I think there is a negligible difference btw 14844 and 14500 so it was rounded down to 14500. When you do the test you will understand why.
I am still not sure if those numbers are correct though as they are full scale so that would make them 0dbm? To achieve -3dbm I believe you would want to shoot for half that which would be 7250 assuming it's linear (which I have no clue). Anyone know for sure what to do because I am getting confused a bit myself? > -----Original Message----- > From: Andrew Kohlsmith [mailto:[EMAIL PROTECTED] > Sent: Tuesday, October 11, 2005 9:31 AM > To: [email protected] > Subject: Re: [Asterisk-Users] PRI echo issues: solvable? > > On Tuesday 11 October 2005 11:49, alan wrote: > > After solving the other "low hanging fruit" audio issues in our > > Asterisk PBX, we are left with occasional cases of severe > echo which > > we have not found a solution for yet. > > > Our system: > > - Asterisk 1.2.0-beta1 > > - TE110P on a PRI > > - TDM04 and TDM40, but these are unrelated to current echo issues > > - Fedora core 3 > > - Echo canceller KB1 > > Add to the mix > Asterisk CVS HEAD (always within a couple of weeks of today) > Slackware 10.1 > TE405 and TE406 (with and without VPM support) Tried with > various motherboards and chipsets (all P4) > > > Most calls have minimal, acceptable echo levels. But > occasionally, we > > get a call where the echo is delayed by a substantial amount > > (sometimes around 250ms), and sounds as loud as the remote party. > > Yup. > > > One example: when one number (local to the same CO as our > PRI) calls > > us, the echo on our end is unbearably bad. When we call > them, No Problem. > > I've never seen that, it's always when we call out. Certain > numbers will always trigger it. 888-737-4787 (IPC Resistors, > it dumps into an IVR so it's safe to call) is one such > number, but we have local numbers that hit other COs which > exhibit this problem as well so it's not a specific CO or > switch problem. > > I have just verified today with the 888 # mentioned above > that zaptel is NOT disabling its echo canceller. dmesg shows > no "disabling echo canceller due to tone" message and "zap > show channel [affectedchannel] shows that the echo canceller > is configured correctly (128 taps for us) and is ON. > > I hope to do further testing as I am made more aware of the > numbers causing the issues. > > > - Gain tuning: Is the ztmonitor quantitative target value 14500 or > > 14844? These two sources conflict on this point: > > http://www.voip-info.org/wiki/view/Asterisk+zapata+gain+adjustment > > I think you want to achieve an effective value of -2 to > -3dBm. I'm unsure what "value" this is in ztmonitor -v. I > know this should not be needed at all on a PRI or other > digital connection. > > -A. > > _______________________________________________ --Bandwidth and Colocation sponsored by Easynews.com -- Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
