我的設置， 免費US電話

call in
the world --> GV --> sipgate --> SPA1001 ATA line 1 --> phone

call out
phone --> SPA1001 ATA line 2 --> voipdiscount --> the world (CID GV #)

For 10 Euro the domestic US calls are free, either way. To call China it's 1c/min.

Working on callbacks in Sipsocery to allow cheap calls from China.

Thanks a lot, fitwxc.