asterisk users - Dec 2005 - Echo cancellation over satellite link

Hi,
   
  Just wondering, is the echo canceller in the TE411P capable of cancelling the
echo caused by the delay over satellite link (i.e. approx 400 ms delay)?
   
  Does anyone have any success story to share? 
   
  I'm kinda stuck with a really2 annoying echo... adjusting the gain
didn't help... and what should my zapata.conf look like for effective echo
cancellation?
   
  Thanks in advance ^_^

		
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On 12/6/05, funny guy <asteriskmail@yahoo.com>
wrote:
> Hi,
>
> Just wondering, is the echo canceller in the TE411P capable of cancelling
> the echo caused by the delay over satellite link (i.e. approx 400 ms
delay)?
>
> Does anyone have any success story to share?
>
> I'm kinda stuck with a really2 annoying echo... adjusting the gain
didn't
> help... and what should my zapata.conf look like for effective echo
> cancellation?
>
> Thanks in advance ^_^
>
 No. Neither Digium nor Sangoma I believe are putting in hardware cans
that would support a 400ms+ tail. I think the most you're going to get
is 128ms.

--
Bird's The Word Technologies, Inc.
http://www.btwtech.com/

In software asterisk can support more than that, no?

-----Original Message-----
From: asterisk-users-bounces@lists.digium.com
[mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of BJ Weschke
Sent: Tuesday, 6 December 2005 17:03
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [Asterisk-Users] Echo cancellation over satellite link

On 12/6/05, funny guy <asteriskmail@yahoo.com>
wrote:
> Hi,
>
> Just wondering, is the echo canceller in the TE411P capable of
cancelling
> the echo caused by the delay over satellite link (i.e. approx 400 ms
delay)?
>
> Does anyone have any success story to share?
>
> I'm kinda stuck with a really2 annoying echo... adjusting the gain
didn't
> help... and what should my zapata.conf look like for effective echo
> cancellation?
>
> Thanks in advance ^_^
>
 No. Neither Digium nor Sangoma I believe are putting in hardware cans
that would support a 400ms+ tail. I think the most you're going to get
is 128ms.

--
Bird's The Word Technologies, Inc.
http://www.btwtech.com/
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2 Things...  You probably know anyway...
 
Early echo cancel for satellite just used half duplex switching as a way to
get around the echo (This led to the echo suppess tone being used for faxes
and modems to allow full duplex).
 
>From my Telephony days the echo comes mostly from a mismatch in the hybrid
at the other end of the link from where the echo is heard.
 
Regards
Randall Prentice

Just wondering, is the echo canceller in the TE411P capable of cancelling
the echo caused by the delay over satellite link (i.e. approx 400 ms delay)?

 
Does anyone have any success story to share? 
 
I'm kinda stuck with a really2 annoying echo... adjusting the gain
didn't
help... and what should my zapata.conf look like for effective echo
cancellation?
 
Thanks in advance ^_^

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funny guy wrote:
> Just wondering, is the echo canceller in the TE411P capable of 
> cancelling the echo caused by the delay over satellite link (i.e. approx 
> 400 ms delay)?
> 
> Does anyone have any success story to share?
> 
> I'm kinda stuck with a really2 annoying echo... adjusting the gain 
> didn't help... and what should my zapata.conf look like for effective 
> echo cancellation?
> 
Echocan should be placed as close to the PSTN as you can.

I.e. Asterisk -> high latency connection -> echocan -> PSTN.

Not Asterisk -> echocan -> high latency connection -> PSTN.

On Tuesday 06 December 2005 00:58, funny guy wrote:
>   Just wondering, is the echo canceller in the TE411P capable of cancelling
> the echo caused by the delay over satellite link (i.e. approx 400 ms
> delay)?
No.  Use MARK2, KB1 or MG2 and enable the agressive mode -- this converts your 
link to a half-duplex link and you won't have any echo, but it will sound 
very walkie-talkie-like... but given that you've got damn near one-half 
second latency I don't think that's going to be a problem.

-A.