On Jun 13, 2011, at 12:50 PM, Ricky Beam wrote: > On Sun, 12 Jun 2011 09:45:01 -0400, Leo Bicknell <bickn...@ufp.org> wrote: >> In a message written on Sun, Jun 12, 2011 at 01:04:41PM +0200, Iljitsch van >> Beijnum wrote: >>> Like I said before, that would pollute the network with many multicasts >>> which can seriously degrade wifi performance. >> >> Huh? This is no worse than IPv4 where a host comes up and sends a >> subnet-broadcast to get DHCP. > > Broadcast != Multicast. esp. when talking about wireless chipsets. I've yet > to find a wifi chipset that didn't completely fuck-up when presented with > even a low pps of multicast traffic. Broadcast traffic doesn't seem to > bother them -- it doesn't attempt to filter them in any way, or really pay > them any attention. If I had to guess, the chip firmware is individually > transmitting multicast packets to each peer; a broadcast packet is sent once > to all peers. > > I've not had any wireless networks disrupted by broadcast traffic -- and with > Radware load balancers in the network, there are *plenty* of broadcasts > (ARP). Just a few 100pps of multicast and the AP fails. (linksys, netgear, > even cisco... all broadcom crap radios.) > > --Ricky
You would need an AWFUL lot of hosts for this to add up to a few 100pps (or even 10pps) of multicast traffic. Owen
