asterisk-users-bounces@lists.digium.com wrote:> In the following setup: > call coming from a pstn line -> into FXO card -> asterisk -> SIP > phone > > i get an incredible loud echo in the SIP phone (about 0,5-1s) > (everything i speak into SIP phone microphone i hear in its > speaker). The person calling from PSTN is not getting any echo.Make sure you're not playing the recorded sound from your microphone back to your loudspeakers. -- Andreas Sikkema bbned NV Van Vollenhovenstraat 3 3016 BE Rotterdam t: +31 (0)10 2245544 f: +31 (0)10 413 65 45
On Friday 09 of September 2005 13:14, Andreas Sikkema wrote:> asterisk-users-bounces@lists.digium.com wrote: > > In the following setup: > > call coming from a pstn line -> into FXO card -> asterisk -> SIP > > phone > > > > i get an incredible loud echo in the SIP phone (about 0,5-1s) > > (everything i speak into SIP phone microphone i hear in its > > speaker). The person calling from PSTN is not getting any echo. > > Make sure you're not playing the recorded sound from your > microphone back to your loudspeakers.How could I have done that? I'm not recording any sound (at least nothing i'm aware of). The echo doesn't happen when the call is incoming from SIP provider (instead of PSTN) - so i assume the problem is related to the analog line. The SIP phone is stand-alone AT-320 Marek
No that just means you are not calling ztmonitor properly. Try running ~# ztmonitor 1 -v Jared Armstrong OmniSpear, Inc. Web & Network Solutions -----Original Message----- From: Marek Zachara [mailto:marek.zachara@conexe.pl] Sent: Friday, September 09, 2005 10:43 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Huge Echo On Friday 09 of September 2005 16:08, Soner Tari wrote:> >> Gain setting are important of course. You could use ztmonitor forthat.> > > > the asterisk server is a racked machine with no sound card. so can'tuse> > the > > ztmonitor. If everything fails i'll dig it out and try this > > You don't need a soundcard to use ztmonitor, what do you mean by that? > Marek, you are making me suspicious about whether you've really readwiki> in detail. >Well, i did read it. And as per soundcard - have you tried to run ztmonitor without it? When i tried i just got: arnor:~# /usr/src/zaptel-1.2.0-beta1/ztmonitor 1 Unable to open /dev/dsp: No such file or directory Cannot open audio ... so i guess it needs a soundcard after all... Anyway, i installed a soundcard and run the ztmonitor. I went with the rxgain/txgain down to -6.0 ... the echo is not that loud anymore, but still is quite annoying. i'm at loss... no other bright ideas ... Marek
Did you try to get a milliWatt test phone number from your telco? It was really easy for me. I called the business office and told them that "my new digital pbx was having some awful echo trying to deal with their lines; all I needed was a milliWatt test line to balance my receive and transmit gains properly". I then had to tell her what a milliWatt test line did and why I thought it would help me; she didn't know what it was, but she was more than happy to have repair call me to see if they could help me. Less than a half an hour later, somebody called up, asked for me, and said "lets see.. milliWatt test line for Sitka... 747-1100" as easy as that. I spent a half an hour making calls to this number out of my (phew, only three!) zap lines and haven't had echo troubles since. BTW, the area code on that one is 907 if you want to listen to what it should sound like. If the telcos were to route amongst themselves fully digitally, wouldn't you be able to use my mW test line no matter where you are? As long as the only analog link between it and you was your local copper pair? Just in case, I wouldn't recommend anybody tuning themselves to this mW source. Mojo Jared Armstrong wrote: No that just means you are not calling ztmonitor properly. Try running ~# ztmonitor 1 -v Jared Armstrong OmniSpear, Inc. Web & Network Solutions -----Original Message----- From: Marek Zachara [mailto:marek.zachara@conexe.pl] Sent: Friday, September 09, 2005 10:43 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Huge Echo On Friday 09 of September 2005 16:08, Soner Tari wrote: >>>> >> Gain setting are important of course. You could use ztmonitor for that. >>> > >>> > the asterisk server is a racked machine with no sound card. so can't use >>> > the >>> > ztmonitor. If everything fails i'll dig it out and try this > >> >> You don't need a soundcard to use ztmonitor, what do you mean by that? >> Marek, you are making me suspicious about whether you've really read wiki >> in detail. >> Well, i did read it. And as per soundcard - have you tried to run ztmonitor without it? When i tried i just got: arnor:~# /usr/src/zaptel-1.2.0-beta1/ztmonitor 1 Unable to open /dev/dsp: No such file or directory Cannot open audio ... so i guess it needs a soundcard after all... Anyway, i installed a soundcard and run the ztmonitor. I went with the rxgain/txgain down to -6.0 ... the echo is not that loud anymore, but still is quite annoying. i'm at loss... no other bright ideas ... Marek
Does anyone know how to use ztmonitor to set gain on a PRI circuit via a TE410P card, or is it just for FXO? -----Original Message----- From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of Marek Zachara Sent: Friday, September 09, 2005 2:55 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Huge Echo> > Pull the clone card out of the system and look for the chipset numbers> on the card. Go to the chip manufacturers web site and find the specs > for that chip set. The specs will likely tell you the chipset was > designed for the US 600 ohm impedance telephone network, and if your > country's telco specs are different (which I'm very sure they are), > through away the clone card. Without proper impedance matching there > isn't anything your going to be do to fix the problem.I can check the chip on monday, but local telco impedance requirements are 600 ohms - just like US.> > > > I'm thinking about playing around with increasing/decreasing > > resistance by placing additional resistors in the circut. Messy, but> > if it could help... What do you think? > > Adding resistance has nothing at all to with impedance matching. > Resistance will impact the DC loop, but not the AC impendance. The AC > impedance is a function of how the chipset was designed. >AFAIR, the impedance is not a simple factor, but a combination of passive resistance plus reactance - which usually varies within measured frequency range. Therefore channging the device resistance WILL change its impedance. I know the result will not be perfect, but at least i hope for better load match than it is now. I assume the specified impedance is required within PSTN frequencies which will be roughly 100-4khz, right? Marek _______________________________________________ --Bandwidth and Colocation sponsored by Easynews.com -- Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users The contents of this email message and any attachments are confidential and are intended solely for addressee. The information may also be legally privileged. This transmission is sent in trust, for the sole purpose of delivery to the intended recipient. If you have received this transmission in error, any use, reproduction or dissemination of this transmission is strictly prohibited. If you are not the intended recipient, please immediately notify the sender by reply email and delete this message and its attachments, if any.