> > Message: 1 > Date: Mon, 19 Jun 2006 10:02:08 +0100 > From: David Caldwell <[EMAIL PROTECTED]> > Subject: [Astlinux-users] Bad echo on incoming calls on Zap trunk > To: [EMAIL PROTECTED] > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset="us-ascii" > > Hi all, > > I'm trying to improve echo for all incoming calls that come > into Asterisk via PTSN onto a TDM400 card and then on to a > SIP phone. The echo starts off quite loud with about 1/2 > second delay and after 10 to 20 seconds it is cancelled. > I've tried altering various settings in > /etc/asterisk/zapata.conf but cannot seem to improve the echo > situation beyond what I've described above. My echo settings > are currently set like this: > > echotraining=yes > echocancelwhenbridged=yes > echocancel=256 > > I read somewhere that 'echocancel' increases in powers of 2 > like binary (ie: 32, 64, 128, 256, etc) - is this correct? > Am I being too idealistic by wanting less echo than what > I've described above? How has everyone else got their echo > cancelling set? Is there anything else I can try? > > Other than playing with the above variables, I've tried a > couple of different handsets without improvement. > > Many thanks, > > David.
I am no expert by any means but I do know from personal experience that you can and probably will drive yourself insane messing with those settings and using others suggestions, messing with cable lengths, server location, etc. or considering other factors such as phases of the moon, current events, your astroligical sign. EVERY physical location with wired PSTN has different signal levels, impedance, loop length back to the telco central office etc. and therefore EVERY physical location is different. What works at one location for one person does not apply to another location. Depends on a lot of things and the software echo can is often not adequate enough to deal with it. There is plenty of evidence to support that conclusion past and present. There has been a lot of effort to improve the software echo cans but no matter how brilliant the code/algorithms they will NEVER be as good as hardware. That is a technical fact. Echo is an analog phenomenon. Infinitely variable and instantaneously changing. IMHO, if you have the budget, save yourself the headaches and get yourself a TDM card with hardware echo can. It will eliminate all echo and improve your overall sound quality. I seriously doubt it has anything to do with your analog cable length unless that length is ridiculously long or unless you have a bad connection that is throwing your signal/impedance way out (not likely). _______________________________________________ Astlinux-users mailing list [email protected] http://lists.kriscompanies.com/mailman/listinfo/astlinux-users Donations to support AstLinux are graciously accepted via PayPal to [EMAIL PROTECTED]
