> Jack Coates wrote: >> >> Anyway, as others have noted, multicast doesn't like wireless. > > There may be issues with layer 2 ethernet multicast over certain > vendors' APs, but the standard layer 3 routed multicast packets (that > I at least was speaking of?) will work fine regardless of the layer 2 > device underneath.. Wireless won't make a difference as long as the > device is acting as a bridge and not a router. > > -- Mike
Theoretically, you are right. In practice, multicast does not like wireless. Granted, it may be able to struggle along well enough to serve the low-bandwidth needs of a Squeezebox stream, but since there are plenty of people unable to get that working now, I have my doubts. On a side note, try typing "Theory" into Google Earth :) Anyway, multicast (much like Ethernet itself) rather requires that all nodes in the group are able to operate at a lowest common denominator speed. WAPs deal with this situation by either breaking the bus down into bridged zones based on the connection speeds attained by the connected nodes, or by forcing all nodes to the speed attained by the slowest node. Therefore an IP multicast group may contain members who are at 1.1 mbps half-duplex and members who are at 11 mbps half-duplex. A WAP that's bridging into a real Ethernet is even worse, as now the fast end of the pool is 100 Mbps full-duplex. End result is that your entire multicast group bumbles along at 50% of 1.1 mbps in order to cater to the slowest node, who is still complaining mightily that it's going too fast and that he's missing half the packets. By doing unicast streams instead, most nodes perform fine and the slow node is the only one who sucks. Sure, you could write your multicast so that slow complainers get dropped, but why would SDI go to that effort for this application? -- Jack At Monkeynoodle.Org: It's A Scientific Venture... "Believe what you're told; there'd be chaos if everyone thought for themselves." -- Top Dog hotdog stand, Berkeley, CA _______________________________________________ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
