Hi: I am working on a new system with a TDM-400P card with three FXO modules and one FXS module.
The system has been in place for a week. Users are complaining of echo problems. I have noticed this echo myself. It varies in severity. It is sometimes bad enough to make it difficult to converse, but the users find it generally unacceptable. They miss their old phones, which just worked. As you can imagine, this is not the way to get them excited about this technology. I have used the 1.4 branch version of fxotune to tune the card. These are the echo statistics I get on the affected channels. > asterisk1 asterisk # fxotune -d -b 1 -w 1004 > Dumping module /dev/zap/1 > echo ratio = 0.0077 (85.5 / 11145.0) > Done! > asterisk1 asterisk # fxotune -d -b 3 -w 1004 > Dumping module /dev/zap/3 > echo ratio = 0.0296 (330.2 / 11145.0) > Done! According to the wiki, both those echo ratios should be more than sufficient to let the echo canceller handle the echo. Residual echo is present, however. It doesn't interfere with conversation, but I could see how it would be irritating, especially if you never had it before. The call experience should get better, rather than worse -- especially if we're using Polycom IP 650s. Questions: - What settings might I tweak to eliminate this remaining echo? - Is there a hardware or software echo canceller that will do a more thorough job of it? - How is the HPEC in dealing with this echo? _______________________________________________ --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
