This is indeed an excellent paper. And I learned something I didnt know, and it may clear things up to people who dont have the time to read the whole article:
"The role of the echo canceler is to remove the echo portion of the signal coming out of the tail circuit and headed into the WAN" I point this out because I thought that the function of echo cancelation was the oposite (remove echo coming in). Also from this paper, if you want to test if echo cancellation is working at the other end: "The quickest way to determine if you have a working echo canceler in the circuit is to make a call and immediately begin to say something like "TAH TAH FISH" repeatedly. The person on the other end of the line should be silent. If you are calling a voice-mail system, wait for the announcer to stop talking before starting the experiment. If the terminating tail circuit has cancelable echos and if the echo canceler is enabled, you will hear echo for the first few utterances and then it will die away. After a few seconds of speech, the echo should be gone or at least very quiet compared to the echo level at the beginning of the call. This is the signature of a working echo canceler. " This really is a great article, and everyone having echo issues should read it. Thanks Richard! ----- Original Message ----- From: "Richard Scobie" <[EMAIL PROTECTED]> > According to the excellent Cisco paper "Echo Analysis for Voice over > IP", which the Wiki links to at: > > http://www.cisco.com/en/US/tech/tk652/tk701/technologies_white_paper09186a00800d6b68.shtml > > > "Headsets are particularly notorious for poor echo performance.". This > is due to lack of acoustic isolation. Perhaps you could test using > headphones and a mic. > > After reading the above paper, I was able to tune my setup and make a > significant improvement. Given the high number of questions about echo > on the list, it would almost be worth including the link to it as a > file, "README.echo" in the source. > > Richard _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
