> There is a spec for echo cancellation on PSTN called g.168. I believe > it's a > suite of tests which put the echo canceller through its paces and if you > pass > them you are certified to conform to g.168. None of the echo cancellers in > zaptel conform to this, whereas the Octasic, Tellabs and other hardware > echo > cancellers all do. If someone were to put the effort and energy into > making > the software echo cancellers compliant, you should find similar results to > the hardware echo cans.
Just out of curiosity, what form does the testing take? Is it simply a set of audio sample pairs (outbound, and inbound with some echo of outbound) that you run the ec against and the measure the results? What metrics are measured? I can only think of: . the amount of echo left after the ec has run . training time How hard would it be to make a g.168 test bed that the Asterisk ec's could be run against? I can definitely see the value in even just making some audio samples for people to listen to and giving each ec (with version number and tunable parameter values) a score against each sample, even if it's just a subjective score based on perception from users. That way a newbie could listen to the audio samples to find one that sounds like the sort of echo they are getting (mainly based on delay I guess but different types of echo will have different frequency responses than others) and then can pick a good ec based on score. Comments? James _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
