[Asterisk-Users] Fun with Echo

[Brian Swan]

Yes, I think I may.  I'd be curious to see if more taps, plus the  
"pre-train" patch may work for me... I'll let the group know what  
happens.  I'm not too worried about processor usage.  We only have  
three lines, and it's a 2ghz processor with 2gigs of ram... :)

Thanks,
Brian

On Jun 9, 2006, at 12:38 PM, Colin Anderson wrote:

> More taps in the Zaptel echo can = higher CPU usage + longer  
> training times.
> In my experience, specifying an overly high number of taps (even  
> 256) will
> bog the system when it is under load and lead to subjective delays  
> in the
> audio path. But if you are going to be only doing 1 or 2 concurrent  
> calls,
> why not experiment?
>
> -----Original Message-----
> From: Brian Swan [mailto:swannie at swannie.net]
> Sent: Friday, June 09, 2006 11:29 AM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: Re: [Asterisk-Users] Fun with Echo
>
>
> My wife is the customer, so she tends to give me funny looks when I
> ask her to sign waivers. ;) In all seriousness, though, I do recall
> reading that the 256 tap limit is "enforced" in software and that you
> can add/remove/whatever a few lines of code, and go up to 1024 (or
> greater I'd assume).  Has anyone tried this?  I'm considering
> attempting it this weekend to see if it does anything.  Does more
> taps always = better echo cancelation?
>
> Thanks!
> Brian
>
> On Jun 9, 2006, at 12:15 PM, Mike Fedyk wrote:
>
>> Steve Davies wrote:
>>> On 6/9/06, Dr. Michael J. Chudobiak <mjc at avtechpulse.com> wrote:
>>>>
>>>> Consider getting a Sangoma A200D
>>>> (http://www.sangoma.com/datasheets/p_a200-specs) with the optional
>>>> hardware echo canceller module. It "just works" for echo
>>>> cancellation;
>>>> no tweaks required. It takes a while to figure out how to install
>>>> it,
>>>> but once it's working it's great!
>>>>
>>>
>>> Yes, I must agree that hardware echo cancellation from Sangoma  
>>> (and I
>>> am sure Digium and others) is excellent, but it does add to the cost
>>> quite significantly sometimes.
>> If you haven't had your client sign a waiver that there maybe echo
>> because of the cheap hardware, then don't use the tdm400p.  I've
>> wondered why the software echo can in zaptel doesn't go up to 1024
>> taps and causes major problems at 256 taps.  The tdm400p cards
>> don't have a high port density, you'd run out of slots before
>> hitting CPU barriers so why not use some of those resources for an
>> echo can with a longer tail?
>>
>> Use either the sangoma cards with echo can, or get a tdm2400p with
>> echo can.  You will have happier customers if you do.
>> _______________________________________________
>> --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
>
> _______________________________________________
> --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
> _______________________________________________
> --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