[Asterisk-Users] Re: X100P / Echo / ZTMONITOR CAN2,3, etc.
Andrew Kohlsmith wrote: If you're getting echo of your own voice, but the remote is getting a clear signal, then Asterisk echo cancellation is working properly. It is the remote provider not echo cancelling properly. I don't buy it. If that were the case then why would I not _also_ get my own voice echoed with a regular phone plugged in to the same POTS line? And you shouldn't! Theory holds that exactly the opposite is true. With no echo cancellation at all and with an unbalanced hybrid, the local party hears the echo and the remote party does not. This is because the local hybrid listens to itself talking to the pots line and sends what it hears back to the local listener. If the hybrid is perfectly balanced, it will subtract out what it is saying to the pots line before it returns the signal to the local caller. The problem is that it rarely does a very good job of this. Neither do many commercial channel banks. There are a few common hardware glitches that can make echo a lot worse, such as a shorted leg or corroded connection in the PSTN wiring, having a hard wired extension connected to the same line or simply having a lousy CO switch at the other end. The first 2 the phone provider should diagnose and fix for you. The strange thing here is that asterisk is not removing the echo. I did notice that the 0.7.1 tar did not do the echo cancel very well and Mark suggested that I go back to the CVS, which did wonders. You might also verify that echo cancellation is actually turned on. Enter zap show channel x at the CLI, where x is one of your defined zap channels. If it's enabled, somewhere in the output you should see Echo Cancellation: xx taps, Currently On/Off. The On/Off will change from Off to On when a call is bridged. If it is not enabled, check the definitions in zapata and in your make file. ___ 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
RE: [Asterisk-Users] Re: X100P / Echo / ZTMONITOR CAN2,3, etc.
Would it be possible here to make the echo canceler option (2,3, etc.) a configuration file setting, maybe in Zapata rather than compile time? What does this do to system resources? - Brent -Original Message- From: [EMAIL PROTECTED] [mailto:asterisk-users- [EMAIL PROTECTED] On Behalf Of Stephen R. Besch Sent: Tuesday, February 17, 2004 11:05 AM To: [EMAIL PROTECTED] Subject: [Asterisk-Users] Re: X100P / Echo / ZTMONITOR CAN2,3, etc. Andrew Kohlsmith wrote: If you're getting echo of your own voice, but the remote is getting a clear signal, then Asterisk echo cancellation is working properly. It is the remote provider not echo cancelling properly. I don't buy it. If that were the case then why would I not _also_ get my own voice echoed with a regular phone plugged in to the same POTS line? And you shouldn't! Theory holds that exactly the opposite is true. With no echo cancellation at all and with an unbalanced hybrid, the local party hears the echo and the remote party does not. This is because the local hybrid listens to itself talking to the pots line and sends what it hears back to the local listener. If the hybrid is perfectly balanced, it will subtract out what it is saying to the pots line before it returns the signal to the local caller. The problem is that it rarely does a very good job of this. Neither do many commercial channel banks. There are a few common hardware glitches that can make echo a lot worse, such as a shorted leg or corroded connection in the PSTN wiring, having a hard wired extension connected to the same line or simply having a lousy CO switch at the other end. The first 2 the phone provider should diagnose and fix for you. The strange thing here is that asterisk is not removing the echo. I did notice that the 0.7.1 tar did not do the echo cancel very well and Mark suggested that I go back to the CVS, which did wonders. You might also verify that echo cancellation is actually turned on. Enter zap show channel x at the CLI, where x is one of your defined zap channels. If it's enabled, somewhere in the output you should see Echo Cancellation: xx taps, Currently On/Off. The On/Off will change from Off to On when a call is bridged. If it is not enabled, check the definitions in zapata and in your make file. ___ 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 ___ 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
[Asterisk-Users] Re: X100P / Echo / ZTMONITOR CAN2,3, etc.
[EMAIL PROTECTED] wrote: The strange thing here is that asterisk is not removing the echo. I did notice that the 0.7.1 tar did not do the echo cancel very well and Mark suggested that I go back to the CVS, which did wonders. You might also verify that echo cancellation is actually turned on. Enter zap show channel x at the CLI, where x is one of your defined zap channels. If it's enabled, somewhere in the output you should see Echo Cancellation: xx taps, Currently On/Off. The On/Off will change from Off to On when a call is bridged. If it is not enabled, check the definitions in zapata and in your make file. I have checked my zapata.conf file and fiddled with the settings so far I cannot get echocancel to work. Although I don't have echo problem now. [channels] ; language=en context=incoming amaflags=default cancallforward = yes callwaiting = no busydetect = no callprogress = no musiconhold = default rxgain=0.0 txgain=0.0 immediate=no echocancel = yes echocancelwhenbridged = yes echotraining = yes usecallerid = yes threewaycalling = yes callwaitingcallerid = yes callerid = asreceived signalling = fxs_ks callreturn = yes channel = 1 At the console, the output for show channel is : Channel: 1 File Descriptor: 19 Span: 1 Extension: Context: incoming Caller ID string: Destroy: 0 Signalling Type: FXS Kewlstart Owner: None Real: None Callwait: None Threeway: None Confno: -1 Propagated Conference: -1 Real in conference: 0 DSP: no Relax DTMF: no Dialing/CallwaitCAS: 0/0 Default law: ulaw Fax Handled: no Pulse phone: no Echo Cancellation: 128 taps, currently OFF Actual Confinfo: Num/0, Mode/0x Actual Confmute: No I have a look at the Makefile in zapata directory and do not see anything needs to be tweak. David Kwok ___ 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
