[Asterisk-Users] BAD/GOOD Echo Cancel

[Rich Adamson]

> >> I put a Tellabs 64ms echo canceller into my facility this weekend and 
> >> am praying that it removes are echo problem.  If it does, I plan on 
> >> making it a standard on my Asterisk installs that have a channel bank 
> >> or T1.
> >>
> >
> > Well, the day is almost over here and not one echo reported today.  
> > Very impressive!  I had 5 more cards delivered today.
> >
> 
> Just as a follow up to this. 
> 
> I purchased 5 Tellabs 64ms cards on ebaY.  The very 1st card that I put 
> into production worked quite nicely (Little residual echo, but very much 
> an improvement).  I was on site this weekend and figured I would test 
> out the remaining cards, one at a time to confirm they were in working 
> condition.  This upcoming Monday, I had many complaints of echo.  Went 
> back Tuesday morning and went over the settings of the previous card 
> compared to this replacement.  I turns out that only 1 of the 5 cards 
> had option 38 available (Send Side Echo Cencellation).
> 
> So, if you are in the market for one of these cards because of local 
> echo, you'll want to confirm with the vendor of 'Send side Echo 
> Cancellation', or at least ask him to check for option 38 after powering 
> up. Out of the 5 purchased, only 1 had it.

I've never used a Tellabs before, but might try changing the input and
output analog lines around (eg, reverse it). Don't have a clue if that
would really work.