On Sunday 12 October 2008 04:15:02 Olivier wrote: > 2008/10/11 Eric ManxPower Wieling <[EMAIL PROTECTED]> > > > Handsets use a 4-wire connection. Handsets with the the volume turned > > up could cause a form of echo as the microphone picks up the ear piece > > audio (I call this acoustic echo). Everything I said applies to 2-wire > > caused echo. Other types of echo is fairly uncommon and cannot be > > solved by normal echo canceling systems. > > > > Most echo canceling systems I've seen (mostly tellabs) only cancel echo > > in one direction. > > Which one ? > Using previous example, I would say they cancel Bob's voice echo ... > Said differently, echo canceller would filters out from outgoing audio > signals matching signals previously heard in incoming audio (Bob's voice). > > > I suspect all of Digium's EC systems only do echo > > canceling in one direction as well. > > Is anyone aware of EC systems working in both directions ?
Pray tell, how do you echo cancel in both directions? Wouldn't that necessitate cancelling echo before it occurs on the line (sort of a white noise/pink noise kind of operation)? Seems like modelling a projectile such that when it reaches its target, the atmospheric stresses during its flight turn it into a perfect sphere (and with about the same likelihood of success). -- Tilghman _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users