Multicast traffic over mesh network

[Francesco]

Andrey,
actually i am using ath5k drivers,on atheros AR5414 (802.11 a/b/g) devices.
OS is ubuntu linux or OpenWrt, depends on machine type.

Mmh... I'll be more precise on the test i am running:
i am trying to stream multicast video content via VLC software.
All mesh nodes has assigned 192.168.3.xxx address.
One node is kept out the mesh as monitor.

To stream the content, multicast ip address is set in VLC on the server
machine 239.255.12.42:5000
Other clients to get the video simply launch vlc, open network resource at
udp://239.255.12.42:5000

This procedure actually works on the ethernet.

If i route the traffic over the mesh interface (from server I add route
239.255.0.0 to mesh interface) i get the network to lose a big amount of
data, i can see that the interfaces set their transmit speed to 1 Mbps
sniffing any data frame.
VLC log tells me that the network is losing packet (cannot sync to video
stream) and i get no vid on the clients.

Thing works different if I send unicast data from the server machine to
ather client on the mesh.
I got up to four unicast streams across the mesh to four different client
with 2 hop distance from server work flawlessy.No data loss, perfect video
streaming.
Sniffig data frame (but also if I fire $ iw dev mesh station dump) shows
link speed above 24Mbps.
So there's something wrong with multicast..

Andrey which kind of multicast traffic have you been sending on the mesh?

maybe i've got something misconfigured. I'll check tomorrow.
Any hit more than welcome :)))





On Mon, Mar 16, 2009 at 6:11 PM, Andrey Yurovsky <andrey at cozybit.com> wrote:

> Interesting.  I've tested multicast over mesh and it worked (using
> ath5k and b43).  Which drivers are you using?
>
> 2009/3/16 Francesco <francesco.cappuccio at gmail.com>:
> > Hi,
> > did anyone succeed in multicast transmission over mesh?
> >
> > Actually I am streaming multimedia content from my laptop, and i sniff
> > correctly routed traffic on the mesh, but for some reason i am not fully
> > understanding, other nodes on the mesh do not receive multicast traffic
> as
> > they sould.
> > It seems to me that all nodes correctly forward frames inside the mesh,
> but
> > data contained in each frame do not reach application level...
> >
> > All works like a charm if  I unicast the stream to any IP on the mesh...
> >
> > --
> > Francesco Cappuccio
> >
> >
> > _______________________________________________
> > Devel mailing list
> > Devel at lists.open80211s.org
> > http://open80211s.com/mailman/listinfo/devel
> >
> >
>
>
>
> --
> Andrey Yurovsky
> cozybit Inc.
> _______________________________________________
> Devel mailing list
> Devel at lists.open80211s.org
> http://open80211s.com/mailman/listinfo/devel
>



-- 
Francesco Cappuccio
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://open80211s.com/pipermail/devel/attachments/20090316/5dc15218/attachment.html