Michaelwagner Wrote: > > > Across a hub, propegation is essentially instantaneous. > > Across a switch, there is a very tiny delay and the potential of a > longer one if there is interfering traffic on the other side of the > switch. I don't know if there is a promise by the protocol to limit the > delay to a level where it would be insignificant for this use. > > Across a wireless access point? I expect all bets are off. I'm not sure > multicast will offer any advantages there ...
You need to reconsider your definition of instantaneous. :) Sound only travels at measely 1.1 feet per millisecond, so even if your synchronization were "only" accurate to within a millisecond, you would still be synced to just a small fraction of the distance between your speakers. The thing is NTP can even do a lot better than 1ms... how accurate you can get is mostly a function of variance over long periods time in the latency of the network/OS (and this is very low for Squeezeboxes on a wireless lan), NOT the absolute timing between hosts. i.e. it doesn't matter if one machine is directly connected and the other is on wireless, you can compensate for this with a high degree of accuracy, provided you can make reasonable assumptions about the latency being consistent and symmetric for trasmit vs receive (which lucky for us it is). When you consider the speed of sound (30,000 uS between rooms) vs the speed of 802.11g (600 uS to go the same distance) it makes sense that even our simple "go now!" signal should work in most cases (usually within 2-5ms). But with NTP (or similar protocol) it could be a lot more accurate, and there are other sync improvements that would be possible once a solid continuous time base is available, eg using multicast to save bandwidth, and drifting instead of rebuffering to align clocks. -- seanadams ------------------------------------------------------------------------ seanadams's Profile: http://forums.slimdevices.com/member.php?userid=3 View this thread: http://forums.slimdevices.com/showthread.php?t=19466 _______________________________________________ Discuss mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/discuss
