[Asterisk-Users] Huge Echo

[Marek Zachara]

On Friday 09 of September 2005 20:15, steve at daviesfam.org wrote:
> On Fri, 9 Sep 2005 steve at daviesfam.org wrote:
> > Could you have a cabling issue?  Like one leg of the pair grounded?  I'm
> > not really a telco engineer but I have this vague idea that this can
> > cause echo trouble?  Can anyone confirm or deny?
>
> Ah yes,
> http://www.voip-info.org/tiki-index.php?page=Asterisk+echo+analog+lines
> talks about grounded legs of the call and bridge taps.
>
> I suspect you could also get the effect of a grounded leg if you only
> actually have one side of the pair connected; a return path via ground may
> be found to give you a very unbalanced connection.
>
> Your RJ11 cable could be wrong and on the wrong pins to result in just one
> leg being connected.
>

Until the cable wiring is totally different i don't think this should be the 
case. We use pins 2&3 in the RJ connector - and since all US equipment (like 
external modems) have been working well i assume the same wiring is used 
there. I'll check on monday whether the card does not ground one of the 
wires. If so, a small 1:1 transformer could be a solution.

Marek