[asterisk-users] The High Performance Echo Canceller (HPEC)

[Matthew Fredrickson]

On Feb 15, 2007, at 3:17 AM, Wireless wrote:

>
> ----- Original Message -----
> From: "Nic Bellamy" <nicb-lists at vadacom.co.nz>
> To: "Asterisk Users Mailing List - Non-Commercial Discussion"
> <asterisk-users at lists.digium.com>
> Sent: Tuesday, February 13, 2007 8:40 PM
> Subject: Re: [asterisk-users] The High Performance Echo Canceller 
> (HPEC)
>
>
>> Larry Shields wrote:
>>> I recently read about the following new technologies from Digium.  
>>> Has
>>> anyone tried the new HPEC or knows when it will be available?
>> It's out now, and I've tried it - the difference between HPEC and MG2
>> from trunk is stunning - in situations with bad echo where MG2 can 
>> take
>> ten or more seconds to converge to a reasonable degree, HPEC does it 
>> in
>> perhaps 300ms - converging on my intake of breath before I say 
>> "hello",
>> and absolutely no echo after that unless I purposefully go out of my 
>> way
>> to screw it up (whistling/blowing into the handpiece for instance - 
>> even
>> then, the malfunction is minimal).
>>
>> You can now buy it from the Digium website (US$10 per channel), or if
>> you have an in-warranty Digium card, email through the serial numbers 
>> to
>> Digium support and they'll give you a key (this is what I did).
>>
>> You'll need Zaptel 1.2.13 to make it go.
>>
>> It does take quite a bit of CPU though - perhaps 70% more compared to
>> MG2-trunk for the same number of taps from my rough measurements.
>>
>> Cheers,
>>     Nic.
>>
>> -- 
>> Nic Bellamy,
>> Head Of Engineering, Vadacom Ltd - http://www.vadacom.co.nz/
>>
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>
> Does anyone know if the HPEC will work on a Sangoma A200 / 2 port FXO 
> card?
> (I'm assuming so as it still uses Zapel)  I've 2 PSTN lines one of 
> which I
> cannot get rid of the echo, I've tried a 2GHz machine as apposed to my
> normal P3 650MHz and this made no difference. Would the 650Mhz be 
> enough to
> run HPEC on one line (I assume only needing one licence)
>
> This is what Digium say on their web site:
> Digium recommends that users requiring 8 channels at 1024 taps run a PC
> comparible to a 3.0 GHz Pentium 4, while users only requiring 4 
> channels at
> 1024 taps may run a 2.5 GHz Pentium Celeron. The CPU requirements are 
> such
> that it is impractical to operate this echo canceller at 1024 taps for 
> a
> full T1 or E1 of channels.

Yes, it will work with any card that uses zaptel.  You  just have to 
pay a per port fee to use it with a non-digium card.  I'm not sure 
about the performance requirements for one port though.  You could try 
it with a low tap count and keep bumping up your taps 
(echocancel=[32,64,128,256,512,1024]) until it cancels the echo though. 
  That way you'd only use as much cpu as you absolutely have to.

Matthew Fredrickson