Likely all of your calls are experiencing the talker echo, but the sip caller is the only one who detects it as a "bad thing" because the reflection is being delayed until it's detectable by the codecs and transports involved. For the users who don't have transport delays the echo simply manifests itself as louder 'sidetone' - See: http://www.voip-info.org/wiki-Echo+and+Sidetone
You can test for this by chaging SIP codecs to something that introduces less or more delay (eg. ulaw) and seeing if the echo is more pronouced. The soloution is either to get rid of the source of the reflections as much as possible - usually by 'balancing the hybrid' on your end to start with, or by tweaking the zaptel echo canceller parameters in zapata.conf (or, if you're feeling adventurous, zaptel/mec2_const.h) to get it to converge properly on the reflections your encountering. I have managed to get it go cancel fine on about 90% of my calls, but there are some which simply defy cancellation. In each of these cases it's 100% repeatable and seems to be something to do with the remote parties line or specific telephone characteristics. Hope that helps. Kris Boutilier Information Systems Coordinator Sunshine Coast Regional District > -----Original Message----- > From: Paul Dugas [mailto:[EMAIL PROTECTED] > Sent: November 5, 2004 10:41 AM > To: Asterisk Mailing List > Subject: [Asterisk-Users] Adjusting txgain/rxgain {clip} >I also have occasional echo issues; internal caller on a SIP phone hears echo of self > calling out via X100P FXO; called doesn't hear any echos. > {clip} _______________________________________________ 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
