[Asterisk-Users] Re: Echo and crackle

[M.Hockings]

Thanks Steve, it is good to know that going to the digium card is likely 
to reduce the echo.

As you say, it is much cheaper than Sagoma.  Here in Canada the Digium 
FXO board is just under $100 but a suitable Sagoma with FXO, FXS and 
hardware echo can is about $650 !

Mike


Steve Jones wrote:
> I went through the same thing on my home system a couple months ago, and
> asked similar questions..  The "conventional wisdom" is that "it
> depends"...  It depends on your local loop length, quality, taps on the
> line, etc..  
> 
> It seems that most people who have the sangoma cards with hardware echo
> cancellation are happy, but I didn't have that kind of money to spend on
> my home system, so I bought the TDM400 card.  In my case, I bought two
> FXO and one FXS....  Also just "in my case", the difference was huge -
> All of a sudden my echo problems were gone.  So, although I probably
> would have been better off with the hardware echo, in my particular
> case, the Digium works great, and did make a huge difference over the
> voice modem I had been using.
> 
> Just for comparisons sake, my two FXOs are connected to:  1 Vonage ATA
> (Motorola), and one Verizon pots line.  I am about 2.5 miles from the
> CO, but I don't know the path that the cable takes, or if there's a SLC
> somewhere, so I don't know how long the loop is.  The line is DSL
> qualified, so I don't think there's a SLC, but I'm not positive..
> 
> Since you've already got the card, you'd probably be able to get the FXO
> for around $65, right?  I'd say that is your best bet, with very little
> money risked..
> 
> Good luck!!
> 
> -Steve
> 
> -----Original Message-----
> From: M.Hockings [mailto:veeshooter at hockings.net] 
> Sent: Saturday, June 17, 2006 1:23 AM
> To: asterisk-users at lists.digium.com
> Subject: [Asterisk-Users] Echo and crackle
> 
> We are running asterisk with a single POTS line for local calls and a 
> voip line for long distance.  Whenever we receive a call on the POTS 
> line it is more than likely, but not always, going to have significant 
> distracting echo.  In addition to that there is occasional heavy crackle
> 
> or static.  I have tried to follow the guidelines at :
> http://www.voip-info.org/wiki/view/Asterisk+echo+cancellation
> but it does not seem to have made much difference.
> 
> Currently we are using a X101P for the POTS line and a TDM401B (TDM400P 
> with one FXS port) for the conventional telephones.  From what I have 
> read, it may help to use an FXO port on the TDM400P rather than the 
> X101P for the POTS line.
> 
> What is the "conventional wisdom" about the echo in this configuration 
> and what causes the crackle and how should I tackle that?  I have tried 
> rebooting/power-cycling the machine to reset the hardware but it really 
> hasn't noticeably helped.
> 
> Is there anything else that I can try?
> 
> Thanks,  Mike