36Mbps
routerB iperf routerC:40Mbps
routerC iperf notebook2:40Mbps

when routerB is configured as single radio for batman
notebook1 iperf routerC : 18Mbps
notebook1 iperf notebook2:9Mbps
when routerB is configured as dual radio work on interface alternaing(2.4g and 5g alternating)
notebook1 iperf routerC : 25Mbps
notebook1 iperf notebook2:9.5Mbps

so my conclution is still that,if batman_adv work on single radio router,bandwidth would be halfed when 1 hop increase,if the relay node equiped with dual radio work on interface alternating,it would be better a little

by the way,I still have another 2 problems,could you give me some advice
1.is there some approach to add static route for batman,configure nexthop forcely ,just ignore the  TQ value,I want to measure the bandwidth performace via wireless hop exactly
2.could you give me some advice about testplan for about 20 nodes mesh network (besides ping,iperf,ftp...).


best regards,
ice_zheng
2011/12/7