Hello, We're in the process of setting up an Asterisk server, and are having echo problems. We have a Digium TE110P, and have tried the MG and MARK2 AGGRESSIVE echo cancellers, with a variety of gain levels and training times, and with both trunk and 1.2 branch versions of Zaptel, Libpre, and Asterisk. In all cases, callers from the PSTN hear their own voice echoed back after 1.5-2 seconds; none of these adjustments made a difference, except adjusting gain made the echo quieter. We followed these instructions in trying to eliminate echo: http://www.asteriskdocs.org/modules/tinycontent/content/docbook/current/docs-html/x1695.html Our lines come in from the telco in a PRI, then connect to a Tadiran switch which hands the lines off to Asterisk over a T1 card. We have done loopback tests with the Digium card with a loop plug in it. We're a bit stumped as to what to try next. Any suggestions or advice? Thanks ---Scott.
Hi, Did you try to increase echotraining ?? echo training = 800 .. @++> Hello, > > We're in the process of setting up an Asterisk server, and are having > echo problems. We have a Digium TE110P, and have tried the MG and > MARK2 AGGRESSIVE echo cancellers, with a variety of gain levels and > training times, and with both trunk and 1.2 branch versions of > Zaptel, Libpre, and Asterisk. In all cases, callers from the PSTN > hear their own voice echoed back after 1.5-2 seconds; none of these > adjustments made a difference, except adjusting gain made the echo > quieter. > > We followed these instructions in trying to eliminate echo: > > http://www.asteriskdocs.org/modules/tinycontent/content/docbook/current/docs-html/x1695.html > > Our lines come in from the telco in a PRI, then connect to a Tadiran > switch which hands the lines off to Asterisk over a T1 card. > > We have done loopback tests with the Digium card with a loop plug in > it. > > We're a bit stumped as to what to try next. Any suggestions or > advice? > > Thanks > > ---Scott. > _______________________________________________ > --Bandwidth and Colocation provided by Easynews.com -- > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users >
As I understand it, the echo cancelers in Asterisk only work with the Analog cards (FXS/FXO). If you are getting echo on a digital line, there is a problem with either a DAC, the T1 clocking, or you are getting bit errors. You have a Switch in the middle - perhaps the switch is doing doing digital-analog conversions instead of sending the digital data straight through. The cause of the echo could very well be there, and the echo cancelers (even if they worked on a digital line) would not help because the cause of the echo is somewhere else, not at the Digium card. Check your Tadiran switch for any echo cancel options. I'm not familiar with that switch so I am no help to you on that, but I am pretty sure that its not the Digium card or Asterisk. Regards, --Jason Bachman Scott Gifford wrote:> Hello, > > We're in the process of setting up an Asterisk server, and are having > echo problems. We have a Digium TE110P, and have tried the MG and > MARK2 AGGRESSIVE echo cancellers, with a variety of gain levels and > training times, and with both trunk and 1.2 branch versions of > Zaptel, Libpre, and Asterisk. In all cases, callers from the PSTN > hear their own voice echoed back after 1.5-2 seconds; none of these > adjustments made a difference, except adjusting gain made the echo > quieter. > > We followed these instructions in trying to eliminate echo: > > http://www.asteriskdocs.org/modules/tinycontent/content/docbook/current/docs-html/x1695.html > > Our lines come in from the telco in a PRI, then connect to a Tadiran > switch which hands the lines off to Asterisk over a T1 card. > > We have done loopback tests with the Digium card with a loop plug in > it. > > We're a bit stumped as to what to try next. Any suggestions or > advice? > > Thanks > > ---Scott. > _______________________________________________ > --Bandwidth and Colocation provided by Easynews.com -- > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > >
> We followed these instructions in trying to eliminate echo:>http://www.asteriskdocs.org/modules/tinycontent/content/docbook/current/doc >s-html/x1695.html>Our lines come in from the telco in a PRI, then connect to a Tadiran >switch which hands the lines off to Asterisk over a T1 card.Checkout the Digium KB: http://kb.digium.com/19/ You will see a suggestion to adjust the gain levels as well. Even though the echo is there, it helps to not make it noticeable to the users. I just found this as well, although they are trying to sell their product at the same time, it helps explain echo and some steps in Asterisk for reducing echo: http://www.xorcom.com/pdfs/AB007_Echo.pdf Michael L. Young