[Asterisk-Users] TE411P Really Bad Echo

[Rob Lith]

Sorry, that's correct - so when experimenting with s/w echo can try the
different options.

Rob

On 2/11/06, asterisk at oneringnetworks.com <asterisk at oneringnetworks.com>
wrote:
>
> I thought that if the VPM was detected then you didn't have any control as
> to which algorithm was used.
>
> I was under the impression that the algorithms were only used for the
> software echo cancellation.
>
> At this point I'll give anything a try.
>
> Stagg Shelton
> www.oneringnetworks.com
>
> -----Original Message-----
>
> From:  Rob Lith <rob at connection-telecom.com>
> Subj:  Re: [Asterisk-Users] TE411P Really Bad Echo
> Date:  Sat Feb 11, 2006 10:17 am
> Size:  4K
> To:  Asterisk Users Mailing List - Non-Commercial Discussion<
> asterisk-users at lists.digium.com>
>
> Stagg
>
> I don't think it's a matter of trying echocancel on and off, it is a
> matter
> of tuning your system to your local PSTN - this is a combination of trying
> the different echocan alogrithims (i.e. MG2), the echotrainign etc and
> setting your txgain - too loud outgoing audio will result in echo.
>
> http://www.asteriskdocs.org/modules/tinycontent/content/docbook/current/docs-html/x1695.html#AEN1718
>
> Rob
>
> On 2/11/06, Stagg Shelton <asterisk at oneringnetworks.com> wrote:
> >
> > Yes, right now we are only using span 1 on the quad span card with plans
> > to pull in another T1 PRI when we get this echo problem solved.  The
> echo is
> > only experienced when the call terminates to traditional analog circuits
> > both local and long distance.  Calls to cell phones, and other known
> digital
> > circuits do not exhibit the symptoms.  I've been sent a few articles off
> > list which discussed the reasons why this may occur, imperfect impedance
> > where the digital circuit is switched to the analog circuit.
> >
> > In testing I've set echocancel=no made calls, and echocancel=yes and
> made
> > calls with no real audible difference.  I haven't done a zap show
> channel
> > while on a call with echo, but I plan to this weekend.  I was informed
> that
> > the number of taps would be shown.  I used a stop watch last night to
> try to
> > get the delay, and it was about 1/2 to 1 second delay and was continual
> so
> > long as I was talking.  It wasn't affected by differing acoustical
> > variations.  I tested this using handset, headset, and speakerphone.
> > Disabling VPM and recompiling zaptel or removing the VPM off the board
> > completely is the only thing that has any effect on the echo.  Hopefully
> the
> > zap show channel will provide to me another data point to help me
> determine
> > if the HW module is active.
> >
> > More to come...
> >
> > Stagg Shelton
> > www.oneringnetworks.com
> >
> >
> > Cory Andrews wrote:
> >
> > Stagg - I know you get a full 128ms tail of echo can on the Sangoma.  I
> > believe that on the TE411P, the 128ms tail is shared by all (4) spans,
> and
> > as you add additional spans up to maximum of 4, the echo can tail amount
> > decreases accordingly.  If you are running 4 spans, you have 32ms of
> echo
> > can tail on each span, not the full 128ms.
> >
> > Now that I'm reading back through your post thread, it looks like you
> were
> > only running 1 span on the TE411P, so you should have been getting the
> full
> > 128ms of echo can tail.  You may not find an improvement with the
> Sangoma.
> > I have never experience, nor heard of a 1-2 full second delay.  Trial
> and
> > error is likely your course of action.
> >
> > Cory J Andrews
> > ++++++++++++
> > VOIPSupply.com
> > 454 Sonwil Drive
> > Buffalo, NY 14225
> > ++++++++++++++
> > voice - 716.630.1555 X22
> > email - Cory at VOIPSupply.com
> > AIM - B2CORY
> >
> > ----- Original Message -----
> > *From:* Stagg Shelton <asterisk at oneringnetworks.com>
> > *To:* Asterisk Users Mailing List - Non-Commercial Discussion<
> asterisk-users at lists.digium.com>
> > *Sent:* Friday, February 10, 2006 11:34 PM
> > *Subject:* Re: [Asterisk-Users] TE411P Really Bad Echo
> >
> >  It was Digium's opinion that perhaps the card had a VPM.  We got a
> > replacement TE411P, I implemented it tonight and still the exact same
> echo
> > problem.  At this point I feel like I can rule out failed hardware.
> >
> > I contacted Digium support and now they are telling me it's something
> with
> > my carrier, and I should call them.  I called Bellsouth, and they ran a
> full
> > stress test on the circuit taking me offline for about 30 minutes.
> >
> > The end result is that the circuit test passed with no
> errors.  Bellsouth
> > says it's not in their network, Digium says its not their card, and I
> have a
> > te411p with VPM disabled in the wct4xx kernel module because something
> > doesn't work the way it should.  My customer is wanting to know about
> > sangoma cards with the echo cancellation, and at this point I'm nervous
> to
> > recommend any hardware.  I'm going to look into the sangoma that you
> > suggested.  Are there any other kinds of products that I could look into
> > either Passive or Active.
> >
> > Thanks
> >
> > Stagg Shelton
> > www.oneringnetworks.com
> >
> >
> > Matt wrote:
> >
> > try sangoma carrier grade 104d hardware EC card. we're using it ourself.
> >
> > Best Regards
> >
> > Matt
> > ----- Original Message -----
> > From: "Anthony Rodgers" <Anthony_Rodgers at dnv.org> <
> Anthony_Rodgers at dnv.org>
> > To: "Asterisk Users Mailing List - Non-Commercial Discussion"
> > <asterisk-users at lists.digium.com> <asterisk-users at lists.digium.com>
> > Sent: Tuesday, February 07, 2006 12:57 PM
> > Subject: Re: [Asterisk-Users] TE411P Really Bad Echo
> >
> >
> >    For what it's worth, we have been going through very similar issues
> > with a
> --- message truncated ---
>
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