add your SG# in GV
your phone
your phone -> SPA1001 ATA (set GV # as the caller ID) -> domestic/international out going calls are 1.9 cent per minute
Callers will always see your GV#, and the SG # is hidden to them.
Better to remove voice mail/call forwarding from SG.
Disable the "call presentation" in GV.
You can also call international numbers in GV (2 cent per min).
