[Asterisk-Users] Recommended FXO device

[Rich Adamson]

Chris Mason wrote:
> I have a client's installation that requires 4 lines PSTN interface only 
> so I am looking at 4 port FXO units. What works well with Asterisk and 
> is not exorbitant to purchase? Would a Sangoma remora be better?

The Sangoma A200D card has better echo canceller (if needed) compared to 
the Digium TDM card, plus the A200D card "does" support modem calls (eg, 
faxing, POS) when the modem is plugged into a fxs port on the same card 
as the fxo ports.

For external adapters, the only one that I've tested that functioned 
reliably was the Mediatrix 1204 at a rather heafty price. It did an 
excellent job with echo cancellation, audio levels, and audio quality; 
but, their implementation (about two years ago) was very non standard 
with absolutely no security, etc. That may have changed now, but at the 
time, it could only be configured using snmp and with an snmp community 
string of "public" (which could not be changed). Rather difficult to set 
up, but once configured it just worked.

I've tested a large number of other external adapters and have not found 
a single one that had a reasonable echo canceller built in. Many of them 
work fine on short pstn lines (where echo is much less of a problem), 
but provided even reasonable service on longer pstn lines or lines that 
involve unusual telco configurations (eg, remote line concentrators).

R.