Re: [B.A.T.M.A.N.] Network Coding testing.

["Martin Hundebøll" <martin@hundeboll.net>]

Hi Ajeet,

On 2013-09-12 15:36, ajeet singh wrote:
> I am trying to test network coding functionality of batman-adv. I am
> facing some problems.
>
> Please find my topology information,
>
> I created network with three nodes ( ad-hoc),
>
> Node A --- Node B --- Node C
>
> I did following settings,
>
> --- Complied latest batman-adv. with NC enabled.
> --- I did all setting form
> http://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding
> --- Kept all nodes in promiscuous mode. (Nodes are working properly in
> this mode).
>
> When I started iperf (TCP) from node A to node C, Node B stopped
> responding after few seconds. B is not sending OGM to A and C.
>
> When I tested without NC everything work fine.
>
> Is there any additional settings required for NC test?

As we figured out on IRC, the problems were caused by the ath9k_htc 
chip/driver, which does not handle packet sizes larger than 1500 bytes 
that well. So changing the MTU of your bat0 interface to something like 
1480 solved the problem.

It is a bit weird though, cause my personal experience says that 
ath9k_htc can handle packets up to 1550 bytes, which batman-adv+NC 
shouldn't exceed. Maybe a quick inspection with tcpdump/wireshark can 
give us some numbers?

// Martin

-- 
Kind Regards
Martin Hundebøll
Frederiks Allé 99, 1.th
8000 Aarhus C
Denmark

+45 61 65 54 61
martin@hundeboll.net