How configure FXS port?

Hi, i have everything working but when i dial the FXS port, it just ring a half, i mean, 1/2 ring tone and then hangup…
Other thing, when i try to call via the FXS port, i can hear anything…

i have configured well the ports, i saw in dahdi_tools

Howdy,

For problems with Digium telephony cards, please contact our Support department directly:

digium.com/support

Cheers.

Well -.-’ that’s not the answer i was waiting :S
Me fxs port was working fine… the last year :S