On Sun, Jul 29, 2012 at 6:43 PM, Yeoh Chun-Yeow <[email protected]> wrote: > Hi, Putri > > In addition to this, the number of broadcast beacon frame has also > increased once the number of devices are increased. This also could > lead to more frame collision.
Well noted but I believe the main factor should be the multicast retransmissions: beacons occur N per beacon interval (default 1 sec), while multicast frame retransmissions will occur N per frame (N being the number of nodes in range). Cheers, Javier > Regards, > Chun-Yeow > > On Mon, Jul 30, 2012 at 9:25 AM, Javier Cardona <[email protected]> wrote: >> Hi Putri, >> >> On Sun, Jul 29, 2012 at 6:17 PM, put <[email protected]> wrote: >>> I have implemented the patch for increasing the multicast rate (from git: >>> {nl,cfg,mac}80211: Allow Setting Multicast Rate in Mesh). >>> >>> >>> While testing using iperf, I found out that: >>> >>> >>> 1. When there are only 2 mesh devices (1 is the multicast server and the >>> other is the client) in the network, I can get up to 14Mbps if the >>> mcast-rate is configured to 54Mbps. >>> >>> 2. I then added another mesh device on to the network (multicast rate set to >>> 54Mbps also). But this mesh device is not sending any multicast packet to >>> the server. The rate I observed was 10Mbps between the 2 mesh devices above >>> in 1. >>> >>> 3. I proceeded to add the 4th mesh device (also multicast rate set to >>> 54Mbps, and not sending multicast packet to the server), observed rate >>> dropped to 8Mbps between the server and the single client. >>> >>> >>> Is this expected? Why does the presence of other mesh devices in the network >>> (even though not sending multicast packet) affects the rate between the >>> server and client? >> >> Multicast dissemination in o11s is implemented via controlled >> flooding. This means that each mesh node will retransmit each >> multicast frame exactly once. Hence, an increase in the number of devices >> in the network will result in an increase of retransmissions. >> >> Cheers, >> >> Javier >> >> >> >> -- >> Javier Cardona >> cozybit Inc. >> http://www.cozybit.com >> _______________________________________________ >> Devel mailing list >> [email protected] >> http://lists.open80211s.org/cgi-bin/mailman/listinfo/devel > _______________________________________________ > Devel mailing list > [email protected] > http://lists.open80211s.org/cgi-bin/mailman/listinfo/devel -- Javier Cardona cozybit Inc. http://www.cozybit.com _______________________________________________ Devel mailing list [email protected] http://lists.open80211s.org/cgi-bin/mailman/listinfo/devel
